application to the department of envrionment and heritage ...€¦ · application to the department...

APPLICATION TO THE DEPARTMENT OF ENVIRONMENT AND HERITAGE (DEH) ON THE

PILBARA FISH TRAWL INTERIM MANAGED FISHERY

Against the Australian Government Guidelines for the Ecologically Sustainable Management of

Fisheries

For Consideration Under Part 13 and 13A of the Environment Protection and Biodiversity

Conservation Act 1999

JULY 2004

DEPARTMENT OF FISHERIES, WESTERN AUSTRALIA LOCKED BAG 39, CLOISTERS SQUARE PERTH WA 6850

Application to DEH - Pilbara Fish Trawl Interim Managed Fishery

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TABLE OF CONTENTS

TABLE OF CONTENTS........................................................................................... 2 TABLE OF FIGURES ........................................................................................... 5 TABLE OF TABLES ............................................................................................ 6

1. INTRODUCTION TO THE APPLICATION ...................................................... 7

1.1 DESCRIPTION OF INFORMATION PROVIDED ........................................... 7 1.2 OVERVIEW OF APPLICATION....................................................................... 8

2. BACKGROUND ON THE PFTIMF ..................................................................... 9

2.1 DESCRIPTION OF THE FISHERY ................................................................... 9 2.1.1 Location of the Fishery................................................................................. 9

2.1.1.2 Functional Fishing Grounds................................................................. 10 2.1.2 Number of Licensees .................................................................................. 10 2.1.3 Description of Gear ..................................................................................... 10

2.1.3.1 General................................................................................................. 10 2.1.3.2 Operating Description.......................................................................... 10

2.1.4 Catch and Effort in the PFTIMF................................................................. 11 2.1.5 Species Caught ............................................................................................ 12

2.1.5.1 Target ................................................................................................... 12 2.1.5.2 By-Products.......................................................................................... 12 2.1.5.3 Non-retained species............................................................................ 13

2.1.6 Bait usage and packaging............................................................................ 15 2.1.7 Traditional involvement in the fishery........................................................ 15

2.2 HISTORY OF THE FISHERY.......................................................................... 15 2.2.1 Japanese trawl fishery................................................................................. 16 2.2.2 Taiwanese trawl fishery.............................................................................. 16 2.2.3 Domestic Trawl Fishery.............................................................................. 16 2.2.4 The Pilbara Trap Fishery and Line Fishing under the authority of a WA FBL ...................................................................................................................... 18

2.3 RECREATIONAL FISHERY ........................................................................... 19 2.3.1 General Description .................................................................................... 19 2.3.2 Issues associated with the recreational fishery ........................................... 19

2.4 MAJOR ENVIRONMENTS ............................................................................. 19 2.4.1 Physical Environment ................................................................................. 19 2.4.2 Significant environmental characteristics of the area of the fishery........... 20 2.4.3 Social Environment..................................................................................... 20 2.4.4 Economic Environment ............................................................................... 20

2.5 CURRENT AND PROPOSED MANAGEMENT ARRANGEMENTS .......... 21 2.5.1 Summary of management strategies and justification ................................ 21 2.5.2 Legislation and policies affecting the Fishery ............................................ 21 2.5.3 Bycatch Action Plan.................................................................................... 22 Preliminary work on a bycatch action plan for the fishery commenced in March 2002 with a discussion paper on bycatch management in the PFTIMF being sent to stakeholders for review however, the bycatch action plan cannot be completed until trials of mitigation devices has been completed. ......................................... 22 2.5.4 Code of Conduct ......................................................................................... 23

2.6 RESEARCH STRATEGY................................................................................. 23


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2.6.1 Recent/current research............................................................................... 23 2.6.2 Proposed/future research............................................................................. 23

2.7 BIOLOGY OF SPECIES ................................................................................... 24 2.7.1 Biology of Target species ........................................................................... 24

2.7.1.1 Lutjanidae............................................................................................. 24 2.7.1.2 Serranidae (tribe : Epinephalinae)........................................................ 28 2.7.1.3 Lethrinidae ........................................................................................... 29 2.7.1.4 Nemipteridae ........................................................................................ 30 2.7.1.5 Sparidae................................................................................................ 31

2.7.2 Biology of significant non-target species ................................................... 31 2.7.2.1 Dolphins ............................................................................................... 31 2.7.2.2 Turtles .................................................................................................. 32 2.7.2.3 Sea Snakes............................................................................................ 35 2.7.2.4 Seahorses and Pipefish......................................................................... 36 2.7.2.5 Non-retained Scalefish......................................................................... 37 2.7.2.6 Moray Eels ........................................................................................... 39 2.7.2.6 Sharks, Rays and Sawfish.................................................................... 39

3. METHODOLOGY ................................................................................................ 42

3.1 SCOPE............................................................................................................... 42 3.2 OVERVIEW ...................................................................................................... 42 3.3 ISSUE IDENTIFICATION (component trees) ................................................. 43 3.4 RISK ASSESSMENT/PRIORITISATION PROCESS..................................... 44 3.5 COMPONENT REPORTS ................................................................................ 45

4. ASSESSMENT OF THE PFTIMF MANAGEMENT REGIME AGAINST THE AUSTRALIAN GOVERNMENT GUIDELINES FOR ASSESSING THE ECOLOGICALLY SUSTAINABLE MANAGEMENT OF FISHERIES ........... 47

4.1 GENERAL REQUIREMENTS OF THE GUIDELINES ................................. 47 PRINCIPLE 1 OF THE AUSTRALIAN GOVERNMENT GUIDELINES ........ 51

OBJECTIVE 1. MAINTAIN VIABLE STOCK LEVEL OF TARGET SPECIES 51 OBJECTIVE 2. RECOVERY OF STOCKS........................................................... 63

PRINCIPLE 2 OF THE AUSTRALIAN GOVERNMENT GUIDELINES ........ 63

OBJECTIVE 1. BYCATCH.................................................................................... 63 OBJECTIVE 2. PROTECTED/LISTED SPECIES ................................................. 67 OBJECTIVE 3. GENERAL ECOSYSTEM ............................................................ 72

5. PERFORMANCE REPORTS .............................................................................. 82

5.1 RETAINED SPECIES ....................................................................................... 82 COMPONENT TREE FOR THE RETAINED SPECIES................................... 82 5.1.1 Primary Species........................................................................................... 82

5.1.1.1 Long- lived Species............................................................................... 82 5.1.1.2 Short-lived Species .............................................................................. 92

5.1.2 By-product Species ..................................................................................... 99 5.1.2.1 Other Scalefish..................................................................................... 99 5.1.2.2 Elasmobranchs ................................................................................... 101 5.1.2.3 Bugs ................................................................................................... 106 5.1.2.4 Cephalopods....................................................................................... 107 5.1.2.5 Shells .................................................................................................. 108


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5.2 Non-Retained Species...................................................................................... 111 Component Tree for the Non-Retained species in the PFTIMF ........................ 111 5.2.1 Protected/Listed Species ........................................................................... 111

5.2.1.1 Dolphins ............................................................................................. 111 5.2.1.2 Turtles ................................................................................................ 115 5.2.1.3 Seasnakes ........................................................................................... 119 5.2.1.4 Syngnathids ........................................................................................ 121 5.2.1.5 Sawfish............................................................................................... 125

5.2.2 Other Species ............................................................................................ 129 5.2.2.1 Moray Eels ......................................................................................... 129 5.2.2.2 Unmarketable Scalefish ..................................................................... 130 5.2.2.3 Elasmobranchs ................................................................................... 132 5.2.2.4 Macro- invertebrates ........................................................................... 134

5.3 General Environment ....................................................................................... 137 Component Tree for the General Environment for the PFTIMF....................... 137 5.3.1 Removal of/Damage to Organisms ........................................................... 137

5.3.1.1 Trophic Interactions ........................................................................... 137 5.3.1.2 Sand Infauna (Microbenthos) ............................................................ 139 5.3.1.3 Large Epibenthos (Macrobenthos)..................................................... 139

5.3.2 Addition or Movement of Biological Material ......................................... 149 5.3.2.1 Translocation...................................................................................... 149 5.3.2.2 Discarding/Provisioning .................................................................... 150

5.3.3 Other Environmental Impacts ................................................................... 151 5.3.3.1 Exhaust Fumes ................................................................................... 151 5.3.3.2 Debris ................................................................................................. 151

5.4 GOVERNANCE.............................................................................................. 152 COMPONENT TREE FOR THE GOVERNANCE.............................................. 152

5.4.1 Department of Fisheries – Management ................................................... 152 5.4.1.1 Management Effectiveness (Outcomes) ............................................ 152 5.4.1.2 Management Arrangements ............................................................... 155 5.4.1.3 Compliance ........................................................................................ 160 5.4.1.4 Allocation Among Users.................................................................... 162

5.4.2 Department of Fisheries – Consultation ................................................... 165 5.4.2.1 Consultation (including communication) .......................................... 165

5.4.3 Department of Fisheries - Reporting.................................................. 167 5.4.3.1 Assessment and Reviews ................................................................... 167

5.4.4 Department of Fisheries – Legal Framework ........................................... 169 5.4.4.1 OCS Arrangements ............................................................................ 169

6. REFERENCES..................................................................................................... 171

Appendix 1 Acronyms ............................................................................................. 178

Appendix 2 Details of Consequences Table ........................................................... 179


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TABLE OF FIGURES Figure 1. Demersal scalefish fisheries of the Pilbara region of Western Australia. ..... 9 Figure 2. Effort allocation by Area within the Pilbara Fish Trawl Fishery. ............... 12 Figure 3. The location of trawl shots (*) carried out in the 2002 bycatch survey in

each area of the fishery. Four dolphins were taken in Area 1 (locations marked by blue dots)......................................................................................................... 14

Figure 4. The location of turtle nesting sites with reference to the PFTIMF. Rosemary Island (Hawksbill Turtles); Varanus Island (Hawksbill Turtles); Muiron Islands (Green turtles and Loggerhead turtles); Northwest Cape (Green turtles); Barrow Island (Green turtles); Montebello Islands (Green turtles)........ 15

Figure 5. Annual catches (tonnes) and catch rates (kg/hour) of the Japanese fishery (1960-1962), the Taiwanese fishery (1972 to 1989), and the domestic fishery (1989-2001).......................................................................................................... 18

Figure 6. Summary of the ESD reporting framework processes. ............................... 43 Figure 7. Example of a component tree structure. ...................................................... 44 Figure 8. Annual catches and catch rates of the six major, long-lived, target species

caught by the PFTIMF, 1989-2002...................................................................... 56 Figure 9. Annual catches and catch rates of the six major, long-lived, target species

caught by the PFTIMF, 1989-2002...................................................................... 87 Figure 10. Spawning biomass (with 95% confidence intervals) as a percentage of the

1972 level (black line); the biological reference point (40% of the 1972 level – dotted line); and the catch from all fishing sectors (columns) for red emperor in the Pilbara fishery. Data from 2003 onwards is projected from the model. ........ 89

Figure 11. Spawning biomass (with 95% confidence intervals) as a percentage of the 1990 level (black line); the biological reference point (40% of the 1990 level – dotted line); and the catch from all fishing sectors (columns) for Rankin cod in the Pilbara fishery. Data from 2003 onwards is projected from the model. ........ 90

Figure 12. Spawning biomass (with 95% confidence intervals) in Area 1 as a percentage of the 1993 level (black line); the biological reference point (40% of the 1993 level – dotted line); and the catch from all fishing sectors (columns) for blue-spot emperor in the Pilbara fishery. Data from 2003 onwards is projected from the model. .................................................................................................... 97

Figure 13. Annual retained catch of sharks by the PFTIMF and total annual catch of sharks in WA (all fisheries), 1985-86 to 2000-01.............................................. 103


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TABLE OF TABLES Table 1 Recent annual catches of target scalefish species and major by-product

species by the PFTIMF. ....................................................................................... 13 Table 2 Comparison of Trawl Operations on North West Shelf. ............................... 17 Table 3 The number of hours allocated, the number of hours used and the percentage

of the allocation used in each area of the PFTIMF. ............................................. 17 Table 4 Main National ESD Reporting Framework Components. ............................. 42 Table 5 Risk ranking definitions. ................................................................................ 45 Table 6 The National ESD reporting framework headings used in this report........... 46 Table 7 Indicators for major long- lived target species a) total estimated spawning

biomass (SB) as a percentage of virgin level; b) ratio of annual catch to average of annual catch in previous 4 years; c) ratio of annual catch rate to catch rate in previous year. Years in which these indicators would have triggered a review are shown. .................................................................................................................. 55

Table 8 Indicators for major short- lived target species............................................... 58 Table 9 Summary of catches of protected/listed species in the Pilbara region........... 68 PFTIMF catches estimated from 2002 bycatch survey (Stephenson and Chidlow ..... 68 2003). ........................................................................................................................... 68 Table 10 Summary of risk assessment outcomes for environmental issues related to

the PFTIMF.......................................................................................................... 73 Table 11 Indicators for major long- lived target species. ............................................ 85 Table 12 Commercial catches (to the nearest tonne) and the percentages (to the

nearest 1%) of each major species taken by trawl, trap and line in the Pilbara in 2002...................................................................................................................... 86

Table 13 Summary of effort in the PFTIMF. Trawl effort (days) is from monthly catch and effort returns, hours is nominal “net bottom time” effort from operators’ logbook data, and VMS hours is the time vessels spend inside the boundaries of the fishery. ..................................................................................... 88

Table 14 Indicators for major short- lived target species............................................. 94 Table 15 Catches of all species reported by the PFTIMF, and total Western

Australian (WA) state catch by all fisheries in 2002. ........................................ 100 Table 16 Shark species retained during the 2002 bycatch survey and estimated

retained catches of each species by the PFTIMF fishery in 2002 (estimated by applying survey proportions to the total retained catch of 69 t). ....................... 104

Table 17 Main species of scalefish discarded by the PFTIMF and annual discarded catch, as estimated from bycatch survey. The total WA catch (i.e. amount retained by all WA commercial fisheries) is also shown. .................................. 131

Table 18 Annual catches of main species of discarded elasmobranchs caught by the PFTIMF, estimated from results of 2002 bycatch survey. ................................. 133

Table 19 Species of rays caught and discarded during the 2002 bycatch survey, and estimated annual fishery catch. .......................................................................... 134

Table 20 Estimated annual rate of mortality of large (>20 cm) attached epibenthos within 6 x 6 nm grids within fishery Areas (from Moran and Stephenson 2000)............................................................................................................................. 145

Table 21 Annual fishery catch* of each epibenthic species, estimated from results of 2002 Bycatch Survey (Stephenson and Chidlow 2002), and locations of highest catch rates in the survey area. ............................................................................ 146

Table 22 Objects of the FRMA. ................................................................................ 156


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1. INTRODUCTION TO T HE APPLICATION

1.1 DESCRIPTION OF INFORMATION PROVIDED This is an application to the Department of Environment and Heritage (DEH) to assess the Pilbara Fish Trawl Interim Managed Fishery (PFTIMF) against the Australian Government Guidelines For The Ecologically Sustainable Management Of Fisheries. The submission of a successful application against these guidelines is now needed to meet the requirements under Part 13 and 13A of the Environment Protection and Biodiversity Conservation Act, 1999 (EPBC), to enable the rankin cod (Epinephelus multinotatus) red emperor (Lutjanus sebae), scarlet perch (Lutjanus malabaricus), goldband snapper (Pristipomoides multidens), red snapper (Lutjanus erythropterus), spangled emperor (Lethrinus nebulosus), blue-spot emperor (Lethrinus hutchinsi), rosy threadfin bream (Nemipterus furcosus), flagfish (Lutjanus vitta) and frypan snapper (Argyrops spinifer) and other relevant by-products of this fishery to remain on section 303DB list of species exempt from export regulations (previously Schedule 4 of the Wildlife Protection (Regulation of Exports and Imports) Act, 1982). The information provided in this application cove rs all the elements specified in the Australian Government Guidelines for the Ecologically Sustainable Management of Fisheries along with other information (at a variety of levels of complexity) considered relevant to those who wish to gain an understanding of the management of this fishery. The application includes:

• Comprehensive background information on the history of the PFTIMF, the biology of the primary species and a description of the current management arrangements, which provides the context for assessing this application (see Section 2 for details).

• A description of the National Ecologically Sustainable Development (ESD) Reporting Framework and methodology that was used to generate the information presented in the application (see Section 3 and www.fisheries-esd.com for details).

• Specific supporting statements relevant to each of the criteria within the Guidelines. These criteria include the “General Requirements”, which cover many of the governance aspects related to the management of the PFTIMF, plus each of the objectives listed under “Principle 1” (target species issues) and “Principle 2” (broader ecosystem issues) of the Guidelines (see Section 4).

• Section 4 also has, where appropriate, specific links and reference to the detailed component reports contained in Section 5. {Referral to this additional information is facilitated by the incorporation of appropriately placed hyperlinks (electronic version only)}.

• Section 5 includes a comprehensive account of the risk assessment outcomes and current performance presented in the National ESD format as outlined in the Department’s ESD Policy (Fletcher, 2002). This covers each of the environmental and governance issues relevant to this application for this fishery.


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1.2 OVERVIEW OF APPLICATION The PFTIMF principally targets the lower value species such as blue spot emperor and threadfin bream. In 2002 the fishery landed a total of 2,310 tonnes of demersal scalefish, for a catch value of $7.6 million. The Fish Resources Management Act, 1994 (FRMA) provides the legislative framework for the Pilbara Fish Trawl Interim Managed Fishery Management Plan 1997. The fishery has been operating under a interim management regime since 1997 using a comprehensive set of regulations that include input controls such as gear restrictions, area closures and total and area effort limitations. Each of these has been refined through time, and is subject to regular reviews to achieve the overall aim of successful management. The combination of having a large amount of relevant and accurate information on the biology of the main finfish species, the sophisticated suite of management arrangements in place and the proactive management used in the fishery has resulted in the maintenance of stocks as well as the successful continuation of the fishery. Consequently, the management regime for the PFTIMF should meet the Australian Government Guidelines for the Ecologically Sustainable Management of Fisheries. Detailed justification for this conclusion is documented within the remainder of this application.


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2. BACKGROUND ON THE PFTIMF

2.1 DESCRIPTION OF THE FISHERY

Figure 1. Demersal scalefish fisheries of the Pilbara region of Western Australia.

2.1.1 LOCATION OF THE FISHERY The PFTIMF (Tw) coexists with the Pilbara Trap Managed Fishery (Tp). The Pilbara Trap Managed Fishery (PTMF) and the PFTIMF occupy the waters north of latitude 21o35’ S and between longitudes 114o9’36 E and 120o E. The PFTIMF approximates a polygon seaward of the 50m isobath and landward of the 200 m isobath (Figure 1).

The trawl fishery consists of two zones. Zone 1 in the south west of the fishery and Zone 2 in the north which contains six management Areas. Zone 1 of the trawl fishery has been closed to trawling since 1998 primarily because it was recognised as trap fishing ground and therefore, an opportunity for sectoral division between trap and trawl operators (Moran et al. 1995). In addition, Zone 2 Area 6 was open to research trawling in 1998 and 1999 but has since then been closed.

Management Areas 1 to 5 of Zone 2 are adjacent and numbered in a west-east direction, from 116o E to 120o E, and approximately between the 50 m to the 100 m isobath. Area 6 lies north of Areas 1 to 5 from approximately the 100 m to the 200 m isobath. The area of the PTMF is 25,400 square nautical miles. The total trawl area is


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14,980 square nautical miles and Areas 1 to 6 have areas of 1300, 1800, 880, 1500, 2300 and 7200 square nautical miles, respectively.

2.1.1.2 FUNCTIONAL FISHING GROUNDS Vessels target productive open ground or grounds adjacent to areas of relief such as rises, ridges and reefs, but generally avoid rough ground. There are several voluntary trawl closures, instigated by trawl operators that are intended as areas of habitat protection and recreational fishing, eg. Glomar shoals. There are some exclusion zones around gas pipelines and facilities. Currently, 80% of the PFTIMF is closed to trawling and has been closed to trawling since the implementation of the management plan in 1997/98. Areas 1, 2, 4 and 5 are open all year, with different effort allocations in each Area, as stipulated in the management plan. Area 3 is currently closed to fishing to limit fishing mortality on the longer-lived species like Rankin cod and red emperor. There has been no effort allocation in Area 6 since the end of 1998. Most of the fishery is trawled with varying intensity due to variable spatial effort allocation and the nature of the ground. At present the fleet consistently covers Areas 1, 2, and 4 but only about 80% of Area 5 is trawled consistently.

2.1.2 NUMBER OF LICENSEES

There are 11 licences to operate in the fishery. However, the fishery is managed under an individual transferable effort (ITE) regime and current effort levels are such that there is the equivalent of 4.3 full time vessels operating in the fishery (assuming 225 days of effort per year per vessel).

2.1.3 DESCRIPTION OF GEAR 2.1.3.1 GENERAL The vessels in the fishery tow one net with two otter boards. The net towed by the vessel must be of mesh size exceeding 100 mm, with a headrope length not exceeding 36.58 m, and with the overall trawl gear (including sweeps, bridles, and headropes) not exceeding 274.32 m.

The ground (or foot) rope of the net opening has rollers or bobbins attached which must be not more than 350 mm in diameter. These are placed about a third of a metre apart along the ground rope. The bottom rope is weighted so that the bobbins contact the sea floor to enable the bottom dwelling species to be caught. The weighted ground rope is integral to the fishing process, and also has an impact on the bottom habitat.

2.1.3.2 OPERATING DESCRIPTION The location and duration of trawl shots; the catch of target species, and the total catch is recorded on a skippers logbook. The shot duration is 0.5 to 5 hours with a


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modal time of 3 hours. The net is retrieved on a net drum, with the catch being spilled on the deck or alternatively below deck through a hopper. The catch is sorted by species, then the weight of the catch and catches of the main species are estimated. The catch is then transferred to a brine tank for chilling. A few hours later, the catch is transferred to a cold room and packed by species into polythene- lined tubs (~20 kg per tub). The catch is held at 1oC - 4oC to ensure a shelf life of 14 days.

Shot locations are recorded on a plotter and colour-coded by date for future reference. The boundaries of the fishery are also plotted to ensure compliance with the management plan.

Trip duration is generally 5–9 days, after which the catch is weighed and recorded by species on the jetty or in the processor facility. It is then loaded on chiller trucks for transport to Perth. The catch typically arrives in Perth for auction 2-7 days after being caught.

Trawl fishing occurs all year, but with reduced effort in April and May when most vessels move to operate in the Nickol Bay Prawn Managed Fishery. The scallop season can also affect the temporal fishing pattern if vessels move to operate in the Shark Bay or Abrolhos Islands scallop fisheries. Around December to March, cyclones are more common, and trawl fishing may be interrupted by bad weather.

2.1.4 CATCH AND EFFORT IN THE PFTIMF The total allocated effort in each of the areas in the PFTIMF is illustrated in Figure 2. Catch and effort statistics are reported by fishers in compulsory monthly catch and effort summaries (CAES). Catches (in kg) are reported by species and by trip. Also, a voluntary logbook system has been used in the Fishery since 1991 for skippers to record all retained and non-retained species. All skippers currently complete logbooks, in which they report catches (in kg) of major species and bycatch (including listed species) by trawl shot, the time and location of each shot and net bottom time (in hours). Additional effort data is available from a vessel monitoring system (VMS), which was introduced in 1998 and allows monitoring of the time spent per vessel in each area of the fishery.

Between 1998 and 2001, annual effort allocation and expenditure in Area 1 was significantly reduced (from 17,136 to 10,624 allocated hours), while effort in other Areas remained relatively constant among years (Table 3). Effort expended within Area 1 is currently about twice that of any other Area. From 1998 to 2001, annual allocations of effort were slightly over-utilised in Areas 2 and 4, and under utilised in Areas 1 and 5. In 2001, the fishery nearly used the entire allocated effort.

Catches and catch rates by Pilbara trawl fishers declined rapidly from 1973 until cessation of the foreign fishing in 1989 (Figure 5). Domestic catches increased from 1989 to 1996 then declined until 2000. The catch rates increased from 1990 to 1994, then stabilised from 1996 to 2001.

The catch of blue-spot emperor has decreased in recent years, mainly due to effort reduction, and also reduced catch rates in Area 1. The catch of scarlet perch and goldband snapper were reduced for several years but showed a dramatic increase in 2001. Red snapper and flagfish catch also increased in 2001. Rankin cod and spangled emperor catches have declined dramatically in recent years. Catch rates of frypan snapper and red emperor have all declined in recent years.


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Figure 2. Effort allocation by Area within the Pilbara Fish Trawl Fishery.

2.1.5 SPECIES CAUGHT 2.1.5.1 TARGET The target species in the fishery tend to fall into two categories: either high value (high value species caught in moderate numbers), or high volume (usually medium to low value species caught in higher numbers). The high value species include red emperor, scarlet perch, spangled emperor, Rankin cod and goldband snapper (Table 1). Current management strategies aim to limit fishing mortality of these species through effort quotas. The high volume species include blue spot emperor (mainly targeted in Area 1), rosy threadfin bream, flagfish, frypan snapper, and red snapper. 2.1.5.2 BY-PRODUCTS Retained byproduct in the PFTIMF includes various species of sharks, bugs (Thenus orientalis) and cuttlefish (Table 1). Numerous species of scalefish, in addition to those listed as target species, are caught in minor quantities and retained as by-product (Table 1). The amount of shark by-product varies between vessels, with some sending most sharks to market and others discarding most sharks. The large sharks are generally retained. At the markets, some sharks are unsaleable mainly due to discolouration of the flesh. Pharaohs cuttlefish (Sepia apama) is caught and retained for export to Asia. Approximately 0.3 tonnes of arrow squid (Lolligindae) are also caught per year and sold fresh on domestic markets.


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Table 1 Recent annual catches of target scalefish species and major by-product species by the PFTIMF.

Annual catch (t) Target/byproduct? Species 1998 1999 2000 2001 2002 High value/volume?

Red emperor (Lutjanus sebae) 93 77 68 74 79 Target; high value Rankin cod (Epinephelus multinotatus) 31 32 25 19 17 Target; high value

Scarlet perch (Lutjanus malabaricus) 85 70 64 88 82 Target; high value Goldband snapper (Pristipomoides multidens) 103 82 75 122 99 Target; high value

Spangled emperor (Lethrinus nebulosus) 34 29 26 24 19 Target; high value

Red snapper (Lutjanus erythropterus) 314 229 252 365 278 Target; low value, high volume

Flagfish (Lutjanus vitta) 202 183 167 171 211 Target; low value

Bluespot emperor (Lethrinus hutchinsi) 489 441 400 318 353 Target; low value, high volume

Rosy threadfin bream (Nemipterus furcosus.) 295 209 187 228 363 Target; low value, high volume

Frypan snapper (Argyrops spinifer) 78 58 46 42 42 Target; low value

Total scalefish catch 2733 2326 2074 2221 2310

Sharks and rays (various species) 69 63 52 73 68 Byproduct

Bugs (Thenus orientalis) 4 3 3 7 5 Byproduct

Squid (Lolloginidae) 0 0 0 3 2 Byproduct

Cuttlefish (Sepia pharaonis) 45 28 22 67 104 Byproduct

2.1.5.3 NON-RETAINED SPECIES Discarded bycatch is generally not recorded on skippers logbooks, although some skippers do record total discarded scalefish. Quantitative information on trawl bycatch from the Pilbara region is available from extensive CSIRO surveys undertaken during the 1980s and 1990s. Also, in 2002, the Department of Fisheries conducted a Bycatch Observer Survey in the PFTIMF (Stephenson and Chidlow 2003). This survey recorded catches of by-product and non-retained species and also monitored the interaction of trawl vessels with dolphins through the use of underwater video cameras.

Available data indicates that discarded bycatch of the fishery is mainly comprised of triggerfish, lizardfish, small sharks, rays and other unmarketable scalefish species. Discards also include small quantities of moray eels, lobsters, crabs, octopi, pipefish and seahorses.

Protected/listed species that may occasionally be caught by the fishery are listed below. (acronyms refer to the legislative Acts which afford each species its protected status)

• Dolphins (EPBC 1, WCA2) • Sea snakes (EPBC) • Marine turtles (EPBC) • Seahorses, sea dragons and pipefish (EPBC) • Sawfish (IUCN Red List of threatened species)

1 Environment Protection and Biodiversity Conservation Act 1999. 2 Wildlife Conservation Act 1950.


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Figure 3. The location of trawl shots (*) carried out in the 2002 bycatch survey in each area of the fishery. Four dolphins were taken in Area 1 (locations marked by blue dots).

Between 50 and 100 dolphins are caught annually and are usually dead when brought to the deck (the location of dolphins takebn in the Department’s 2002 bycatch survey are shown in Figure 3). Sawfish are caught occasionally, and are generally killed by the crew in order to safely remove them from the net. Sea snakes and turtles are occasionally caught and generally returned alive to the sea. All of the turtle nesting grounds in the north-west are within zones of the fishery that are closed to trawling (Figure 4). However, turtles are migratory so the Department is making the collection of data (including the take of turtles), and the development and trailing of mitigation measures first priority throughout the fishery. The discarded catch also includes large epibenthic organisms such as sponges, sea whips and gorgonians.


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Figure 4. The location of turtle nesting sites with reference to the PFTIMF.

Rosemary Island (Hawksbill Turtles); Varanus Island (Hawksbill Turtles); Muiron Islands (Green turtles and Loggerhead turtles); Northwest Cape (Green turtles); Barrow Island (Green turtles); Montebello Islands (Green turtles).

2.1.6 BAIT USAGE AND PACKAGING Bait is not used in this fishery.

2.1.7 TRADITIONAL INVOLVEMENT IN THE FISHERY There is no traditional involvement in the fishery.

2.2 HISTORY OF THE FISHERY Since the 1990s, the majority of the demersal scalefish taken off the North-West Shelf have come from the PFTIMF, with relatively minor contributions from the trap and line fisheries. Of the 2,586 tonnes of demersal scalefish landed in 2001, the trawl fishery caught 2,221 tonnes.

The North-West Shelf has a long history of commercial trawling (Table 2). The practices of previous fleets, in particular the Taiwanese Pair Trawlers, differ markedly


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to the current fishing practices of the PFTIMF, in the area fished, amount of fishing effort, and size and weight of fishing gear.

The history of trawl in the Pilbara has been described in detail elsewhere (Sainsbury 1987). The main features of these fisheries are as follows:

2.2.1 JAPANESE TRAWL FISHERY A Japanese stern trawl fishery existed in the Pilbara from 1959 to 1963 and mostly operated between 116o E and 117o30 E. This fishery targeted fish of the genus Lethrinus, which comprised about half of the catch weight. Although catch rates did not decline during the period of the fishery, there was a considerable change in the size composition of Lethrinids, with animals heavier than 0.6 kg disappearing from the catch after 8 months of fishing. This may have been due to the loss of L. nebulous from the catch (Sainsbury 1987). A total of about 7,600 hours of trawling was exerted during the about 3 year duration of the fishery, for a total catch of about 16,700 tonnes.

2.2.2 TAIWANESE TRAWL FISHERY A Taiwanese pair trawl fishery commenced in 1972 taking a wide range of species. Operations were widespread but mainly between 115o E and 120o E, in depths between 30 and 140 m. Typically vessels paired to tow a 30 m headline net on 850 m of wire cable. Codend mesh sizes of about 45 mm were common until the introduction of 60 mm minimum mesh size in 1981 (Sainsbury and Whitelaw 1984). The retained catch mostly comprised the genera Nemipterus (threadfin bream), Saurida (lizard fish), Lutjanus (tropical snapper), and Lethrinus (tropical emperors) (Liu and Lai 1978). Research by CSIRO indicated that the species composition changed in the 1970s and 1980s. There was a decreased abundance of large snappers and emperors and an increased abundance of threadfin bream and lizardfish, with the change in species composition being most likely due to habitat modification (Sainsbury 1991).

A logbook programme to record fishing effort and retained catch by broad commercia l category was initiated by the Taiwan University in 1974, and the Australian Federal Department of Primary Industry collected similar records from 1979. During the first five years of the fishery the annual catch was 20,000 - 30,000 tonnes with an annual effort of 45,000 to 80,000 hours. The catch decreased to about 8,000-15,000 tonnes with reduced effort levels of 25,000 to 41,000 hours in the later years of the fishery. This fishery ceased in 1989. There is no information available on discards.

2.2.3 DOMESTIC TRAWL FISHERY Domestic demersal trawling operations began in 1989 with a catch of 133 t, and then rapidly expanded to 3200 t in 1996. Vessels were originally endorsed to operate through their Fishing Boat Licences and the 11 vessels operating in the fishery during the mid 1990s were recognised as the Pilbara Fish Trawl Fishery. In 1998, the fishery moved to Interim Managed status and formalised as the PFTIMF.


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The PFTIMF catch peaked at 3210 tonnes in 1996, with 34116 hours effort (adjusted to Vessel Monitoring System equivalent effort units). In 2001, the catch was 2221 tonnes from 21,199 hours effort.

Table 2 Comparison of Trawl Operations on North West Shelf. Fishery Effort Catch

Japanese Trawl (1959-1963) 7,600 hrs over 3 yrs. 16,700 t over 3 yrs

Taiwanese Pair Trawl (1972-1989)

45,000-80,000 hrs per yr (1972-1976)

25,000-41,000 hrs per yr (1976-1989)

20,000-30,000 t per yr

8,000-15,000 t per yr

Pilbara Fish Trawl (domestic) (1980 +)

21,199-34,116 hrs per yr (1996-2002) 1,995-3,210 t per yr

Table 3 The number of hours allocated, the number of hours used and the

percentage of the allocation used in each area of the PFTIMF. Area 1 Area 2 Area 3 Area 4 Area 5 Total 1998 time allocation 17136 3,360 0 3,360 5,712 29,568

time used 15,076 3,842 0 3,736 4,955 27,609

% of time used 88% 114% - 111% 87% 93%

1999 time allocation 11,481 3,360 0 3,057 5,198 23,096

time used 10,237 3,767 0 3,213 4,973 22,190

% of time used 89% 112% - 105% 96% 96%

2000 time allocation 11,481 3,360 0 3,057 5198 23,096

time used 9,438 3,928 0 3,358 4476 21,199

% of time used 82% 117% - 110% 86% 92%

2001 time allocation 10,624 3,797 0 3,528 5141 23,090

time used 10,428 4,091 0 3,644 4819 23,000

% of time used 98% 108% - 103% 94% 100%

2002 time allocation 10,624 3,797 0 3,528 5141 23,090

time used 9040 3848 0 3624 4213 20,725

% of time used 85% 101% - 103% 82% 87%


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Figure 5. Annual catches (tonnes) and catch rates (kg/hour) of the Japanese

fishery (1960-1962), the Taiwanese fishery (1972 to 1989), and the domestic fishery (1989-2001).

2.2.4 THE PILBARA TRAP FISHERY AND LINE FISHING UNDER THE AUTHORITY OF A WA FBL A domestic trap fishery commenced in the early 1980s, taking 200-300 tonnes of fish per year. This fishery began operation in the western part of the shelf in areas subjected to little trawling (Moran et al. 1988). The trap fishery currently operates as the PTMF and is managed under an ITE regime. The trap fishery shares some target species and some fishing grounds with the trawl fishery. The trap fishery targets fishes of the genera Lethrinus (mainly L. nebulosus and occasionally L. hutchinsi) and Lutjanus (mainly L. sebae and Pristipomoides multidens), together with the serranids Plectropomus maculatus (coral trout) and Epinephelus multinotatus (tropical cod).

Line fishing (or “wetlining”) in the Pilbara is currently open access, and so any holder of a Western Australian fishing boat licence (WA FBL) has line access to the fish stocks. In practice, there has been limited catch by the line fishery (around100 tonnes) in the last 10 years however, it is estimated that the number of wetliners targeting demersal finfish stocks in the Pilbara has increased rapidly in recent months. There are currently no management arrangements in place to restrict the number of wetline vessels, wetline effort, or the area in which they can operate and the comprehensive review of wetline fishing in the Pilbara is not scheduled to begin until the review of wetline fishing in the Gascoyne and West Coast is finalised. However, the Department’s Research Division advises that a number of deepwater species in the Pilbara are vulnerable to over fishing and are unlikely to sustain further increases in catch. It estimates the total catch of goldband snapper from all groups should not exceed 180 tonnes per year and, with the 2003 catch around 130 tonnes, the concern is that any increase in wetline activity may be detrimental to this stock.

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For this reason the Department is in the initial stages of implementing a temporary prohibition on wetlining under section 43 of the FRMA as an interim measure to prevent any further increases in wetline activity until such time as the wetline review can fairly and equitably consider long-term access and allocation issues in the Pilbara. The temporary prohibition will apply to all WA FBLs and prohibit fishing by line from any licensed fishing boat in the waters between 22ºS (including Exmouth Gulf) and 120ºE (the boundary of the Northern Demersal Scalefish Fishery). Of course existing managed fishery operators in the region will be exempt from the prohibition so they may continue their usual operations and the Department has further identified a number of existing wetline boats (around 15) that are to be exempt from the prohibition.

2.3 RECREATIONAL FISHERY

2.3.1 GENERAL DESCRIPTION There is a significant amount of recreational and charter boat fishing activity in the Pilbara region. Most of this activity occurs inshore of the trawl fishery. A 12-month creel survey of recreational boat- and shore-based fishing in the Pilbara region was conducted in 1999-2000 (Williamson et al., in prep.). In the survey area (Onslow to Broome), total annual recreational fishing effort was estimated to be 190,000 fisher days. The total recreational scalefish catch was estimated to be 300 tonnes, which was equivalent to 12% of the total commercial (all sectors) scalefish catch in the survey area. Twelve tonnes of spangled emperor and 6 tonnes of red emperor were caught and retained by recreational fishers in the survey area. However, most of the species targeted by recreational fishers in the Pilbara are not among the target species of the trawl fishery. Furthermore, there are 85 fishing tour licences and 5 eco-tourism (i.e. non-extractive activities) licences in the Pilbara and Kimberley regions combined. In 2001, a logbook system was instigated to collect catch and fishing effort information from tour operators.

2.3.2 ISSUES ASSOCIATED WITH THE RECREATIONAL FISHERY There is significant spatial separation between the recreational and commercial fisheries and the Department has not identified any significant issues associated with resource sharing.

2.4 MAJOR ENVIRONMENTS

2.4.1 PHYSICAL ENVIRONMENT The substrate of the main fishing grounds of the fishery is variable and includes limestone ridges, coarse sand, mud and gravel bottoms (Harris and Baker 1988). The major vegetation types in the fishery are sparse beds of macro-algae and encrusting


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algae associated with some of the harder substrates. A diverse range of sessile epibenthic fauna (e.g. sponges, gorgonians, sea whips, soft corals) occur in the fishery. Epibenthic fauna provide structurally complex habitat that is used by many target species caught by the fishery. Demersal trawling is destructive to epibenthos, although the rate of trawl- induced mortality varies with the type of trawl gear used, and also with the size and morphology of epibenthic organisms. Demersal otter trawling (as conducted by the current domestic fishery) in the Pilbara region has been found to reduce large epibenthos (organisms >20 cm) density by 15.5% per trawl pass, although only 4% of the detached benthos is retained in the net (Moran and Stephenson 2000). At the 1999 level of effort, most of the trawl area was estimated to have a mortality of 0.5 - 10% per year, with some spots of higher mortality in Area 1 (where effort is concentrated). Unfortunately, rates of recruitment and growth are unknown for most epibenthic species, and so the impact on benthos populations of various levels of fishing mortality cannot be fully assessed. The composition of epibenthic communities in the Pilbara region is likely to have changed as a result of many decades of trawling. During operations of the Taiwanese fishery in the 1970s, Sainsbury et al. (1993) estimated that the trawl- induced mortality of large epibenthos in the region was 89% per trawl pass. This rate is much higher than estimated mortality in the current fishery. The difference may reflect the gear used in this fishing operation. It may also reflect a difference in epibenthos composition during the 1970s, compared with present-day communities.

2.4.2 SIGNIFICANT ENVIRONMENTAL CHARACTERISTICS OF THE AREA OF THE FISHERY

2.4.3 SOCIAL ENVIRONMENT Twenty fisherswere employed on Pilbara trawl vessels in 2001. Landings by the fishery provide significant support to the local fish processing industry and a significant portion of the catch is sold locally in Western Australia. There is also an increasingly important export of Pilbara scalefish to Europe and Asia.

2.4.4 ECONOMIC ENVIRONMENT

In 2001, the annual value of the entire Pilbara region scalefish catch (including trap, line and trawl fisheries) was approximately $9 million.

In 2001, total production of the PFTIMF was $7.4 million (or 82% of the Pilbara’s total production), including retained byproduct valued at $300,000.


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2.5 CURRENT AND PROPOSED MANAGEMENT ARRANGEMENTS

2.5.1 SUMMARY OF MANAGEMENT STRATEGIES AND JUSTIFICATION The fishery is managed through a combination of area closures, gear restrictions (see section 2.1.3) and effort limitations. Individual fishers are allocated transferable units of effort within each area of the fishery. Effort expenditure (Table 3) is monitored by a satellite-based VMS.

Since commencement of formal management arrangements in 1998, total effort has been reduced. Effort has also been redistributed among areas within the fishery with the aim of maximising yield whilst keeping exploitation rates of the indicator species (red emperor and Rankin cod) at sustainable levels. For example, effort has been reduced in areas of high red emperor abundance and redistributed to areas of high abundance of more robust, short-lived species.

There are a number of area closures within this fishery to minimize overlapping operation between the sectors and to limit fishing mortality on the longer- lived species. Zone 1 and Area 6 are closed to trawling. Area 3 is closed to trapping and trawling. The remaining Areas are open all year to fishing, but with differing levels of annual effort for the trap and line sector.

The management strategy allows for some flexibility within areas in terms of total trawl effort. Since 1998, annual trawl effort allocations have been exceeded in some areas, but not reached in other areas (Table 3). In 2002, amendments to the interim Management Plan limited the over-run of time in any area to no more than 48 hours per licence. Effort allocations in 2002 in Areas 1, 2, 4, and 5 were 10,624, 3,797, 3,528, and 5,141 hours, respectively.

The two indicator species, red emperor and Rankin cod, are considered representative of other longer- lived species (eg. spangled emperor, scarlet perch, goldband snapper) that have similar vulnerability to overfishing. Management actions to ensure sustainable catches of these two indicator species are considered likely to afford similar protection to other long- lived species. Blue-spot emperor is used as an indicator for the short-lived species. It is recognised by research, management and industry that a strategy of ensuring the sustainable harvest of long- lived species will result in the under-exploitation of some short- lived species (eg. threadfin bream, flagfish).

2.5.2 LEGISLATION AND POLICIES AFFECTING THE FISHERY

• Pilbara Fish Trawl Interim Managed Fishery Management Plan 1997. • Fish Resources Management Act 1994 (FRMA). • Fish Resources Management Regulations 1995 (FRMR). • Bycatch action plans • Environment Protection and Biodiversity Conservation Act 1999 (EPBC):

provides for the protection of species within one of four categories - threatened


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species; listed marine species; migratory species and cetaceans. Species listed as threatened under the Australian Government EPBC Act must have a recovery plan prepared for them.

2.5.3 BYCATCH ACTION PLAN Fishery members and the Department are committed to reducing the bycatch of listed species and have agreed on a three-phase process for achieving outcomes. The first phase involves the collection of baseline data (to clarify the extent of the problem); the second is the development and trialling of mitigation measures; and finally the implementation of new policy and management arrangements (including legislation). The process is expected to take three to four years in total. Current information on levels of turtle and dolphin bycatch is limited. The Department and industry have implemented an observer program which began with two on-board observer trips in June 2004. The intention of the long-term program is to collect data on the bycatch of listed species (in particular dolphins, turtles and sawfish). The program will provide improved baseline data which is required to show the impact of different mitigation devices trialled.

Furthermore, the Department has successfully secured funding from the Fisheries Research and Development Corporation (FRDC) to develop and trail bycatch mitigation devices. The Department proposes to begin trialling devices once extensive baseline data has been collected against which the effectiveness of the mitigation devices can be measured. This is expected to begin around December. The Department’s Research Division and members of the Fishery have agreed to trial grids of differing materials and sizes (to deter, or provide an escape mechanism for, turtles and dolphins), pingers (specifically designed to deter dolphins from trawl nets), and electro shark deterrents (to deter sharks and sawfish). The effectiveness of these devices will not only be measured against the baseline data but monitored by underwater digital cameras. In addition, digital cameras mounted on the deck of vessels will monitor the catch composition of the Fishery. The cameras record 24 hours a day and will give comprehensive footage of all catch and on-deck activity. On-board observers will initially operate concurrently with the on-deck digital cameras to verify the footage but the longer-term intention is to have a reduced on-board observer program to act as an audit of the footage only.

A bycatch action plan is being developed concurrently with the DEH ecological sustainability assessment and is intended to compliment this process without duplication. Development of the Plan is regarded as essential the fishery being able to demonstrate ecological sustainability when the exemption from the requirement to obtain a permit to export marine species, as provided for under Schedule 4 of the Wildlife Protection (Regulation of Exports and Imports) Act, 1982, ceases.

Preliminary work on a bycatch action plan for the fishery commenced in March 2002 with a discussion paper on bycatch management in the PFTIMF being sent to


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stakeholders for review however, the bycatch action plan cannot be completed until trials of mitigation devices has been completed.

2.5.4 CODE OF CONDUCT It is proposed that licencees of the fishery develop a Code of Conduct. This Code would be incorporated in the bycatch action plan, and promote fishing practices and fisher behaviours that minimise bycatch and maximise the survival of released species. The Code could also provide a vehicle to encourage

i) detailed reporting of the catches of protected species, ii) improved reporting of catches/discards of selected species in voluntary

logbooks, and iii) reporting of environmental/habitat data.

The Code could also be a vehicle to encourage fishing behaviours and handling practises that

i) improve product value, or ii) improve the public perception about the fishery.

2.6 RESEARCH STRATEGY

2.6.1 RECENT /CURRENT RESEARCH In 1993/94, a mortality experiment (Stephenson and Dunk 1996) was undertaken to determine the sustainable level of fishing effort in the fishery. Five key species were studied. Red emperor and Rankin cod were chosen as indicators to represent large, long- lived species with low natural mortality that were caught by the fishery. Flagfish, lesser spangled emperor and rosy threadfin bream were chosen to represent the smaller, short-lived species with high natural mortality.

A subsequent study (Stephenson and Mant 1999) determined age structure and biological characteristics for red emperor, Rankin cod, blue spot emperor, flagfish and rosy threadfin bream. The data was incorporated into a model that determined the likely impact of various levels of fishing effort on stocks of the key species, particularly red emperor and blue spot emperor.

In 1998, research surveys of the deeper areas adjacent to the existing trawl grounds were completed under a separate FRDC-funded project (Newman et al. 2000a). In 2002, the Department of Fisheries undertook a Natural Heritage-funded bycatch survey of the trawl fishery (Stephenson and Chidlow 2003).

2.6.2 PROPOSED/FUTURE RESEARCH A carefully structured sampling programme to re-assess the age composition of red emperor, Rankin cod, and goldband snapper catches began in June 2004. This involves the collection and processing of fish otoliths. The skipper logbook programme, which provides valuable spatial and temporal information on the catch of target species, will continue. In 2004, the logbook will be


24

expanded to allow skippers to record catches of other selected species, including protected species. An observer program has also commenced with the Department having carried out two on-board observer trips in June 2004 as part of a longer-term program to collect data on the bycatch of listed species (in particular dolphins, turtles and sawfish). The Department has successfully secured funding from the Fisheries Research and Development Corporation (FRDC) to develop and trail bycatch mitigation devices. The Department proposes to begin trialling devices once extensive baseline data has been collected against which the effectiveness of the mitigation devices can be measured. This is expected to begin around December 2004. The Department’s Research Division and members of the Fishery have agreed to trial grids of differing materials and sizes (to deter, or provide an escape mechanism for, turtles and dolphins), pingers (specifically designed to deter dolphins from trawl nets), and electro shark deterrents (to deter sharks and sawfish). The effectiveness of these devices will be monitored by underwater digital cameras as well as being measured against the baseline data. Furthermore, digital cameras mounted on the deck of vessels will monitor the catch composition of the Fishery. On-board observers will initially operate concurrently with the on-deck digital cameras to verify the footage but the longer-term intention is to have a reduced on-board observer program to act as an audit of the footage only.

2.7 BIOLOGY OF SPECIES

2.7.1 BIOLOGY OF TARGET SPECIES 2.7.1.1 LUTJANIDAE The Lutjanidae family contains 17 genera and 103 species that are commonly known as tropical snappers (Allen 1985). Most species occur in tropical and sub-tropical marine waters and are associated with reefs. They are carnivorous, typically preying on bottom-dwelling organisms and foraging mostly at night. Most lutjanids are highly fecund, broadcast spawners. Females release numerous batches of eggs over an extended spawning period. Fecundity increases with female size. Specific fecundity estimates are not available for all lutjanids, but a 100 cm female may typically produce 5-7 million eggs per year. Eggs and larvae are pelagic and usually occur in shallow continental shelf waters (Leis and Carson-Ewart 2000). Larvae typically migrate to the surface at night and away from the surface during the day. Red emperor (Lutjanus sebae) are widely distributed throughout the Indo-Pacific, ranging from eastern Australia to southern Japan and Western Australia, and westward to east Africa and the southern Red Sea (Allen 1985). Within Australia, red emperor range from Sydney, NSW, around the northern coast to Quinns Rock, WA.


25

No significant genetic differentiation has been observed among populations of red emperor across the north-west region of Australia based on allozyme studies (Johnson et al. 1993). In contrast, ratios of oxygen and carbon isotopes in otoliths of adults suggest very limited mixing of populations between the Pilbara and Kimberley regions (Stephenson et al. 2001). In summary, genetic homogeneity is probably maintained by the dispersal of pelagic eggs and larvae among regions, but juveniles and adults undertake limited movements. Limited movement by adults indicates that the current area-based management strategy for this species is appropriate and that regional populations should be treated as separate stocks for fishery management purposes. There may be some movement of red emperor offshore with increasing age. Juveniles (<20 cm length) are common in nearshore turbid waters and also occur on coastal or offshore reefs (Kailola et al. 1993). Sub-adult fish (>20 cm) are widely distributed across the continental shelf (Newman pers. obs.). Adults occur across the shelf to depths of at least 180 m and are associated with coral reef lagoons, reefs, epibenthic communities, limestone sand flats and gravel patches (Kailola et al. 1993). Adults may be solitary or form schools. They feed mainly on fish, benthic crustaceans and cephalopods (Allen 1985). Spawning occurs from October to March in the Kimberley region, with the main spawning period in October (Newman et al. 2001). Similarly, spawning occurs from September to December in the Pilbara region (Stephenson and Mant 1999). Newman et al. (2001) estimated a mean age-at-maturity of 8 y for both males and females, reflecting a mean size at maturity of 46.1 cm TL (total length) for females and 49.1 cm TL for males in the Northern Demersal Scalefish Managed Fishery (NDSMF). In contrast in the Pilbara region, Stephenson and Mant (1999) estimated that the mean size-at-maturity for females at 419 mm TL at a mean age of approximately 3.8 y. In addition, the estimated length-at-maturity for red emperor from the Great Barrier Reef was estimated to be 54.8 cm by McPherson et al. (1992). The size at maturity in the Pilbara region is similar to the minimum legal length in WA of 410 mm TL. Red emperor, like all lutjanids are gonochoristic. That is, they do not undergo sex change. Sexes remain separate throughout life. However, there is significant differential growth between sexes, with males on average reaching a larger size at age than females (Newman and Dunk 2002). Red emperor, attain a maximum length of at least 100 cm (Allen 1985). Maximum age is estimated to be at least 40 y, although the oldest age observed in the NDSMF is 34 y (Newman and Dunk 2002). Newman and Dunk (2002) estimated M for red emperor to be in the range 0.104-0.122 in the NDSMF. Similarly, Stephenson and Mant (1999) estimated M, to be 0.10 in the Pilbara region. These estimates of natural mortality are similar to those estimated for L. erythropterus and L. quinquelineatus based on an analysis of catch curves from unfished populations on the Great Barrier Reef (Newman at al. 1996, Newman et al. 2000b). Note both these species had similar longevities to that observed in red emperor populations from north-western Australia. Scarlet sea perch (Lutjanus malabaricus) are distributed throughout the Indo-Pacific region from Fiji to the Persian Gulf, and from Australia to southern Japan (Allen 1985). Within Australia, they are found from Shark Bay, WA, around the northern coast to Sydney, NSW. Movement of adult scarlet sea perch has not been studied, but


26

is likely to be similar to other lutjanid species, which have restricted long-shore movement. Therefore, the current area-based management strategy for this species is appropriate and regional populations should be treated as separate stocks for fishery management purposes. Juveniles are solitary and mainly occur in shallow nearshore waters, often associated with seagrass. Some juveniles also occur across the shelf. There is considered to be a general offshore movement of juveniles with increasing age (Kailola et al. 1993). Adults are found in continental shelf waters to depths to at least 140m. They are associated with coastal and offshore reefs, shoals, and areas of flat bottom with occasional benthos or vertical relief. On the north-west shelf of WA, they are often associated with sponge and gorgonian habitats and are often found schooling with L. erythropterus (red snapper) (Kailola et al. 1993). Scarlet sea perch feed mainly on fish and benthic crustaceans (Allen 1985). Scarlet sea perch have an extended spawning period. The timing of spawning varies among regions but there is a general peak in activity in spring/summer (Allen 1985). Scarlet sea perch are gonochoristic. That is, they do not undergo sex change. Sexes remain separate throughout life. However, there is significant differential growth between sexes, with males on average reaching a larger size at age than females (Newman 2002). Hence, males predominate among the larger individuals in the population, although the sex ratio does not change with age. The estimated length-at-maturity for scarlet seaperch from the Great Barrier Reef was estimated to be 57.6 cm by McPherson et al. (1992). The maximum length observed in the fishery is 802 mm, but they may reach 1000 mm (Allen 1985). Maximum age is estimated to be >40 y, although the maximum age observed in the fishery is 31 y. The rate of natural mortality, M, is estimated to be 0.11 (Newman 2002). Flagfish (Lutjanus vitta)

Flagfish are found mainly in the east Indian Ocean and western Pacific, from India to New Caledonia, and north to southern Japan (Allen 1985). In Australia, they occur from Shark Bay, WA, around the northern coast to southern Qld. Movement of adult flagfish has not been studied, but is likely to be similar to other lutjanid species, which have restricted along-shore movement. Therefore, the current area-based management strategy for this species is appropriate and regional populations should be treated as separate stocks for fishery management purposes.

Small juveniles aggregate in small groups over sand or mud. On the north-western shelf of WA, adults occur at depths of 20 to 120 m but are most common at depths of 30 to 70 m (Davis and West 1992). The average length of individuals increases with increasing depth. Adults are associated with coral reefs, flat bottoms with coral outcrops, and sponge and sea whip-dominated habitats. They may be solitary or aggregate in small schools.

Flagfish have a very protracted spawning period (virtually all year) on the north-west shelf of WA, but a peak in activity occurs between September and April (Davis and West 1993). They are serial spawners, i.e. spawn numerous batches of eggs. Females are estimated to spawn about 22 times per month, although it is unclear whether this level of intensity is maintained throughout the peak period (Davis and West 1993). Depending on the intensity of activity, a 300 mm female could potentially spawn 4.5-7.6 million eggs per year. Batch fecundity increases with female size. Most spawning


27

activity occurs 3-6 d after new and full moons. Spawning has been observed in the early afternoon, but this may be related to the timing of tides rather than daylight (Davis and West 1993). Size at maturity (50%) of female flagfish is estimated to be 154 mm FL and at 1 y of age (Davis and West 1993).

Flagfish are gonochoristic. That is, they do not undergo sex change. Sexes remain separate throughout life. Males predominate among the larger individuals in the population, although the sex ratio does not change with age (Stephenson and Mant 1999). The trawl catch typically consists of males ranging from 190 to 350 mm and females from 190 to 330 mm LCF. Age ranges from 1 to 14 y for both sexes. Maximum length is 400 mm (Allen 1958). Maximum age is estimated to be 14 y, although the oldest age observed in the fishery is 12 y (Stephenson and Mant 1999). The rate of natural mortality, M, is estimated to be 0.30 (Stephenson and Mant 1999). Similar estimates of longevity and natural mortality (12 y and 0.34 respectively) were observed from populations on the Great Barrier Reef (Newman et al. 2000c).

Red snapper (Lutjanus erythropterus)

Red snapper are widespread throughout the Indo-West Pacific, from Australia and New Guinea, northward to southern Japan and westward to the Gulf of Oman (Allen 1985). In Australia, the distribution ranges from Shark Bay in the west across northern Australia to southern Queensland. Movement of adult red snapper has not been studied, but is likely to be similar to other lutjanid species, which have restricted along-shore movement. Therefore, the current area-based management strategy for this species is appropriate and regional populations should be treated as separate stocks for fishery management purposes.

There is a general offshore movement of juvenile red snapper with increasing age. Small juveniles (> 2.5 cm) occur in shallow waters over muddy substrates (Kailola et al. 1993). Larger juveniles mainly occur in shallow nearshore waters but also occur across the shelf. Adults occur across continental shelf waters to depths of at least 100 m (Kailola et al. 1993). They are associated with shoals, rubble, corals, large epibenthos, hard or soft substrates and offshore reefs. On the north-western shelf of WA, they are often associated with sponge and gorgonian habitats and are often found schooling with L. malabaricus (scarlet sea perch) (Kailola et al. 1993).

Red snapper attain lengths of approximately 64 cm FL and ages of at least 32 y (Newman et al. 2000b).

Red snapper have an extended spawning period from spring to autumn. The estimated length-at-maturity for red snappers from the Great Barrier Reef was estimated to be 46.8 cm by McPherson et al. (1992). The rate of natural mortality, M, is estimated to be 0.15 (Newman et al. 2000b).

Goldband snapper (Pristipomoides multidens) are distributed throughout the Indo-Pacific region from Samoa to the Red Sea, and from Australia to southern Japan (Kailola et al. 1993). In Australia, they occur from Cape Pasley, WA (34oS lat) across the northern coast to Moruya NSW. Within WA, commercial quantities are taken only from Shark Bay (25oS lat) northwards (Newman et al. 2001, Newman and Dunk 2003).


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Stable isotope ratio analysis of the sagittal otolith carbonate from assemblages of goldband snapper from waters off northern and western Australia revealed location-specific signatures and indicated that fish from all sites sampled within Australia were different (Newman et al. 2000c). Therefore the sampled populations comprise separate stocks for many of the purposes of fisheries management. Genetic studies have revealed that there is some gene flow among Australian populations of goldband snapper (Ovenden et al. 2002). Adults occur in continental shelf waters in depths of 60-245 m, in association with offshore reefs, shoals, and areas of hard flat bottom with occasional benthos or vertical relief (Newman et al. 2001). Juveniles have been obtained from uniform sedimentary habitat with no relief. Juveniles and adults do not co-occur over the same habitat types. No cross-shelf movements are known, although adults may feed over a range of depths. They feed on the bottom and in the water column, consuming fish, crustaceans, gastropods, squid and salps (Allen 1985). The adults often form large schools. Goldband snapper are gonochoristic (sexes are separate throughout life) and spawn in the NDSMF from January to April with a peak in March (Newman et al. 2001). They are multiple spawners, within a multiple male: multiple female spawning system. The length at maturity of goldband snapper was estimated to be 55.2 cm TL for females and 54.9 cm TL for males, corresponding to a mean age at maturity, of 8.2 years for females and 8.0 years for males. Goldband snapper reach a maximum total length of 90 cm, although the maximum length observed in the NDSMF is 81 cm (Allen 1985, Newman et al. 2001). A maximum age of 30 y has been observed in the NDSMF (Newman and Dunk 2003). The rate of natural mortality is estimated to be in the range 0.10-0.14 (Newman and Dunk 2003). 2.7.1.2 SERRANIDAE (TRIBE : EPINEPHALINAE) Rankin cod (Epinephalis multinotatus)

In the Indo-Pacific region, there are 11 genera and 110 species of epinepheline serranids (Leis and Carson-Ewart 2000).

Rankin cod occur in the Indian Ocean, from the Persian Gulf to Madagascar and to Australia. In Australia, they are found from Shark Bay north to Darwin. The Western Australian population is considered distinct from other Indian Ocean localities based on colour pattern and scale counts (Heemstra and Randell 1993). The eggs of Epinephelus spp are pelagic (Leis and Carson-Ewart 2000).

Johnson et al. (1993) found no abrupt genetic differentiation of populations between areas sampled in the north-west region of Australia but observed a cline across the range of the study. The cline is consistent with the possibility of limited larval dispersal. Ratios of oxygen and carbon stable isotopes in the otoliths of adults suggest some mixing of populations between Pilbara and Ningaloo regions and between eastern and western areas of the Pilbara (Stephenson et al. 2001). Overall, the data suggest limited larval dispersal and limited adult movement. Hence, the current area-based management strategy for this species is appropriate and regional populations should be treated as separate stocks for fishery management purposes.


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Juveniles occur on inshore reefs. Adults typically occur in deeper waters to a depth of at least 90 m. Rankin cod may occur solitary or in small groups.

Rankin cod spawn from August to October. Immature fish are rare in the fishery, but limited data suggest that 50% of females are mature at age 2.2 y and at 391 mm FL.

Rankin cod are protogynous hermaphrodites, i.e. they change sex from female to male. Males predominate among the larger individuals in the population. Sex change is estimated to have occurred in 50% of females by 626 mm LCF (Stephenson and Mant 1999). Fish in the trawl catch typically range in length from 400-700 mm (female) and 560-740 mm FL (male), and range in age from 1-14 y (female) and 5-20 y (male). Maximum length is approximately 100 cm (Heemstra and Randell 1993). Maximum age is estimated to be 23 y, although the oldest age observed in the fishery is 19 y. The rate of natural mortality, M, is estimated to be 0.18 (Stephenson and Mant 1999).

2.7.1.3 LETHRINIDAE

There are 5 genera and 39 species of lethrinids in the Indo-Pacific region (Leis and Carson-Ewart 2000). They are commonly known as emperors. Juveniles of lethrinids typically occur in shallow inshore habitats such as seagrasses (Kailola et al. 1993). Fish move deeper with increasing age. Larger lethrinids are strongly habitat dependant, tending to aggregate on small patches of suitable habitat that can be fished down rapidly (Moran et al. 1993). Lethrinids are carnivorous bottom feeders. Eggs and larvae are pelagic. Blue-spot emperor (Lethrinus hutchinsi, formerly misidentified as L. choerorynchus)

Blue-spot emperor (also known as lesser spangled emperor) are apparently restricted to Western Australia from around Exmouth Gulf extending north to Darwin (Carpenter and Niem 2001).

Populations of blue-spot emperor in WA are genetically similar, probably due to the dispersal of pelagic larvae (Johnson et al. 1993, Moran et al. 1993). However, they function as discrete populations because of very limited movement by adults (Moran et al. 1993). Hence, the current area-based management strategy for this species is appropriate and regional populations should be treated as separate stocks for fishery management purposes.

Adults occur in shelf waters to depths of at least 80 m. They are associated with coral reef or lagoon areas over substrates of hard coral, gravel, sand or rubble. They can also be associated with sponge and gorgonian dominated habitats, and can occur in clear or turbid waters.

There is limited data on reproduction of blue-spot emperor. The spawning period is short and the timing of spawning varies among regions. In the Pilbara, spawning occurs in September (Stephenson and Mant 1999). The size at matur ity (50%) of females is estimated to be approximately 1.8 y of age and 240 mm FL. This is equivalent to 274 mm TL, which is slightly lower than the minimum legal length for this species in WA of 280 mm TL.


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It is not known whether blue-spot emperors are protogynous hermaphrodites. Males predominate among the larger individuals in the population, but there are no age related differences in sex ratio (Stephenson and Mant 1999). Males in the trawl fishery catch typically range from 240 to 350 mm and females range from 240 to 330 mm FL. Age typically ranges from 2 to 12 y for both sexes. The maximum age of blue-spot emperor is estimated to be 14 y, although the oldest age observed in fishery is 12 y. The rate of natural mortality, M, is estimated to be 0.30 (Stephenson and Mant 1999).

Spangled emperor (Lethrinus nebulosus) are distributed from east Africa and the Red Sea to Samoa (Randall et al. 1990). In Australia, they are distributed from Rottnest Island, WA, across the northern coast to northern NSW (Kailola et al. 1993). Populations of spangled emperor in WA are genetically similar, probably as a result of the dispersal of pelagic larvae (Johnson et al. 1993, Moran et al. 1993). However, they function as discrete populations because of limited movement by adults. Analyses of otolith microchemistry suggest movement of adults is restricted to a few 100 km and tagged fish have dispersed less than 80 nm over 3 y (Moran et al. 1993). Hence, the current area-based management strategy for this species is appropriate and regional populations should be treated as separate stocks for fishery management purposes. Juveniles may form schools. Adults often form schools over sand or rubble (Randall et al 1990). The diet includes bivalve and gastropod molluscs, and sand dollars (Kailola et al. 1993). Spangled emperor spawn from October to March, with some variation in the timing of spawning among years and among regions (Moran et al. 1993). Maturity is reached at approximately 38 cm FL (Moran et al. 1993). This is similar to the legal minimum length in WA of 410 mm TL (= 367 mm FL). Spangled emperor may be a protogynous hermaphrodite. However, if a sex change occurs, it probably takes place in young fish prior to reaching an age when they are targeted by the fishery (Moran et al. 1993). Spangled emperor reach a maximum length at least 86 cm TL and a maximum age of 27 y (Kailola et al. 1993, Moran et al. 1993). Natural mortality, M, is estimated to be 0.155 (Moran et al. 1993). The age structure of lightly exp loited populations suggests variable rates of annual recruitment of spangled emperor (Moran et al. 1993).

2.7.1.4 NEMIPTERIDAE Nemipterids occur only in the Indo-Pacific region. There are 5 genera and 65 species (Leis and Carson-Ewart 2000). Nemipterids are small to moderate sized fishes, generally associated with soft bottoms. They are commonly known as threadfin breams, whiptail breams, monocle breams and coral breams. Rosy threadfin bream (Nemipterus furcosus)

Rosy threadfin bream occur in the western Pacific from southern Japan to north-eastern Australia and in the eastern Indian Oceans including the Gulf of Mannar, Sri


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Lanka, Andaman Sea, Strait of Malacca and north-western Australia (Carpenter and Niem 2001). In Australia, they are found from Exmouth north across northern Australia to southern Queensland. They are found in coastal and offshore waters to 200m. They are demersal and occur over sand or mud bottoms (Kailola et al. 1993). The diet includes small fish, cephalopods, crustaceans and polychaetes. They spawn pelagic eggs (Leis and Carson-Ewart 2000).

There is some evidence that rosy threadfin bream are sequential hermaphrodites, i.e. changing sex from female to male (Young and Martin 1985). Males predominate among the larger individuals in the population, but there are no sex related differences in the age distribution (Stephenson and Mant 1999). Males in the fishery catch typically range from 180 to 320 mm and females range from 180 to 310 mm FL. Ages typically range from 0 to 9 y fo r both sexes. Maximum length is 35 cm. Maximum age is estimated to be 12 y, although the oldest age observed in fishery is 10 y. The rate of natural mortality, M, is estimated to be 0.35 (Stephenson and Mant 1999).

2.7.1.5 SPARIDAE Sparids occur in temperate and tropical areas. There are approximately 100 species of sparids worldwide (Randall et al. 1990). There are 15 genera and approximately 30 species in the Indo-Pacific region (Leis and Carson-Ewart 2000). Sparids release pelagic eggs. They are commonly known as porgies or seabreams.

Frypan snapper (Argyrops spinifer)

Frypan snapper are widely distributed throughout the Indo-west Pacific from South Africa including the Red Sea and Persian Gulf, to the Indo-Malayan Archipelago to southern Japan and Northern Australia (Carpenter and Niem 2001). In Australia, they are found from Shark Bay in the west across northern Australia to northern New South Wales in the east. Juveniles occur in shallow coastal waters and move deeper with age. Adults are common in shelf waters from 5 to 100 m in depth. The diet includes benthic invertebrates, especially molluscs. They attain a maximum length of at least 65 cm and a maximum age of at least 18 y (El-Sayed et al. 1996). Little else is known about the biology of frypan snapper.

2.7.2 BIOLOGY OF SIGNIFICANT NON-TARGET SPECIES 2.7.2.1 DOLPHINS

Family DELPHINIDAE

Bottlenose dolphins (Tursiops truncates) occur in tropical and temperate regions around the world, mostly in nearshore waters but also offshore. They tend to live in groups of <20 but larger groups of several hundreds are often seen offshore (Jefferson et al. 1993). Some dolphin groups have a limited home range, whereas others are migratory. The home ranges of groups tend to be distinct but occasionally overlap (e.g. Chilvers and Corkeron 2001).


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Females breed every 2-3 years, but will calve again after 1 year if their calf dies. Mother and calf typically remain closely associated for 4-5 years, until weaning occurs (Mann et al. 2000). Dolphins consume fish, squid, cuttlefish, eels, and various types of benthic invertebrates. The consume 6 to 7 kg of prey per day (Harrison and Brayden 1988). Lactating females may be more prone to capture in trawl nets because they have higher energy requirements and are likely to undertake more risky behaviour to obtain food.

During the 2002 Pilbara Fish Trawl Fishery bycatch survey (Stephenson and Chidlow 2003), 10-30 dolphins were observed in the trawl area on each occasion when an individual was caught. Underwater video footage from the survey of dolphins interacting with trawl gear suggested that they are attracted to trawl gear while it is operating because of enhanced feeding opportunities. Dolphins were observed to deliberately attach themselves to the headrope, or position themselves in the pressure wave of the net to conserve energy. Dolphins elsewhere have also been observed to employ complex strategies to obtain food from trawl gear. In NSW, bottlenose dolphins have been observed manipulating the cod end of a prawn trawl on the seabed to remove and consume its contents (Broadhurst 1998). Bottlenose dolphins can remain underwater for approximately 10 minutes. During the recent bycatch survey, they were observed to remain in the trawl net for approximately 6 minutes.

2.7.2.2 TURTLES

The 2002 Pilbara Fish Trawl Fishery Bycatch Survey (hereafter Bycatch Survey) caught only green and loggerhead turtles (Stephenson and Chidlow 2003). However, it is possible that the fishery also occasionally interacts with the other species of turtles that occur on the region.

Marine turtles grow relatively slowly. Age-at-maturity of green and loggerhead turtles is at least 20 to 30 years, but may be considerably older depending on the region (Marquez M. 1990). Females are reproductively active for several decades, although there may be periods of 2-7 years between breeding events for individual females, especially if breeding conditions are poor. Marine turtles typically undertake migrations from feeding grounds to breeding grounds. Migrations may be up to 3000 km, depending on species and region. Marine turtles come ashore to nest on beaches.

Family DERMOCHELYDIDAE

Leatherback turtles (Dermochelys coriacea) occur in tropical and temperate waters throughout the world and has the widest distribution of all marine turtles (Marquez M. 1990). In Australia, large numbers of leatherback turtles feed off the south Queensland and New South Wales coasts and off Western Australia's coast, south of Geraldton. They are less abundant in the tropical waters of the northern Australian continental shelf. Most leatherback turtles living in Australian waters migrate to breed in neighbouring countries, particularly in Java and along the northern coast of Irian Jaya, Papua New Guinea and the Solomon Islands (Marquez M. 1990). No large rookeries have been recorded in Australia. Scattered nesting occurs along the south Queensland coast and along the coast of Arnhem Land.

The leatherback is the largest sea turtle and can reach > 2 m in length. It is thought to be the deepest diving turtle, having been recorded at 1000m. Leatherbacks are pelagic,


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feeding on jellyfish and other soft-bodied pelagic organism. They feed in the open ocean, and generally only occur in coastal waters during the autumn/winter breeding season (Marquez M. 1990). They are generally solitary.

Leatherbacks have a nesting cycle of 2-3 years. Females typically lay 4-5 times per season. The clutch size varies from 46 to 160 eggs (Marquez M. 1990).

The leatherback turtle is listed as vulnerable (EPBC Act 1999). In Western Australia, the leatherback turtle has the status of Specially Protected Fauna.

Family CHELONIIDAE

Loggerhead turtles (Caretta caretta) occur in temperate and tropical waters of the world. They typically feed and breed in coastal and shelf waters, but can also occur in the open ocean. In Australia, they occur on coral reefs, and in bays and estuaries in tropical and warm temperate waters off the coast of Queensland, Northern Territory, Western Australia and New South Wales. There are significant nesting areas in Western Australia, including Muiron Island and Shark Bay. Other nesting areas in Australia occur on the southern Great Barrier Reef and adjacent mainland coastal areas.

Loggerheads tagged in Western Australia have been recaptured in the Northern Territory, Western Australia and Indonesia. Females tagged near south east Queensland rookeries have been recaptured in Indonesia, Papua New Guinea, the Solomon Islands, New Caledonia, the Northern Territory, New South Wales and other parts of Queensland. WA’s breeding population of female loggerhead turtles is estimated at approximately 10,000.

In southeastern loggerhead turtles nest from late October, reaching a peak in late December and finish nesting in late February or early March. Nesting probably occurs at similar times in Western Australia (Preen et al, 1997). Hatchlings emerge from nests from December until April with most hatching from February to early March. Loggerheads have a broad carnivorous diet of pelagic and benthic organisms, including shellfish, crabs, sea urchins and jellyfish (Marquez M. 1990). Adults reach approximately 1.0m in length.

Loggerhead turtles reach sexual maturity at 20-30 years of age. They have a typical nesting cycle of 2-3 years. Females may lay 2-5 times per season. The clutch size varies from 23 to 190 eggs (Marquez M. 1990).

Loggerhead turtles are listed as endangered (EPBC Act 1999). In Western Australia, the loggerhead turtle has the status of Specially Protected Fauna. Research on the east coast suggests that the loggerhead turtle has lost 50-80% of its annual nesting population in the last decade.

Green turtles (Chelonia mydas) occur in seaweed-rich coral reefs and inshore seagrass pastures in tropical and subtropical areas of the Indo-Pacific region. They are typically solitary but may form feeding aggregations in shallow waters with abundant seagrass or algae (Marquez M. 1990). Adults are herbivorous and consume algae and seagrass. Juveniles are carnivorous. Adults reach approximately 1 m in length.

Green turtles nesting along the WA coast migrate from feeding grounds in Indonesia, Queensland, Northern Territory and other regions of Western Australia. Nesting


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occurs from November to February. Females display high nesting site fidelity. Green turtles reach sexual maturity between 20 and 30 years of age. They have a nesting cycle of 1-4 years. Females may lay 2-5 times per season. The clutch size varies from 38 to 195 eggs (Marquez M. 1990).

Green turtles mate in the water. A female can mate with several males and store sperm for successive batches of eggs. Having mated, the males return to their feeding grounds. Meanwhile the females stay in the breeding grounds.

In Australia, there are four major green turtle nesting areas: i) the southern Great Barrier Reef has 13 major rookeries; ii) the northern Great Barrier Reef has 5 major rookeries; iii) the south-eastern Gulf of Carpentaria has 3 major rookeries (large numbers also feed in the south-west of the Gulf); and iv) the north-west shelf has widely spread, major rookeries, including the Lacepede Islands, sites north of Broome, the Barrow and Monte Bello Islands, and the Muiron Islands and North West Cape coast. Small numbers also nest elsewhere in the Indian Ocean.

Green turtles are a food source for Aboriginals and Torres Strait Islanders. Green turtles are listed as vulnerable (EPBC Act 1999).

Hawksbill turtles (Eretmochelys imbricata) are distributed throughout tropical waters of the Indo-west Pacific and the central Atlantic. They occur in coastal and shelf waters. In Australia, they occur in tidal and sub-tidal coral and rocky reef habitats, extending into warm temperate areas as far south as northern New South Wales. Feeding areas extend along the east coast of Australia, including the Great Barrier Reef, and also include the Torres Strait, the Northern Territory and Western Australia, possibly as far south as Shark Bay.

There are two major breeding areas in Australia: i) the northern Great Barrier Reef, Torres Strait and northeastern Arnhem Land, and ii) the northwest shelf. Several rookeries occur within each area. On the northwest shelf, rookeries include the Rosemary and Varanus Islands. In Australia, hawksbill turtles mainly breed in spring or summer (Marquez M. 1990).

Hawksbill turtles have a typical nesting cycle of 2-3 years. Females may lay 5 or more times per season. The clutch size varies from approximately 50 to 200 eggs (Marquez M. 1990).

Hawksbill turtles forage among corals and consume sponges, algae, seagrasses, soft corals and shellfish. They attain a length of 90cm. The Hawksbill's has a thick carapace was sought after in the manufacture of 'tortoiseshell' products. However, international trade in turtle products is now prohibited. The flesh is not widely eaten. Hawksbill turtles are listed as vulnerable (EPBC Act 1999).

Olive (Pacific) Ridley Turtles (Lepidochelys olivacea) have a worldwide tropical and subtropical distribution, including northern Australia. They occur in shallow, protected waters, especially in soft-bottomed habitats. In Australia, they occur from southern Queensland northwards to Torres Strait, the Gulf of Papua, the Gulf of Carpentaria, the Arafura Sea and to the Joseph Bonaparte Gulf in Western Australia (Marquez M. 1990). They also occasionally occur in NSW. No large rookeries of olive ridley turtles are known from Australia, although nesting occurs in low numbers along the Gulf coast of Queensland.


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Nesting typically occurs in summer and autumn, but may also occur in spring, depending on region (Marquez M. 1990). They migrate in continental shelf waters and feed in shallow waters (Marquez M. 1990).

Olive Ridley Turtles are the smallest of the marine turtles, attaining lengths < 1 m. They mainly consume shellfish and crustaceans. Olive Ridley Turtles are listed as endangered (EPBC Act).

Flatback turtles (Natator depressus) have a very restricted distribution. They occur in the northern coastal regions of Australia, extending as far south as the Tropic of Capricorn, and also on the Indonesian archipelago and the Papua New Guinea coast. They appear to be restricted to coastal and continental shelf waters and typically occur in shallow, soft-bottom habitats away from reefs (Marquez M. 1990).

All known breeding sites of flatback turtles occur in Australia. They nest on the mainland and inshore islands of the Great Barrier Reef, and the Kimberley and Pilbara regions of Western Australia (north of Port Hedland), and in the Torres Strait. Nesting can occur all year and the peak in nesting activity occurs at different times in each region.

Flatback turtles are small and attain lengths of < 1 m. They are carnivorous, feeding mostly on soft bodied prey such as sea cucumbers, soft corals and jellyfish. They are listed as vulnerable (EPBC Act 1999).

2.7.2.3 SEA SNAKES Family HYDROPHIIDAE

Hydrophiidae, or true sea snakes, are the only species of sea snakes with breeding populations in Australian waters. These species are listed under the EPBC Act. There are a total of 54 species of Hydrophiids, 32 of which are found in Australian waters. Hydrophiids are viviparous (live young) and do not return to land to breed but may migrate to inshore or estuarine waters to give birth (Ward 2000). Brood sizes are generally <10 eggs (Heatwole 1999). Fecund ity increases with female body size. Little is known about the status of populations of sea snakes in Australian waters, or about the basic ecology, movement patterns, life history strategies, reproductive biology and population genetics of most species of sea snakes.

A total 19 species of sea snakes are recorded as caught by fish trawling in northern Australian shelf waters (Ward 1996a). Of these, Hydrophis ornatus, H. elegans and Aipysurus laevis are the most common. A total 14 species of sea snakes are recorded as caught by prawn trawling in northern Australian shelf waters (Ward 1996b, 2000). Of these, Hydrophis elegans, H. ornatus, Disteira major, Aipysurus eydousii and Lapemis hardwickii are the most common.

Differences in the composition of prawn and fish trawl catches partly reflects the depth and habitat preferences of each sea snake species. In general, sea snakes are most common in shallow shelf waters (i.e. < 75 m), but the distribution of each species varies with depth. Prawn trawlers catch an order of magnitude more sea snakes than fish trawlers because prawn trawling occurs closer to shore.

In the 2002 Bycatch Survey (Stephenson and Chidlow 2003), only Hydrophis elegans was caught. This species reaches 200 cm in length.


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2.7.2.4 SEAHORSES AND PIPEFISH Various aspects of the life history of seahorses make them susceptible to overfishing: Males brood small batches of eggs and release of live young; which limits reproductive potential. Adults have low mobility and small home ranges, which restrict recolonisation of depleted areas. The strict monogamy between mating pairs means that social structure is easily disrupted and the sparse distribution of adults means that lost partners are not quickly replaced. The rate of natural mortality is relatively low. Many aspects of seahorse biology, such as growth rates, longevity and juvenile dispersal remain unstudied.

The biology of pipefish is not well understood. In general, however, pipefishes are like seahorses in having patchy distributions, relatively low dispersal, low fecundity, and lengthy parental care.

Results of the 2002 Bycatch Survey suggested that the fishery catches two species of sygnathids (Stephenson and Chidlow 2003). The survey caught small quantities of Hippocampus histrix and larger quantities of Solegnathus hardwickii.

Family SYGNATHIDAE

Spiny seahorses (Hippocampus histrix), also known as Thorny seahorses, occur throughout the Indo-Pacific, from Africa to Hawaii and Tahiti, north to Japan and south to New Caledonia (Russell and Houston 1989). They are associated with shallow sheltered reefs, clumps of algae, sponges, sea-squirts and seagrass beds to depths of 82 m. Large adults occur pelagically and are probably associated with drifting debris (Lourie et al. 1999). Spiny seahorses reach maximum length of 17 cm TL (Randall 1995).

This name has been used for at least four distinct species. However, the true H. histrix is a very distinctive species with one of the largest distributions of any seahorse (Lourie et al. 1999).

The use of spiny seahorses in traditional Chinese medicine is limited but increasing with the rise in patent medicines (Lourie et al. 1999). They are not common in the aquarium trade.

Pallid pipefish (Solegnathus hardwickii), also known as Hardwicke's pipefish, are not true pipefish, but are in fact 'pipehorses' (which includes the genera Solegnathus and Acentronura). Pallid pipefish occur in tropical and subtropical areas of the Indo-Pacific, from Mauritius to the South China Sea, north to southern Japan, and south to northern Australia. Within Australia, they occur in New South Wales, the Northern Territory, Queensland and Western Australia (Paxton et al. 1989). In WA, they are found north of Onslow. They are demersal across the continental shelf at depths up to 180 m, but are mostly known from depths < 100 m. Populations are very patchily distributed, possibly reflecting the distribution of suitable habitat (Pogonowski et al. 2002).

Male pallid pipefish undertake egg brooding, possibly from 296 mm in length (Dawson 1985). Pallid pipefish attain a maximum length of 510 mm TL.

Members of the genus Solegnathus are the most valuable syngnathids in traditional Chinese medicine. They are listed as vulnerable on the 2002 IUCN Red List and


37

listed under the EPBC Act. However, there is no evidence of population decline in this species (Pogonowski et al. 2002).

2.7.2.5 NON-RETAINED SCALEFISH Family SYNODONTIDAE

There are 4 genera and 50 species of lizardfish worldwide. In the Indo-Pacific region, there are 20-30 species (Smith and Heemstra 1986, Randall et al. 1990). They occur at depths ranging from the shore to 4100 m, although most species are found at depths of <1000 m (Leis and Carson-Ewart 2000). Lizardfish are bottom dwellers on coral reefs and soft bottoms, and are able to bury themselves in sediment. They are voracious carnivores, darting up from the sediment to capture prey. Most species are relatively small, reaching a maximum length of 20-60 cm. Eggs and larvae are pelagic.

Lizardfish are a bycatch of the NPF with an estimated catch of 3650 t per year (Kailola et al. 1993). Prior to 1989, up to 1200 t were retained by Thai and Taiwanese demersal fish trawlers from the NW Shelf, Timor and Arafura Seas. Retained catch rates of up to 60 kg per hour were achieved on the NW shelf and Timor sea. The catch mainly consisted of short- finned lizardfish (Saurida micropectoralis) and checkered lizardfish (S. undosquamis), from depths of 11 to 120 m. Lizardfish are mostly discarded when caught by trawl fisheries, although there is a market for dried S. undosquamis in Taiwan (Kailola et al. 1993). Lizardfish populations across northern Australia have increased in size as a result of seabed modification by trawling (Sainsbury 1987).

Lizardfish comprise the highest component (approximately 26%) by weight of all finfish taxa in the non-retained catch of the Pilbara fish trawl fishery. The 2002 Bycatch Survey (Stephenson and Chidlow 2003) caught a single species of lizardfish, which was common across the depth range of the survey (i.e. 50 to 100 m). The species was not formally identified but, based on external appearance, was probably either Saurida undosquamis or S. tumbil. Each of these species is distributed throughout the Indo-west Pacific region.

At the ESD Risk Rating Workshop for the PFTIMF in December 2002, it was reported that declining in recreational catches of billfish in the Pilbara region had coincided with increasing catches of lizardfish by the trawl fishery (L. Vertigan pers. comm.). However, billfish (e.g. sailfish, marlin) primarily feed on epipelagic fish and rarely consume demersal fish such as lizardfish (Rosas-Alayola et al. 2002). Therefore it is unlikely that any change in the population of lizardfish due to trawling will impact directly on billfish abundance in the region.

Checkered lizardfish (Saurida undosquamis) occur subtropically from 45°N to 40°S. They occur in the Red Sea, Persian Gulf, East Africa to Japan, the Arafura Sea and the Great Barrier Reef. They have also migrated to the eastern Mediterranean via the Suez Canal. They are found over sand or mud bottoms in coastal waters to depths of 290 m. S. undosquamis consume fish, crustaceans and other invertebrates. They are prey items for sharks and larger fishes. S. undosquamis reach a maximum length of 50 cm SL and a maximum age of 7-8 y (Thresher et al. 1986). They mature at approximately 16-17 cm and 1-2 y. Spawning occurs in autumn/winter.


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Saurida undosquamis are of minor commercial importance in some countries. They are generally marketed frozen, sometimes fresh and as fish cakes ('kamaboko') in Japan. The species is probably moderately resilient to overfishing, with a minimum population doubling time estimated at 1.4 - 4.4 years (Fishbase 2003).

Common grinner (Saurida tumbil) are a tropical species distributed from 34°N to 28°S. They occur in the Red Sea, the east coast of Africa, the Persian Gulf, the Arabian Sea, and east to southeast Asia and Australia. They are found on muddy bottoms at depths of 10-60 m. They consume fish, crustaceans and squids. S. tumbil reach a maximum length of 60 cm FL and a maximum age of possibly 7 y. They mature at 25 cm or more.

Saurida tumbil are of commercial importance in some countries and are sold fresh. The species is probably moderately resilient to overfishing, with a minimum population doubling time estimated at 1.4 - 4.4 years (Fishbase 2003).

Family BALISTIDAE

Triggerfish

In the Indo-Pacific region, there are 12 genera and 30 species of triggerfish (Leis and Carson-Ewart 2000). 9 species occur in WA. Most species are associated with coral or rocky reefs. They are mainly solitary in habit (Allen 1997). The diet typically includes hard-shelled items such as molluscs, crabs and echinoderms, but may also include gorgonians, corals, sponges, hydroids and algae. Triggerfish lay demersal eggs that are guarded by one of the parents (Leis and Carson-Ewart 2000). They typically have an extended pelagic juvenile phase.

Triggerfish comprise the second highest component (approximately 15%) by weight of all finfish taxa in the non-retained catch of the Pilbara fish trawl fishery. In the 2002 Bycatch Survey (Stephenson and Chidlow 2003), triggerfish were common across the depth range of the survey (i.e. 50 to 100 m). The catch of triggerfish was mainly Abalistes stellatus, with small numbers of Psuedobalistes fuscus and Sufflamen fraenatus. Each of these species is distributed throughout the Indo-west Pacific region.

The same three triggerfish species are also taken as bycatch by the Northern Demersal Scalefish Fishery. Abalistes sp. is most commonly caught and comprises 1.1% of the total catch (Newman et al. 2001).

Starry triggerfish (Abalistes stellatus) occur in coastal and shelf waters and are associated with a variety of habitats, including coral and rocky reefs and soft sediments (Allen 1997). They attain a length of 60 cm (Fishbase 2003).

Yellow-spotted triggerfish (Psuedobalistes fuscus) are found in clear shallow lagoons and seaward reefs to 50 m. Sandy areas adjacent to reefs are preferred. They feed on sea urchins, crustaceans, molluscs, dead fish, tunicates or corals. They attain a length of 55 cm. Spawning occurs in summer. The species is of commercial fishery importance in some countries, and is marketed fresh or dried. It is also collected for aquariums (Fishbase 2003).

Brown triggerfish (Sufflamen fraenatus) occur from 30°N to 32°S. Adults are found over sand and rubble patches of seaward reefs, from depths of 8 to 186 m. Juveniles are associated with shallow vegetated areas (Smith and Heemstra 1986). Adults attain


39

a length of approximately 40 cm. They feed on echinoids, fishes, molluscs, tunicates, crustaceans, algae, polychaete worms, foraminiferans and detritus. The species of minor commercial fishery importance in some countries and is collected for aquariums (Fishbase 2003).

2.7.2.6 MORAY EELS Family MURAENIDAE

The largest genus within the family Muraenidae is Gymnothorax, with 22 species occurring in Western Australia (Allen 1985). Moray eels are typically associated with structurally complex habitats such as reefs, where they hide in crevices. They have a lengthy pelagic larval phase (months) that allows each species to disperse widely. Eels initially mature as males and change later to females. Eels are carnivorous, mainly consuming fish and occasionally octopi and crustaceans. Most species forage during the day.

In the 2002 Bycatch Survey (Stephenson and Chidlow 2003), the catch rate of moray eels was similar at all depths in the survey (i.e. 50 to 100 m). They were often found attached to pieces coral or sponge. Moray eels were not formally identified during the survey but individuals were of the genus Gymnothorax and, based on external appearance, were probably G. undulatus. G. undulatus (mottled moray) is a common species of eel in the Indo-west Pacific region. It actively hunts at night, and reaches 150 cm in length (Allen 1997, Randall et al. 1990)

2.7.2.6 SHARKS, RAYS AND SAWFISH The trawl fishery catches numerous species of sharks, many of which are discarded because of they are unmarketable. The fishery also catches several species of rays, all of which are discarded. Of the retained sharks, sandbar shark (locally also known as "thickskin shark") has been identified as most vulnerable to overfishing. This vulnerability arises because of a K-selected life history (long- lived, slow to reproduce) and the fact that various fisheries in the region target it. Sandbar shark is currently the subject of a FRDC-funded research project in Western Australia.

Family CARCHARHINIDAE

There are 12 genera and 48 species of whaler sharks (family Carcharhindae) worldwide (Randell et al. 1990). This family includes the sandbar shark, which is the main species of shark caught commercially in the Pilbara region, by the fish trawl fishery and by dedicated local shark fisheries.

The sandbar shark (Carcharhinus plumbeus) is a medium sized, grey–brown carcharhinid shark, which occurs in tropical and temperate coastal waters in most of the world's oceans. In Australia, sandbar sharks occur off the coast of Queensland, Northern Territory and Western Australia (Last and Stevens 1994) and possibly South Australia. They are most commonly found on, or just above the seabed and occasionally at the surface, from the intertidal zone to depths of 200m (Springer 1960).


40

On the east coast of the United States, juvenile sandbar sharks are born in sheltered bays and estuaries, These shallow, sheltered areas are used by juveniles as summer nursery grounds for several years, whilst in winter they migrate offshore to warmer Gulf-Stream waters. Sub-adult and adult sharks undertake an annual northerly migration during summer in the Western North Atlantic, returning to warmer southern waters during the winter. Adults may migrate in schools.

Although well studied in the north-western Atlantic, little is known about the biology of sandbar sharks in Australian waters. In general, the species probably exhibits life history attributes that are characteristic of the more K-selected carcharhinid species. Sandbar sharks mate and give birth in warmer months. Reproduction is viviparous. The gestation period is 9-12 months, and females give birth every second year or less often. Litter size increases with female size and may vary from 1 to 14 pups, with an average of 6 (Springer 1960). In Western Australia, pupping thought to occur between North West Cape and Albany during summer and autumn (McAuley, unpublished data). Locally, size at birth is between 40 cm and 50 cm TL, although it has been reported to be up to 75 cm TL elsewhere (Compagno 1984).

In US waters, this species has been reported as taking between 15 and 30 years to reach sexual maturity (Casey and Natanson 1992; Sminkey and Musick 1995). Size at maturity is 131-178 cm (males) and 144-183 cm (females). Sandbar sharks reach a maximum length of between 245 cm and 300 cm TL (Last and Stevens 1994; Compagno 1984) and may live for up to 50 years. Their diet consists of small bottom fish, which are usually take live, and some crustaceans and molluscs. Adults are thought to have few predators but other sharks may take juveniles.

Family PRISTIDAE

There are between five and seven species of sawfish in the world. Five species occur in Australia, and four within the Pilbara region. Sawfish are typically found in estuaries and freshwater in Queensland, the Northern Territory and Western Australia. They move between fresh and salt water easily.

The 2002 bycatch survey of the Pilbara Fish Trawl Fishery (Stephenson and Chidlow 2003) caught only green and narrow sawfish. It is possible that the fishery also occasionally catches freshwater and dwarf sawfish, which may occur in the region, but these interactions are probably rare (R. McAuley pers. comm.).

Sawfish mainly feed on crabs, shrimps and other bottom dwelling invertebrates. Some species feed on slow moving schools of demersal fish. They locate food using their highly sensitive 'saw' that can detect the movement of buried prey. The 'saw' is also used to disable prey and as a weapon when threatened.

Little is known about the reproductive biology of sawfish. They probably mate in alternate years and have an average litter size of about eight pups. The pups are born live. Size at birth varies among species.

Narrow sawfish (Anoxypristis cuspidata) are widely distributed throughout the Indo-Pacific, from the Red Sea to Australia and north to Japan. They occur in the northern waters of Australia from Eighty Mile Beach (WA), east to Cape York (Qld) and possibly southwards on the east coast (R. McAuley pers. comm.). Their distribution is mainly marine. They are found to depths of at least 40 m, and occasionally occur at depths up to 120 m. They attain lengths of approximately 350 cm. The Narrow


41

sawfish is not listed as a protected species, although the global population is estimated to be at less than 50% of its level 30-50 years ago (Pogonoski et al. 2002). Green sawfish (Pristis zijsron) are widely distributed throughout the Indian Ocean and western Pacific. They are primarily a tropical species. In Australia, they are common from Broome, WA, northwards to southern Qld. On the east coast they occasionally occur as far south as Sydney (NSW) (Last and Stevens 1994). In Western Australia, the distribution extends at least to the Montebello Islands. Juveniles are known from Shark Bay and adults have occasionally been caught as far south as Rottnest Island (R. McAuley pers. comm.). They prefer muddy bottom habitats and will enter estuaries. They attain lengths of at least 500 cm. Both green and narrow sawfish are listed on the IUCN Red List and green sawfish is currently under nomination for listing as endangered under the EPBC Act.

Freshwater sawfish (Pristis microdon) occur throughout the Indo-west Pacific, including northern Australia. They occur in fresh, brackish or marine waters. In Western Australia, they are known from the Fitzroy, Durack and Ord Rivers (Last and Stevens 1994) but are also occasionally encountered in coastal waters, including depths at which the trawl fishery operates (R. McAuley, unpubl. data). They are the largest freshwater fish in Australia, reaching a length of at least 280 cm.

Freshwater sawfish are listed as critically endangered on the IUCN Red List of Threatened Species and listed as vulnerable under the EPBC Act.

Dwarf sawfish (Pristis clavata) occur from Cairns (Qld) across northern Australia to the Kimberley Coast (WA). The distribution outside Australia is uncertain but they may occur elsewhere in the Indo-Pacific (Last and Stevens 1994). They are found in coastal and estuarine habitats, particularly mudflats in the Gulf of Carpentaria. They can be found some distance up rivers, almost into freshwater. They attain a maximum length of at least 140 cm.


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3. METHODOLOGY

3.1 SCOPE This application is based upon the ESD assessment of the PFTIMF. The ESD report was generated by assessing the contribution of the PFTIMF to ESD. This assessment examined the benefits and the costs of the PFTIMF across the major components of ESD (Table 4). In doing so, it will eventually provide a report on the performance of the fishery for each of the relevant ecological, economic, social and governance issues associated with this fishery. Only the criteria required for the “Guidelines for the Ecologically Sustainable Management of Fisheries”, which cover mainly the environmental elements of ESD (outlined below in Table 4) were generated for this application. Table 4 Main National ESD Reporting Framework Components. Nb: Only those ESD components in bold* are reported in this application.

1. Contribution to Ecological Wellbeing 2. Retained Species* 3. Non-Retained Species* 4. General Ecosystem* 5. Contribution to Human Wellbeing 6. Indigenous Community Issues 7. Community Issues 8. National Social and economic Issues 9. Ability to Achieve 10. Governance* 11. Impact of the environment on the fishery

3.2 OVERVIEW There were four steps involved in completing the ESD report for the PFTIMF. It was based upon using the National ESD Reporting Framework, which is outlined in detail in the WA ESD policy paper (Fletcher, 2002) and in the “How to Guide” (Fletcher et al., 2002) located on the website (www.fisheries-esd.com): 1. The issues that needed to be addressed for the fishery were determined at a

stakeholder workshop for the fishery. This process was facilitated by adapting the set of “Generic ESD Component Trees” into a set of trees specific to the PFTIMF.

2. A risk assessment/prioritisation process was completed that objectively determined, which of these identified issues was of sufficient significance to warrant specific management actions and hence a report on performance. The justifications for assigning low priority or low risk however were also recorded.

3. An assessment of the performance for each of the issues of sufficient risk to require specific management actions was completed using a standard set of report


43

headings where operational objectives, indicators and performance measures, management responses etc were specified.

4. An overview assessment of the fishery was completed including an action plan for activities that will need to be undertaken to enable acceptable levels of performance to continue or, where necessary, improve the performance of the fishery.

Report on Justification for Risk

Rating Only

Low Risk/Priority

Develop Objectives Indicators

Performance limits Report Current Status

> Low Risk/Priority

Risk Assessment

ESD Component Trees

(issues identified) PLUS

GENERAL BACKGROUND INFORMATION

=

ESD REPORT

Use Data for other

purposes

For example,

Applications to DEH

Figure 6. Summary of the ESD reporting framework processes.

3.3 ISSUE IDENTIFICATION (COMPONENT TREES) The National ESD Reporting Framework has eight major components, which fall into three categories of the “contributions to ecological wellbeing”, “contributions to human wellbeing” and the “ability to achieve the objectives” (Table 4). Each of the major components is broken down into more specific sub-components for which ultimately operational objectives can be developed. To maximize the consistency of the approach amongst different fisheries, common issues within each of the components were identified by the SCFA and ESD reference groups within each of the major component areas and arranged into a series of “generic” component trees (See Fletcher (2002) and the www.fisheries-esd.com web site for a full description). These generic trees were used as the starting point for identifying the issues. These trees were subsequently adapted into trees specific to the PFTIMF by expanding (splitting) or contracting (removing/lumping) the number of sub-components as required (see Figure 7).


44

Sub-sub-subComponent

Sub-sub-subComponent

Sub-Sub-Component

Sub-Component 1

Sub-Sub-Component

Sub-Component 2 Sub-Component 3

Component

Figure 7. Example of a component tree structure.

3.4 RISK ASSESSMENT/PRIORITISATION PROCESS After the components/issues were identified, a process to prioritise each of these needs was completed using a formal risk assessment process. The risk assessment framework that was applied at the internal workshop was consistent with the Australian Standard AS/NZS 4360:1999 Risk Management, concentrating on the risk assessment components. The general Risk Assessment process is well documented but in summary, it considers the range of potential consequences of an issue/activity and how likely those consequences are to occur. The combination of the level of consequence and the likelihood is used to produce an estimated level of risk associated with the particular hazardous event/issue in question. An estimate of the consequence level for each issue was made by the group at this internal workshop. This level was from 0-5, with 0 being negligible and 5 being catastrophic/irreversible (see Appendix 2 for details of consequence tables). This assessment was based upon the combined judgments of the participants at the workshop, who collectively had considerable expertise in the areas examined. The level of consequence was determined at the appropriate scale for the issue. Thus for target species the consequence of the PFTIMF was based at the population not at the individual level. Obviously catching one fish is always catastrophic for the individual but not always for the population. Similarly, when assessing possible ecosystem impacts this was done at the level of the whole ecosystem or at least in terms of the entire extent of the habitat, not at the level of an individual patch or individuals of non-target species. The likelihood of a consequence occurring was assigned to one of six levels from remote to likely. In doing so, again it was considered the likelihood of the “hazardous” event (consequence) actually occurring based upon collective wisdom, which included an understanding of the scale of impact required. From these two figures (consequence and likelihood), the overall risk value, which is the mathematical product of the consequence and likelihood levels (Risk = Consequence x Likelihood), was calculated. Finally, each issue was assigned a Risk


45

Ranking within one of five categories: High, Moderate, Acceptable, Low and Negligible based on the risk value (see Table 5). Table 5 Risk ranking definitions.

RISK Rank

Likely Management Response Reporting

Negligible 0 Nil Short Justification Only

Low 1 None Specific Full Justification needed

Moderate

2

Specific Management Needed Full Performance Report

High

3

Possible increases to management activities needed

Full Performance Report

Extreme

4

Likely additional management activities needed

Full Performance Report

In general, only the issues of sufficient risk (Moderate, High & Extreme), - those that require specific management actions need to have a full performance reports completed. Nonetheless, the rationale for classifying issues as low risk or even negligible were also documented and formed part of the ESD report. This allows all stakeholders and interested parties to see why issues were accorded these ratings. This process is summarized in Figure 6 (above). It is important to note that the Risk Assessment involves the completion of reports that contain the completed justifications for the scores generated. Thus, the scores determined within the meeting by themselves are insufficient.

3.5 COMPONENT REPORTS Only the issues of sufficient risk or priority that require specific management actions have a full performance report completed (which form section 5 of this application). Nonetheless, the rationale for classifying issues as low risk/priority were also documented and forms part of the report so that stakeholders can see where all the identified issues have finished. For each of the lowest level sub-components (assessed as being of sufficient risk/priority to address), a detailed assessment of performance is generated. The SCFA Working Group in conjunction with the ESD Reference Group agreed upon a set of 10 standard headings each of which need to be addressed (Table 6). Added to this list a further heading, “Rationale for Inclusion”, has been added. This specific heading allows the issues raised within the risk assessment process to be explicitly


46

recorded. A full description of each of these headings is located in the WA ESD policy (Fletcher, 2002), which is available on the WA Fisheries website. Table 6 The National ESD reporting framework headings used in this report. 1. Rationale for Inclusion 2. Operational Objective (+ justification) 3. Indicator 4. Performance Measure (+ justification) 5. Data Requirements 6. Data Availability 7. Evaluation 8. Robustness 9. Fisheries Management Response -Current -Future -Actions if Performance limit is exceeded 10. Comments and Action 11. External Drivers The completion of these component reports was initiated after the stakeholder workshop for the PFTIMF. Progress towards completing these reports was subsequently made by a variety of Departmental staff. The draft application was sent to DEH and stakeholders including industry members and industry groups for review. This final application was generated after the review process.


47

4. ASSESSMENT OF THE PFTIMF MANAGEMENT REGIME AGAINST THE AUSTRALIAN GOVERNMENT GUIDELINES FOR ASSESSING THE ECOLOGICALLY SUSTAINABLE MANAGEMENT OF FISHERIES

4.1 GENERAL REQUIREMENTS OF THE GUIDELINES The management arrangements must be: Documented, publicly available and transparent; As per the FRMA “the Executive Director is to cause a copy of every order, regulation and management plan in force under this Act-

To be kept at the head office of the Department; and To be available for inspection free of charge by members of the public at that office during normal office hours.”

In addition to the legislative requirements, the current management regime, as documented in the formal set of management regulations, can be purchased by interested parties from the State Law Publisher or viewed on their website. Of more relevance is that any discussion papers and proposals for modifications to these management arrangements are distributed widely to stakeholder groups automatically and other interested individuals by request in hard copy format. Where appropriate, they are now also available from the Departmental web site www.fish.wa.gov.au. Once completed, the full ESD Report for the PFTIMF will be made publicly available via publication and electronically from the Departmental website. This will provide increased transparency through explicitly stating objectives, indicators, performance measures, management arrangements for each issue and how the fishery is currently performing against these criteria. As a result, the Department of Fisheries is meeting this guideline. Developed through a consultative process providing opportunity to all interested and affected parties, in cluding the general public; The Department of Fisheries is meeting this guideline through a variety of consultative processes. S64 and S65 of the FRMA define the requirement for procedures that must be undertaken before determining or amending all management plans. More specifically, the current management arrangements for PFTIMF were developed through formal consultation with the industry.


48

The Department of Fisheries arranges annual meetings with industry members regarding the fishery. These meetings review data from the past seasons harvest and discuss management arrangements. In addition, a stakeholder workshop was held to seek outside involvement in the development of the ESD report. This workshop was attended by industry members, industry representative groups, non-government environmental organisations, scientific researchers and other state government agencies as well as a representative from DEH. The information that was collected through the workshop has been incorporated within this report. Ensure that a range of expertise and community interest are involved in individual fishery management committees and during the stock assessment process; The range of expertise and community interests that have been involved in the process of determining management and reviewing stock assessments is extensive. The groups that have been involved in the generation and review of the information contained in this application include:

• Department of Fisheries, WA; • Western Australian Fishing Industry Council (WAFIC); • Department of Environment, WA; • Department of Conservation and Land Management; • DEH; • The trawling industry; • The line industry; • The Pilbara Trap licensees; • Recfishwest; • Pilbara Regional Recreational Fishing Advisory Committee; • Conservation Council of WA; • Aboriginal Lands Trust; • CSIRO; and • Marine and Coastal Community Network.

As a result, the Department of Fisheries is meeting this objective. See Section 5.4.2.1 Consultation for more information. Be strategic, containing objectives and performa nce criteria by which the effectiveness of the management arrangements are measured; The Department of Fisheries is achieving this guideline through the ESD Component Reports. These reports (see Section 5 Performance Reports) contain the available objectives, indicators and performance measures for measuring and assessing the effectiveness of the management arrangements for the PFTIMF. For some components, the objectives, indicators and performance measures are well established and the data are available to demonstrate levels of performance over time. For other components, the objectives, indicators and performance measures have only just been developed and/or the necessary data collection is only just being initiated. The status


49

of this information is documented within each of the individual component reports within the National ESD Reporting Framework in Section 5.1-5.4. Be capable of controlling the level of harvest in the fishery using input and/or output controls; The FRMA and specifically the interim management plan for the fishery provide the legislative ability to control the level of harvest within this fishery. This is achieved through the use of a sophisticated and effective combination of input controls based upon gear restrictions, area closures and total and area effort limitations. As a result, the Department of Fisheries is meeting this guideline. See Sections 5.4.1.1 and 5.4.1.2 for more information. Contain the means of enforcing critical aspects of the management arrangements; The Department of Fisheries employs operational staff to ensure compliance with the critical aspects of the management arrangements for the PFTIMF. This includes at-sea patrols to ensure restrictions on gear and other operational rules are being adhered as well as inspections of catches at the point of landing and processing factories. In 1998, VMS was introduced into the fishery. If a breach is detected with VMS it is reported to the compliance officers and management officers, who then investigate the offence. If it is warranted, a prosecution brief is formed. If the breach is of a minor provision, then a warning is given. Sea patrols and radar watches are also conducted on a random basis through the seasons. Compliance operations are mainly focussed on maintaining the integrity of the areas within the fisheries. The compliance staff also conducts annual licence and gear inspections both at sea and at port and subsequently, breaches being very rare. Given the value of licences, fishers themselves are also a source of information on illegal activities. A full summary of these compliance activities and their effectiveness is provided in Section 5.4.1.3. Through the combination of having employed operational staff as well as a good dialog with the fishers, the Department is meeting this guideline. Provide for the periodic review of the performance of the fishery management arrangements and the management strategies, objectives and criteria; There is an annual review of the performance of the major aspects for the fishery at the annual industry meeting which is reported in the “State of the Fisheries” report. In addition, the Department is meeting this guideline through the five-year review of this ESD document. The State of the Fisheries Report is updated and published each year including periodic reviews by the Office of the Auditor General (OAG). It forms an essential supplement to the Department’s Annual Report to the WA Parliament with the latest


50

version located on the Departmental website www.fish.wa.gov.au. See Section 5.4.3.1 Assessments and Reviews for more information. The ESD Component Reports contain a comprehensive performance evaluation of the fishery based upon the framework described in the ESD policy (Fletcher, 2002). The reports include the development of objectives, indicators and performance measures for all aspects of the fishery and status reports for those components that are not subject to annual assessment. The Department intends to complete and review externally this full assessment, including examination of the validity of the objectives and performance measures every five years. Be capable of assessing, monitoring and avoiding, remedying or mitigating any adverse impacts on the wider marin e ecosystem in which the target species lives and the fishery operates; and The Department of Fisheries is meeting this guideline through the development of this report. Capabilities for the assessment, monitoring and avoidance, remedying or mitigating any adverse impacts on the wider marine ecosystem are documented in the “General Environment” Section 5.3. This has been completed through a formal risk assessment analysis of the issues and, where necessary, the development of suitable monitoring programs. Require compliance with relevant threat abatement plans, recovery plans, the National Policy on Fisheries Bycatch, and bycatch action strategies developed under that policy. The management regime complies with all relevant threat abatement plans for species where there is an interaction and therefore is meeting this guideline. Details are provided in the “non-retained species” section of the ESD report (Section 5.2). In addition, the Department of Fisheries will be developing a Bycatch Action Plan for this fishery based upon the information presented in this application. Furthermore, the Department is organising a Dolphin Expert Panel. This panel will be comprised of stakeholders and experts in the cetacean field. It will look at the current data on trawl interactions with cetaceans and propose a way forward with this issue.


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PRINCIPLE 1 OF THE AUSTRALIAN GOVERNMENT GUIDELINES

OBJECTIVE 1. MAINTAIN VIABLE STOCK LEVEL OF TARGET SPECIES The fishery shall be conducted at catch levels that maintain e cologically viable stock levels at an agreed point or range, with acceptable levels of probability.

Threadfin bream

Flagfish

Frypan snapper

Blue-spot emperor

Short-lived species

Rankin cod

Red emperor

Scarlet perch

Goldband snapper

Red snapper

Spangled emperor

Long-lived species

Primary Species

Elasmobranchs

Bugs

Cephalopods

Other finfish

Shells

By-Product Species

Retained Species

The component tree detailing the retained species for the fishery is shown above. Each of the primary species and by-product species retained by the fishery has been assessed with appropriately detailed reports having been compiled on each of them. As shown above the primary species have been divided into categories; long- lived and short- lived species as monitoring of the fishery is conducted in this manner. A Moderate Risk rating was given to both groups of primary species in the fishery, long- lived and short- lived species thereby requiring full reports (Section 5.1.1.1 and 5.1.1.2). For the by-product species, Elasmobranchs were also given a Moderate Risk rating resulting in a full report being developed (Section 5.1.2.2). The four other categories were all classified as Low Risk (5.1.2.1, 5.1.2.3 and 5.1.2.4). An assessment of the current performance for the PFTIMF demonstrates that all of the fish species are being maintained at acceptable levels to maintain ecologically viable stock levels. Thus, in summary:

• The spawning stocks of the long- lived primary species in the fishery are managed through three indicators; spawning biomass of virgin level for Rankin cod and red emperor (determined by an age-structure model),


52

annual trawl catch of each long- lived target species and catch rate of each long- lived target species.

• Using the indicators described above, two of the major long- lived target species (i.e. Ranking cod and spangled emperor, goldband snapper and red snapper) were below the acceptable performance limits in 2001 and two species (i.e. Rankin cod and spangled emperor) were below performance limits in 2002.

• The spawning stocks of the short- lived primary species in the fishery are managed through three indicators; spawning biomass of blue-spot emperor, annual trawl catch of each short-lived target species and catch rate of each short-lived target species.

• Using the indicators describe above, three of the major short-lived target species (i.e. blue-spot emperor, flagfish and frypan snapper) were below the acceptable performance limits in 2001, and none in 2002.

• The level of capture of other scalefish by this fishery was 767 tonnes in 2002, which is spread across at least 37 taxa of scalefish.

Consistent with these guidelines, the catch rates of the long-lived species triggered a review in 2002. At the review meeting, research advice was that the short- lived species were being harvested sustainably but that effort reduction was required in Area 1 and Area 5. Consequently, the trawl and trap effort was reduced in 2003. The information relevant to this Principle 1 for these species is detailed below. Information Requirements 1.1.1 There is a reliable information collection system in place appropriate to

the scale of the fishery. The level of data collection should be based upon an appropriate mix of fishery independent and dependent research and monitoring.

Data are collected through a combination of fishery independent and fishery dependent systems to monitor the stock abundance within the fished areas. In addition to the statutory CAES logbooks which require licence holders to report or retained catch, the Department collect data from a voluntary skipper’s logbook (completed by all skippers) which provides information on all retained and non-retined species including listed species (dolphins, turtles, sawfish etc). Furthermore, the Department has begun an observer program to validate the catches recorded in both logbooks and the industry are currently trialling on-board digital cameras that record all catch brought to deck. In the longer-term footage from these cameras is expected to act as the primary validation of catches and the observer program will be reduced and simply used as an audit of the digital footage. Section 2.6.1 discussed the recent and current research projects, which have been undertaken for this region. In 1993/94, a mortality experiment (Stephenson and Dunk, 1996) was undertaken to determine the level of fishing effort in the fishery required to ensure sustainable catches. The study determined that red emperor and Rankin cod were over-exploited, while flagfish, lesser spangled emperor and rosy threadfin bream were under-exploited. A subsequent study (Stephenson and Mant 1999) determined age structure and biological characteristics for red emperor, Rankin cod, blue spot emperor, flagfish and


53

rosy threadfin bream. The data was incorporated into a model that determined the likely impact of various levels of fishing effort on stocks of the key species, particularly red emperor and blue spot emperor.

In 1998, research surveys of the deeper areas adjacent to the existing trawl grounds were completed under a separate FRDC-funded project (Newman et al. 2000a). In 2002, the Department of Fisheries undertook a Natural Heritage-funded bycatch survey of the fishery (Stephenson and Chidlow 2003). The specific data requirements needed to assess performance for each of the relevant objectives are detailed in the relevant sections of the ESD reports in Section 5.1 Retained Species. Listed below are the current data collection systems in place. Monitoring Program Information Collected Robustness CAES for trawl fishery Monthly or trip summaries

of trawl catch (by species) and fishing effort (days). Monthly summaries available since the 1989.

Moderate

Voluntary trawl skippers logbooks.

Shot by shot estimates of trawl time, location & catch by species. Available since 1993 for target species only.

CAES for trap fishery Monthly or trip summaries of trawl catch (by species) and fishing effort (days). Monthly summaries available since the 1985.

Moderate

Catch by line fishery Monthly summaries of line catch (by species) compiled by licensees and stored in CAES system. Available since 1985.

Age structure study Determined the age structure and biological characteristics for red emperor, rankin cod and blue spot emperor. 1999. Data collection for the next age structure study began in June 2004.

High

Catch by recreational fishery

Occasional recreational catch surveys. Last survey of Pilbara region was conducted in 1999-2000.

Moderate

Catch and effort by charter boat fishery

Compulsory logbooks. Trip summaries of catch & effort by fishers.

Moderate


54

Available since 2001. Vessel Monitoring System Monitors trawling and trap

fishing location and effort since 1998 and 2000, respectively.

High

Assessment 1.1.3 The distribution and spatial structure of the stock(s) has been established

and factored into management responses. The distribution for the target species in this fishery is well documented. Section 2.7 of this report covers the biology of each species including their distributions. The current data for all these species suggests limited larval dispersal and limited adult movement within populations of each species thereby supporting the current area-based management strategy for this species in the fishery as well as regional populations being treated as separate stocks for fishery management purposes. 1.1.4 There are reliable estimate of all removals, including commercial

(landings and discards), recreational and indigenous, from the fished stocks. These estimates have been factored into stock assessments and target species catch levels.

Within the list of monitoring programs outlined above for the PFTIMF data covering each of the sources of removal are outlined. While there is no indigenous fishery there is a recreational fishery. Catches by all methods (trawl, trap and line) and sectors (commercial, recreational and charter) are included in the stock assessments of each target species, which include age-structured models of some indicator species. Sector Catch Data Collected Frequency Commercial Fishers monthly or trip

summaries (CAES). Catch, effort and location for trawl, trap and line fisheries.

Monthly or trip based during the season.

Charter Boat Compulsory logbook with trip summaries of catch and effort.

Annually since 2001.

Recreational Catch Surveys. Occasionally; last survey done in 1999-2000.

Indigenous N/A N/A Illegal Estimated from

compliance data. Annually.

1.1.2 There is a robust assessment of the dynamics and status of the

species/fishery and periodic review of the process and the data collected. Assessment should include a process to identify any reduction in biological diversity and/or reproductive capacity. Review should take place at regular intervals but at least every three years.


55

1.1.5 There is a sound estimate of the potential productivity of the fished stock/s and the proportion that could be harvested.

The history for PFTIMF (around 15 years) combined with the extensive catch and effort data and research that has been collected for this fishery has enabled a very reliable estimate of the sustainable yield to be calculated for the fishery. These have been translated into the indicators and performance measures used to manage and ensure the sustainability of the fishery. The management for the fishery is adaptive and tailored to the major target species groups in the fishery. As previously mentioned, there are three indicators used to monitor the two target species groups for the fishery, long-lived and short- lived species. These are reviewed annually and if triggered action is taken whether it be the review of the data or reduction in effort. In addition, this fishery is managed through zones therefore taking into account the distribution and allowing the management to be tailored to the particular species or area. The status of the breeding stocks and intra-annual variation for the two primary target species groups in the fishery are assessed and evaluated every year using a synthesis of information obtained from the fishery. A review of the performance for this fishery is conducted at least once a year. This review includes an assessment of the total catch by the fishery, the level of effort to take the catch, the distribution of effort, both spatially and temporally across the season and the calculated catch rates. These assessments are reported annually within the State of the Fisheries Report. Using the indicators as described above in 1.1.2, 1.1.3 and 1.1.6, four of the major long- lived target species (Rankin cod, spangled emperor, goldband snapper and red snapper) were below the acceptable performance limits in 2001 and two species (Rankin cod and spangled emperor) were below performance limits in 2002 (Table 7). Table 7 Indicators for major long-lived target species a) total estimated

spawning biomass (SB) as a percentage of virgin level; b) ratio of annual catch to average of annual catch in previous 4 years; c) ratio of annual catch rate to catch rate in previous year. Years in which these indicators would have triggered a review are shown.

Species

a) SB

in 2002

b) Catch ratio

00 01 02

c) Catch rate ratio

00 01 02

Review?

01 02

Review if : < 40% > 1.20 <1.00 in 2 consecutive yrs

Red emperor 40% 0.54 0.76 0.98 0.92 1.00 1.14 no no

Rankin cod 55% 0.52 0.56 0.60 0.77 0.71 0.96 yes c yes c

Spangled emperor n/a 0.37 0.74 0.57 0.98 0.83 0.84 yes c yes c

Goldband snapper n/a 0.75 1.23 1.03 0.96 1.50 0.89 yes b no

Red snapper n/a 0.97 1.40 1.16 1.15 1.33 1.09 yes b no

Scarlet perch n/a 0.62 1.01 1.01 0.95 1.25 1.00 no no


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The catch rate of red emperor declined during the mid 1990s (Figure 8) and biomass was estimated at below 40% of the virgin level. This situation prompted effort reductions in the trawl fishery, and these actions appear to have arrested the decline in catch rate. In 2001, the age-structured stock assessment model suggested that the total biomass of red emperor was at 49% of the virgin level but that this species was slightly over-exploited in Areas 1 and 5. In 2002, total biomass was estimated at approximately 50% of the virgin level and the catch rate increased in 2002 and 2003.

In 2002, the total spawning biomass of Rankin cod was estimated at 55% of the virgin level, although there was localised depletion in Area 5, where local biomass was 33% of the virgin level. The catch rate of Rankin cod has been declining since the mid 1990s. Recent effort reductions in the trawl fishery appear to have slowed this decline. However, the catch rate of Rankin cod still declined slightly between 2001 and 2002, and contributed to a decision to further reduce trawl effort in 2003. The triggering of indicators in 2001 and 2002 reflected the status of this species.

The catch and catch rate of spangled emperor declined between 1998 and 2002 (Figure 8). Biomass estimates are not available for this species but trends in catch and catch rate suggest that this species should be monitored closely in the future. The triggering of indicators in 2002 reflected this status.

Figure 8. Annual catches and catch rates of the six major, long-lived, target species caught by the PFTIMF, 1989-2002.

The catch and catch rate of goldband snapper was high in 2001 and 2002, and probably reflected increased targeting of this species. Significant recent catches of this species by the line fishery prompted trawl and trap fishers to seek a review of the line fishery in 2001. As a result, a management plan for the line fishery is currently being developed and may assist in controlling future line catches of goldband snapper. The increasing catches of goldband snapper in all sectors (trawl, trap and line) was suggested by industry as a reason for undertaking a full stock assessment of this species. However, the poor quality of available catch rate data and the absence of age composition data would make full stock assessment of this species difficult.

0

50

100

150

200Rankin cod Spangled emperor

Goldband snapper

0

2

4

60

100

200

300

400

Red snapperRed emperor Scarlet perch

0

6

12

18

Cat

ch r

ate

(kg/

day)

Cat

ch (

t)

90 92 94 96 98 00 02

Year Year90 92 94 96 98 00 02

0

50

100

150


Goldband snapper

0

50

100

150


Goldband snapper

0

2

4

6

0

2

4

60

100

200

300

400


0

100

200

300

400


0

6

12

18

0

6

12

18

Cat

ch r

ate

(kg/

day)

Cat

ch (

t)

90 92 94 96 98 00 02

Year Year90 92 94 96 98 00 02


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From 1994 to 2002, the catch and catch rate of scarlet perch showed little variation, suggesting that the stock of this species may be stabilising at an adequate level.

The catch of red snapper was variable from 1995 to 2002, but there was no overall decline. Catch rates increased steadily over the same period. The stock of red snapper appears to be at a satisfactory level.

Management Responses 1.1.6 There are reference points (target and/or limit) that trigger management

actions including a biological bottom line and/or a catch or effort upper limit beyond which the stock should not be taken.

The Department of Fisheries manages the take for the two primary species groups through the spawning biomass of red emperor and Rankin cod (for long- lived species) and blue-spot emperor (for short- lived species), annual trawl catch and catch rate of each of the major target long- lived and short- lived species. Red emperor and rankin cod are used as indicator species for the long- lived target species. It is assumed that management measures that protect stocks of these indicator species will afford similar levels of protection to the other long- lived species that are caught by this fishery. Blue-spot emperor is used as the indicator species to represent the short- lived target species in the fishery. Reliable catch and effort data is available for this species since 1993, although adequate data for modelling is only available in Area 1, where most of the blue-spot emperor catch occurs. Monitoring the catch levels and catch rates for the major short- lived target species, as well as the catch of blue-spot emperor will assess the general success of management measures. For all the major target fish species for both long- lived and short- lived groups caught, if the performance limits are exceeded the Department of Fisheries has a series of management actions which it could be adopted prior to the start of the next season or within a season depending on the situation. There are a series of reference limits for each indicator used in this fishery for the major long- lived species caught. These are: 1) Spawning biomass of Rankin cod and red emperor should remain above a minimum limit of 40% of the virgin spawning biomass. Evidence from other fisheries suggests that a limit of 35%, with a target of 40%, of the virgin biomass is appropriate to ensure sustainability of the fishery (Mace 1994; Mace and Sissenwine 1993; Die and Caddy 1997; Gabriel and Mace 1999). The spawning biomasses of red emperor in 1972 and Rankin cod in 1989 are assumed to represent the virgin level. In the Pilbara, reliable catch data for red emperor is available from 1972, and available for Rankin cod from 1990. 2) Annual trawl catch of each long- lived target species should not increase > 20% above the average annual catch of the previous 4 years. 3) Annual trawl catch rate of each long- lived target species should not decrease in two consecutive years. There are a series of reference limits for each indicator used in this fishery for the major short- lived species caught. These are:


58

1) Spawning biomass of blue-spot emperor should remain above a minimum limit of 40% of the 1993 spawning biomass in Area 1. Evidence from other fisheries suggests that a limit of 35%, with a target of 40%, of the virgin biomass is appropriate to ensure sustainability of the fishery (Mace 1994; Mace and Sissenwine 1993; Die and Caddy 1997; Gabriel and Mace 1999). The spawning biomass of blue-spot emperor in 1993 is assumed to represent the virgin level. 2) Annual trawl catch of each short- lived target species should not increase > 20% above the average annual catch of the previous 4 years. 3) Annual trawl catch rate of each short- lived target species should not decrease in two consecutive years. Table 8 Indicators for major short -lived target species. a) total estimated spawning biomass as percentage of virgin level; b) ratio of annual catch to average of annual catch in previous 4 years; c) ratio of annual catch rate to catch rate in previous year. Years in which these indicators would have triggered a review are shown.

Species a) Spawning biomass in 2002

b) Catch ratio 00 01 02

c) Catch rate ratio 00 01 02

Review? 01 02

Review if : < 40% > 1.20 < 1 in 2 consecutive yrs

blue-spot emperor

> 40% 0.72 0.64 1.05 0.94 0.73 1.31 yes c no

flagfish n/a 0.86 0.91 1.36 0.92 0.95 1.49 yes c yes b

frypan snapper n/a 0.46 0.51 1.14 0.79 0.86 1.31 yes c no

threadfin bream n/a 0.76 0.90 1.91 0.90 1.12 1.93 no yes b

1.1.7 There are management strategies in place capable of controlling the level

of take. A full description of the management arrangements is located in the attached Pilbara Fish Trawl Fishery Interim Management Plan 1997. A full discussion of the main regulations and their justifications are located in Section 2. The fishery is managed by input controls including gear restrictions, area closures and total and area effort limitations. Significant effort is put into ensuring adequate compliance with these regulations. This includes at-sea and aerial patrols to ensure closed season and areas, as well as operational rules are being adhered to. The use of VMS (since 1998) on the vessels has helped the Department of Fisheries monitor vessel location and speed thus increasing compliance within closures while decreasing random patrol activities (full details on Compliance activities and their effectiveness are located in Section 5.4.1.3).


59

1.1.8 Fishing is conducted in a manner that does not threaten stocks of by-product species.

A full description of the information available and the levels of risk of impact on the by-product species group by the PFTIMF are located in section 5.1.2. Five groups of by-product species were identified for this fishery only elasmobranchs group was given a high enough risk rating (Moderate) to warrant a full report. Other scalefish, bugs, cephalopods and shells were given a Low Risk rating. Other Scalefish Approximately 37 taxa of other scalefish (i.e. species caught in addition to those listed above as primary target species) are reported on monthly returns by the fishery. The total annual reported catch of ‘other scalefish’ by the fishery ranged from 767 tonnes to 1140 tonnes between 1998 and 2002. In 2002, the reported catch (767 t) of ‘other scalefish’ represented 31% of the total PFTIMF catch, and 33% of the total PFTIMF scalefish catch. Reported catches of individual species were between 0 and 138 tonnes and are shown in Table 14 in Section 5.1.2.1. Elasmobranchs Twenty-four species of sharks and 10 species of rays are known to be caught by this fishery. Of these, 14 species of sharks and 3 species of rays are known to be retained in small quantities as by-product. Generally, only large individuals of any species are retained. Sandbar shark, Carcharhinus plumbeus, is one of the main shark by-product species in this fishery. Sandbar sharks, and most other species of shark, have a highly K-selected life history (i.e. long-lived, slow growth, low reproductive potential). Such species are highly susceptible to over-fishing and may take many generations to recover. Sandbar shark is the primary component of the catch in the West Coast Demersal Gillnet and Demersal Longline Fishery (WCDGDLF) and in the North Coast Shark Fishery (NCSF) and is caught as a by-product species in several State and Commonwealth-managed fisheries. These fisheries also catch some other species of sharks that may be caught in minor quantities in the trawl fishery. The quantities of sandbar shark and other sharks caught as by-product by the Pilbara fish trawl fishery are relatively minor compared with catches of the dedicated shark fisheries. This suggests that the impact of the trawl fishery on shark populations is minor. However, there is some uncertainty about the true level of exploitation of each shark species because sharks caught as by-product by the trawl fishery are generally not reported by species. Also, only 2 of the shark species (sandbar and dusky sharks) likely to be caught by the fishery have been formally assessed. No estimates of breeding stock biomass are available for any of the shark species taken as by-product by the fishery. However, preliminary estimates of the exploitation rates of sandbar shark have been assessed as sustainable, as determined from a study of tag recaptures (Lenanton, unpublished). Sandbar shark is the major target species in the region, but it has only recently become the primary target species


60

in the WCDGDLF and the NCSF, and severe stock depletion is unlikely to have occurred yet. The low quantities of each species, including sandbar shark, caught by the PFTIMF are unlikely to have a significant impact on breeding stock biomass of any species. The Department of Fisheries is implementing indicators such as level of total shark catch and catch level of selected target species which will improve the quality of reporting of shark catches. Catches of each species are required to assess stock status. This is particularly important for sandbar shark. The Department of Fisheries has recently published an identification guide (McAuley et al 2002) to assist commercial fishers in identifying sharks to species level. Bugs The annual catch of bugs by this fishery has ranged from 3 to 7 tonnes between 1998 and 2002. In 2002, the catch was 5 t, which represented 14% of the total WA state catch (38t) of bugs. The area of the trawl fishery in which bugs are taken is small relative to the total distribution of this species. It is proposed that a Code of Conduct be developed by industry to promote the release of juveniles and berried female bugs. Cephalopods Pharaohs cuttlefish (Sepia pharaonis) and squid (Family: Loliginidae) are retained as by-product by the fishery. Squid are caught in very minor quantities. In general, cuttlefish and squid have a low susceptibility to overfishing because they grow rapidly and have a very high rate of natural mortality. Mass mortalities occur after spawning. Pharaohs cuttlefish reach at least 26 cm mantle length and the life cycle is less than 10 months in captive animals (Norman 2000). Loliginid squid typically live for 1-2 years and mature after 1 year or less (Dunning and Lu 1998). Cuttlefish were heavily exploited by Taiwanese trawlers on the North-West Shelf, with peak landings of >8400 t in 1982 (Kailola et al. 1993). By comparison, recent cuttlefish catches in WA have been relatively small, with a total of 59 t reported in 2001 and 126 t in 2002. In the PFTIMF, annual catches ranged from 22 to 104 t between 1998 and 2002. The catch in 2002 (104 t) represented 83% of the total WA state catch. The standing stock of loliginid squids on the North-West Shelf has been estimated at 4500 t (Lui and Yeh 1984). By comparison, recent catches of squid in Western Australia have been small, with a total of 48 t reported in 2001. Approximately 2.5 t of squid was caught and retained by the PFTIMF in 2002. This catch represented 3% of the total WA state catch. The low trawl catch is partly due to the selectivity of the 100 mm mesh used in fish trawl nets, which does not effectively retain small squid. Shells This fishery incidentally catches shells. Some larger shells are retained by the crew for personal use or sold to collectors. The composition of the shell catch is unknown. The 2002 Bycatch Survey (Stephenson and Chidlow 2003) caught 30 "conch" shells


61

(Buccinidae) and 20 "bailer" shells (Volutindae) in 427 trawl shots. All individuals were alive when landed. Discarded shells have a high probability of survival after capture and release by the fishery. Total quantities of shells retained by the PFTIMF are low. Also, the area of the trawl fishery in which shells can be taken is small relative to the total range of each species. Therefore, the impact of the fishery on each retained species is likely to be minor. Within the fishery, potential shell habitats include areas of rough ground and closed areas (Zone 1, Areas 3 and 6). These areas are not subject to trawling and so provide refugia for shells. The shells taken by fish trawling are deep-water species. They are generally different to those species taken by Specimen Shell fishery licensees, who are restricted to hand collecting and therefore can only collect shallow water species. Shells collected by fish trawling are not typically of high quality, but fetch reasonable prices because of their rarity on the market. This rarity is due to the difficulty of collection and is not a reflection of low abundance. The shells caught during the recent bycatch survey were not fully identified and may have comprised up to 6 different species. The catch included individuals of Melo sp., probably M. umbilicatus (Volutinidae), and individuals tentatively identified as Syrinx aruanus (Buccinidae). The Specimen Shell fishery reported collecting zero M. umbilicatus and 2 S. aruanus in 2002. In 2000/01, licencees in the Specimen Shell fishery reported a total catch of 20,138 shells. The reported catch comprises over 460 species. Of these, only six species of cowries (Cypraeidae) - Cypraea friendlii vercoi, C. marginata (albanyensis), C. marginata (consueta), C. rosselli, C. reevii and C. venusta - and 2 species of volutes (Volutidae) – Amoria damoni (keatsiana) and A. damoni (reevi) - have been identified as vulnerable to over-exploitation (Ponder and Grayson 1998, Wells 2002). The Specimen Shell fishery collects between 50 and 600 individuals of each species per year. The trawl fishery does not collect these vulnerable species. 1.1.9 The management response, considering uncertainties in the assessment

and precautionary management actions, has a high chance of achieving the objective.

Management actions taken within this fishery over the past 15 years has been very effective and there is, therefore, a very high probability that they will continue to achieve the main objective of maintaining the spawning stocks for the major target species caught, which in turn is likely to maintain the stocks of other long- lived and short- lived species taken by the fishery. Since the commencement of the interim management arrangements in 1998, the Department has further reduced the total effort within the fishery to maintain the stock levels. Effort has also been redistributed among areas within the fishery with the aim of maximising yield whilst keeping exploitation rates of the indicator species (red emperor and rankin cod) at sustainable levels. For example, effort has been reduced in areas of high red emperor abundance and redistributed to areas of high abundance of more robust, short- lived species.


62

Furthermore, the management strategy allows for some flexibility within areas in terms of total effort. Since 1998, annual effort allocations have been exceeded in some areas, but not reached in other areas (see Table 3 in Section 2.2.5). In 2002, amendments to the interim management plan limited the over-run of time in any area to no more than 48 hours per licence. The use of indicators and performance measures for the major target species allow the Department to respond to changes outside the normal variations thus ensuring the maintenance of the spawning stock for all species. If the performance limits are reached, management arrangements can be implemented (See 5.1.1). If an annual review suggests that performance limits were exceeded because of a decline in spawning biomass, the management response would be an adjustment of the effort allocations in the fishery as has been shown in the past with this fishery.


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OBJECTIVE 2. RECOVERY OF STOCKS Where the fished stock(s) are below a defined reference point, the fishery will be managed to promote recovery to ecologically viable stock levels within nominated timeframes. No stocks in this fishery are considered to be below their defined levels.

PRINCIPLE 2 OF THE AUSTRALIAN GOVERNMENT GUIDELINES

OBJECTIVE 1. BYCATCH The fishery is conducted in a manner that does not threaten bycatch species.

Dolphins

Turtles

Sea snakes

Sawfish

Sygnathids

Protected species

Morey eels

Unmarketable scalefish

Elasmobranchs

Macro-invertebrates

Other

Capture

Benthic organisms

Direct Interaction but no capture

Non Retained Species

Nine non-retained (bycatch) species/groups were identified in this fishery and are shown above in the component tree. Four out of the nine groups identified were given a Moderate Risk rating thus requiring a full report. It was determined that the fishery was of Low Risk to the other five groups (Seasnakes, Moray Eels, Unmarketable species, Elasmobranchs and Macro- invertebrates). As a result of the Low Risk rating accorded to these issues only a brief justification was required (Section 5.2). The threatened and protected species are covered in Objective 2.2; the remaining non-retained species are covered under objective 2.1. The minimal bycatch issues associated with this fishery and the low risks involved demonstrates that the performance of the fishery is not threatening any bycatch


64

species, including protected and threatened species. Consequently, it is meeting both objectives 1 and 2 of Principle 2. Information Requirements 2.1.1 Reliable information, appropriate to the scale of the fishery, is collected

on the composition and abundance of bycatch. In 2002, the Department of Fisheries undertook a Natural Heritage-funded bycatch survey of the fishery (Stephenson and Chidlow, 2003). The survey was conducted on the existing commercial vessels in the fishery in order that the conditions of the trawls would be representative of usual operations. The results of the Bycatch Survey have been used in the development of this application. Furthermore, there are the anecdotal reports from fishers to support the information collected in this fishery and adjacent fisheries (e.g. NDSMF) in respect to bycatch. All this information has been used in the development of this report. Assessments 2.1.2 There is a risk analysis of the bycatch with respect to its vulnerability to

fishing. A formal risk assessment for the identified non-retained/bycatch species was completed (see Section 3.2 for details on how this was completed). This assessment concluded that the PFTIMF was of low risk to moray eels, unmarketable scalefish, elasmobranchs and macro- invertebrates. Moray Eels – Summary ERA Risk Rating (C1 L6 LOW) The fishery occasionally catches moray eels and the majority are released alive. They tend to occur in the catch attached to pieces of coral or sponge. The 2002 Bycatch Survey (Stephenson and Chidlow 2003) caught 192 moray eels, which were probably Gymnothorax undulatus, in 427 trawl shots. Data from the survey suggest that approximately 2500 moray eel are caught and released alive by the fishery per year. Moray eels are not known to be caught in significant quantities by any other fishery in the region. See Section 5.2.2.1 for further information. Unmarketable scalefish - Summary ERA Risk Rating (C1 L6 LOW) Numerous species of scalefish are caught and discarded by the fishery, generally because they are unmarketable. Results of the 2002 Bycatch Survey (Stephenson and Chidlow, 2003) suggested that approximately 1000 t of scalefish are discarded by the fishery per year. The total number of scalefish species caught and discarded by the fishery is unknown, but may exceed 100. Many discarded species are rare in catches and so annual catches of each species are very small. The bycatch survey identified 31 taxa that comprise the bulk of scalefish discards by the fishery. These taxa are listed in Table 17 in Section 5.2.2.2. Some of these species are caught in significant quantities only by the PFTIMF and many are


65

discarded when caught by any fishery because they are of little or no commercial value. Elasmobranchs - Summary ERA Risk Rating (C0 L6 NEGLIGIBLE) Twenty four species of sharks and 10 species of rays are known to be caught by this fishery. Approximately 60% (by weight) of the shark catch is discarded. The majority of rays are discarded. Results of the 2002 Bycatch Survey (Stephenson and Chidlow 2003) suggested that approximately 150 t of sharks are discarded by the fishery per year. While the total discarded catch of elasmobranchs by the fishery is significant, the discarded catch of each species is small. Other fisheries also discard most the elasmobranch species discarded by this fishery. Larger sharks have a higher probability of survival after release than smaller sharks. The area of the fishery in which elasmobranchs are vulnerable to trawling is small relative to the total distribution of each species. For more information see Section 5.2.2.2 Management Responses 2.1.3 Measures are in place to avoid capture and mortality of bycatch species

unless it is determined that the level is sustainable (except in relation to endangered, threatened or protected species). Steps must be taken to develop suitable technology if none is available.

2.1.4 An indicator group of bycatch species is monitored. The combination of the low level of effort, area closures and the relatively small area in which the PFTIMF operates, greatly reduces the impacts on all of these affected species. Due to the minimal risks associated with this group of non-retained species, it is not necessary to monitor or implement further management for any of these species in the longer term. Even so, the Department of Fisheries is proposing for a Bycatch Survey for this fishery to be conducted every 5 years and a Code of Conduct to be developed for the fishery. It is proposed that this Code of Conduct be developed by industry to promote i) catch sorting procedures that maximise survivorship after release, ii) the release of berried female crustaceans, and iii) the release of species that fishers are not licenced to retain. A Bycatch Action Plan is being developed for the fishery that will detail the management of bycatch. 2.1.5 There are decision rules that trigger additional management measures

when there are significant perturbation in the indicator species numbers. The risks associated with this group of species will be reassessed at the next major review of this fishery. This will occur within five years, as a requirement of the WA ESD policy.


66

2.1.6 The management response, considering uncertainties in the assessment and precautionary management actions, has a high chance of achieving the objective.

Given the relatively low levels of interactions for the PFTIMF with non-retained species, it is more than likely that the current situation of having only negligible impacts on these species will continue. Nonetheless, as monitoring data becomes more available, the suitability of the current performance limits may need to be reviewed. If they are inappropriate and/or the level of interactions increases, appropriate alterations to the practices will be taken.


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OBJECTIVE 2. PROTECTED/LISTED SPECIES The fishery is conducted in a manner that avoids mortality of, or injuries to, endangered, threatened or protected species and avoids and minimises impacts on threatened ecological communities. Assessments 2.2.1 Reliable information is collected on the interaction with endangered,

threatened or protected species and threatened ecological communities. The Department of Fisheries (WA) and members of the PFTIMF have agreed on a long-term strategy for the management of listed species bycatch in the Fishery. The agreed three-phase process for dealing with the bycatch of listed species involves the collection of baseline data (to clarify the extent of the problem); secondly, the development and trialling of mitigation measures; and finally the implementation of new management arrangements (including legislation). The process is expected to take three to four years in total. The first phase is underway with the Department having carried out two on-board observer trips in June 2004 as part of a longer-term program to collect data on the bycatch of listed species (in particular dolphins, turtles and sawfish). The Department has successfully secured funding from the Fisheries Research and Development Corporation (FRDC) to develop and trail bycatch mitigation devices. The Department proposes to begin trialling devices once extensive baseline data has been collected against which the effectiveness of the mitigation devices can be measured. This is expected to begin around December 2004. The Department’s Research Division and members of the Fishery have agreed to trial grids of differing materials and sizes (to deter, or provide an escape mechanism for, turtles and dolphins), pingers (specifically designed to deter dolphins from trawl nets), and electro shark deterrents (to deter sharks and sawfish). The effectiveness of these devices will be monitored by underwater digital cameras as well as being measured against the baseline data. Furthermore, digital cameras mounted on the deck of vessels will monitor the catch composition of the Fishery. On-board observers will initially operate concurrently with the on-deck digital cameras to verify the footage but the longer-term intention is to have a reduced on-board observer program to act as an audit of the footage only. The Department of Conservation and Land Management has been collecting information on the interactions between fishers and turtles since 1973. This has been discussed in further detail in Section 5.2.2.2. Mawson and Coughran have collected and published information on records of sick, injured and dead pinnipeds in Western Australia. These records span from 1980 – 1996 and have been discussed in Section 5.2.1.1.


68

The Department of Conservation and Land Management has also collected information on whale interactions throughout the Western Australian state between 1985 and 2002. 2.2.2 There is an assessment of the impact of the fishery on endangered,

threatened or protected species. A formal risk assessment for the identified non-retained/bycatch species was completed (see Section 5.2 for details on how this was completed). This assessment concluded that the PFTIMF was of Moderate Risk to dolphins, turtles, sawfish and syngnathids. The PFTIMF was of Low Risk to seasnakes. Below is a table detailing the catches of protected/listed species in the Pilbara region and the estimated catches from the 2002 Bycatch Survey conducted in the fishery. The Department of Fisheries is proposing that a Code of Conduct be developed by industry to encourage the detailed reporting of all protected species interactions. It would also promote better handling practises that maximise the survivorship and promote fishing methods that are found to minimise capture of protected species. Table 9 Summary of catches of protected/listed species in the Pilbara region PFTIMF catches estimated from 2002 bycatch survey (Stephenson and Chidlow 2003).

Species PFTF annual catch

Catch by other north-west WA fisheries?

Species distribution

Population size

Bottle-nose dolphins

52 caught (none released alive)

Unknown World-wide

Turtles 78 green + 13 loggerhead caught (72% released alive)

Minor catch by prawn trawl fisheries since introduction of BRDs. Indigenous harvest.

Indo-pacific Populations of >10000 (loggerhead) & >50000 (green) individuals.

Syngnathids 52 spiny seahorse + 442 pallid pipefish caught

Possible catches by prawn trawl fisheries.

Indo-pacific

Sawfish 26 green + 78 narrow caught (none released alive)

Likely catches by prawn trawl, gill net and recreational fisheries.

Indo-pacific

Sea snakes 273 caught (100% released alive)

Likely catches by prawn trawl fisheries.

Indo-pacific

Dolphins- Summary ERA Risk Rating (C2 L6 MODERATE) The 2002 Bycatch Survey (Stephenson and Chidlow 2003) caught 4 bottlenose dolphins (Tursiops truncates) during 427 trawl shots. All were dead. Projections from the survey and anecdotal information suggest that between 50 and 100 dolphins are killed by the fishery per year. No estimate of population size is available for the


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Pilbara region but bottlenose dolphins occur in tropical and temperate waters around the world and are common across northern Australia. The Department of Fisheries is proposing to establish a Dolphin Expert Panel to review data on the fishery and its interactions with cetaceans and develop ways to mitigate the interaction, if necessary. For further information see Section 5.2.1.1. Turtles - Summary ERA Risk Rating (C4 L3 MODERATE) The 2002 Bycatch Survey (Stephenson and Chidlow 2003) caught 6 green turtles (Chelonia mydas) and 1 loggerhead turtle (Caretta caretta) in 427 trawl shots. The loggerhead and 1 of the green turtles were dead when landed. The others were released alive. Anecdotal reports from fishers suggest that turtles are only occasionally caught by the fishery and are generally released alive. Data from the survey estimated that the fishery catches 91 turtles per year and, of these, approximately 72% are released alive. The area of the fishery in which turtles are vulnerable to capture is small relative to the total range of each species. However, turtles grow and reproduce slowly and so even low levels of fishing mortality may be unsustainable. The full rationale for the moderate risk rating for this issue is documented in Section 5.2.1.2. Seasnakes – Summary ERA Risk Rating (C1 L6 LOW) Sea snakes are occasionally caught by the fishery and the majority are released alive. The 2002 Bycatch Survey (Stephenson and Chidlow 2003) caught 21 sea snakes, which were probably Hydrophis elegans, in 427 trawl shots. All individuals were released alive. Data from the survey suggest that approximately 270 sea snakes are caught and released alive by the fishery per year. For further information see Section 5.2.1.3. Syngnathids – Summary ERA Risk Rating (C2 L6 MODERATE) The 2002 Bycatch Survey (Stephenson and Chidlow 2003) caught 34 pallid pipefish (Solegnathus hardwickii) and 4 spiny seahorses (Hippocampus histrix) in 427 trawl shots. Most individuals were dead when landed. Data from the survey suggest that approximately 450 pipefish and 50 seahorses are caught by the fishery per year. Sawfish – Summary ERA Risk Rating (C2 L6 MODERATE) The 2002 Bycatch Survey (Stephenson and Chidlow 2003) caught 2 green sawfish (Pristis zijsron) and 6 narrow sawfish (Anoxypristis cuspidata) in 427 trawl shots. Sawfish are generally killed by fishers to avoid personal injury when removing them from the net. Data from the survey suggest that approximately 25 green sawfish and 80 narrow sawfish are caught by the fishery per year.


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The area of the fishery in which green and narrow sawfish are vulnerable to capture is small relative to the total range of each species, suggesting that the fishery has limited impact on each population. However, sawfish grow and reproduce slowly and so even low levels of fishing mortality may be unsustainable. The global population of narrow sawfish has been estimated to be < 50% of virgin levels (Pogonoski et al. 2002). The status of green and narrow sawfish populations in north-western Australian is unclear but each species is believed to be relatively abundant, compared with other regions (R. McAuley pers. comm.). The limited information that is available about the life history of sawfish in Australian waters contributes to uncertainty about stock status. For further information see Section 5.2.1.4. 2.2.3 There is an assessment of the impact of the fishery on threatened

ecological communities. There are no threatened ecological communities associated with this fishery. Management Responses 2.2.4 There are measures in place to avoid capture and/or mortality of

endangered, threatened or protected species. All unintentional catches of the five protected species identified through risk assessment are required to be reported. Catches/discards are not currently reported. It is recommended that skippers record details of the catch, release and mortality of protected species such as seasnakes. Incidental captures of protected species will be reported in the annual status for the fishery. As was previously discussed, the Department is proposing additional management arrangements within the fishery, these are: • Digital Recording of catch on-deck– Digital cameras mounted on-deck will

record the catch of each vessel. The cameras which record 24 hours a day and store up to three months of data are currently being trialled in the fishery.

• Observer Program- The Department has implemented an observer program beginning with two on-board observer trips in June 2004. Industry and the Department propose to trial the digital on-deck cameras concurrently with the on-board observer program initially. However, the intention in the longer-term is that the observer program will simply act as an audit of the 24-hour on deck footage from each vessel.

• Trialling Mitigation Devices- The Department has successfully secured funding from the Fisheries Research and Development Corporation (FRDC) to develop and trail bycatch mitigation devices. The Department proposes to begin trialling devices once extensive baseline data has been collected against which the effectiveness of the mitigation devices can be measured. This is expected to begin around December.

The Department’s Research Division and members of the Fishery have agreed to trial grids of differing materials and sizes (to deter, or provide an escape mechanism for, turtles and dolphins), pingers (specifically designed to deter dolphins from trawl nets), and electro shark deterrents (to deter sharks and sawfish). The effectiveness of these devices will be measured against the baseline data and in addition, will be monitored by underwater digital cameras.


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Furthermore, digital cameras mounted on the deck of vessels will monitor the catch of listed species.

• Bycatch Action Plan- The Department will develop a bycatch action plan for the fishery that will detail the management of the bycatch species (see section 2.5.3).

• Logbook- The skipper’s logbook will be extended to collect additional data on catch, release and mortality of bycatch species.

• Code of Conduct - The Department is proposing that a code of conduct be developed by industry for this fishery to encourage the reporting of all protected and other bycatch species. Also it should promote handling practices that minimise the mortality of the bycatch species.

• Dolphin Expert Panel- The Department proposes to develop a group to review, assess and determine future strategies in reducing the catch of cetaceans by the fishery.

2.2.5 There are measures in place to avoid impact on threatened ecological

communities. Not applicable. 2.2.6 The management response, considering uncertainties in the assessment


It is more than likely that the current situation will improve with the proposed additional management arrangements. As monitoring data becomes available, the suitability of the current performance limits (5.2.1) may need to be reviewed. If they are inappropriate and/or the level of interactions increases, appropriate alterations to the practices will be taken.


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OBJECTIVE 3. GENERAL ECOSYSTEM The fishery is conducted, in a manner that minimises the impact of fishing operations on the ecosystem generally.

Fishing(eg trophic levels)

Sand infauna

Large epibenthos

Benthic Biota

Bait collection(not in this fishery)

Ghost fishing(not in this fishery)

removal of/damage toorganisms by

Discarding/Provisioning

Translocation

addition/movementof biological material

Impacts on the biological community(eg trophic structure) through

Air quality(Fuel usage/Exhaust)

Water quality(Paper/plastic debris)

Other

Other Aspects of the Environment

The issues that relate to the broader ecosystem which were identified for the PFTIMF are shown above in the component tree. A risk assessment process subsequently assessed each of these issues with the information relating to each issue detailed in Section 5.3. Of the seven issues identified for the PFTIMF, four were of Low Risk (trophic interactions, and infauna, translocation and discarding/provisioning) the other two were rated as Negligible Risk (exhaust fumes and debris). The issue of large epibenthos was given a High Risk thus requiring a full report. Consequently, the current performance for the PFTIMF is meeting Objective 3 and this acceptable performance is likely to at least continue or improve in the future.


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Information Requirements 2.3.1 Information appropriate for the analysis in 2.3.2 is collated and/or

collected covering the fisheries impact on the ecosystem and environment generally.

Appropriate levels of information have been obtained for most of the issues identified, which has allowed a sensible assessment of the level of risk to be made. This information includes data collected, which is directly related to the PFTIMF - in terms of levels of catch and effort, observer surveys, gear designs, and understanding of spatial and temporal closures. As discussed in section 5.3.1.1, there are also a number of publications that provide valuable information on trophic interactions in addition to the research that the Department of Fisheries has undertaken and is currently working on within other similar fisheries. Assessments 2.3.2 Information is collected and a risk analysis, appropriate to the scale of

the fishery and its potential impacts, is conducted into the susceptibility of each of the following ecosystem components to the fishery.

A formal risk assessment was completed (see Section 5.3 for details) on each of the identified issues relevant to the PFTIMF (see component tree for issues). The identified issues were assessed and a summary of the outcomes is located in Table 11. Complete justifications are located in the performance reports in Section 5.3. Table 10 Summary of risk assessment outcomes for environmental issues related

to the PFTIMF. ISSUES RISK SUMMARY JUSTIFICATION FULL

DETAILS Removal of/damage to organisms:

5.3.1

Trophic Interactions

Low Scalefish comprise the majority of the retained catch of the fishery, either as target or by-product species. Scalefish also comprise the majority of the discarded catch. Discarded scalefish have a low probability of survival and so should be included in total removals by the fishery. In 2002, an estimated 3230 t of scalefish were caught (either discarded or retained) by the fishery. In addition, a total of 327 t of sharks/invertebrates were caught (either discarded or retained) by the fishery.

It is unlikely that total removals by the fishery would significantly disrupt trophic dynamics in the region. Most species in the scalefish catch are generalist carnivores and consume a

5.3.1.1


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wide range of fish and invertebrates from demersal habitats. Therefore, the impact of any reduction in scalefish predator abundance would be spread across many prey species. Also, there are other species of medium-sized carnivores in the Pilbara region that are not caught in significant quantities by the fishery and contribute to the total biomass of carnivores in the region. These non-target species play a similar trophic role to targeted species and would compensate for the effect of removals by the fishery.

It is possible that scalefish removals by the fishery have localised impacts in some Areas of the fishery that are open to trawling. However, overall catch rates of scalefish are stable in each Area which suggests that scalefish recruitment to the Pilbara region has not been affected by removals and that the total biomass of medium-sized, generalist carnivores in the region is probably being maintained at a level sufficient to maintain trophic function.

In a review of scientific studies on the effects of fishing on marine ecosystems, Jennings and Kaiser (1998) concluded that "where the functional and species diversity of fishes is relatively high, the indirect effects of fishing on the abundance of unfished prey species appears to be minor". Tropical marine waters, including the north-west shelf, are characterised by communities of high species diversity. In such systems, the overall effect of piscivores on their prey is substantial but the removal of one species, or a small group of species, is minor (e.g. Hixon 1991). In the Pilbara region, there is no evidence to suggest that the removal of scalefish by trawling has directly resulted in a significant trophic effect (i.e. extinction, appearance of new species or other measurable shift in ecosystem function). Examples of such "trophic cascades", which occur


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because fishing interferes with predator-prey (or herbivore-plant) interactions, are quite rare. Evidence to suggest a shift in the community composition on the north-west shelf due to fishing (Sainsbury et al. 1997) is thought to be associated with direct habitat removal by trawl gear rather than removals of target species. Although the trophic impact of total removals by this fishery was rated as LOW, the Department of Fisheries recognises that an assessment of trophic impacts by fisheries at a regional level, rather than at the individual fishery level, would be beneficial. Consequently, the Department will investigate the development of research to identify any detectable changes in the structure of coastal fish communities in this region over the last 40 years.

Sand Infauna Low Sand is a habitat type over which trawling commonly occurs. During operation, trawl nets are preceded by otter boards and "sweeps" (metal wires), which skim over the sand and disturb demersal fish. Fish are herded by this gear and become trapped in the net. The sweeps are approximately 90 m long and disturb the upper 6 centimetres of sand in front of the net (Moran and Stephenson 2000). Infauna associated with sand habitats may be disturbed by the actions of the boards, sweeps, bobbins and ground rope. The total trawled area of the fishery is approximately 27% of the total Pilbara demersal fish fishery (which encompasses both the trawl and trap fisheries). Within the trawl fishery, untrawled sand habitat occurs in closed areas (Zone 1, and Areas 3 and 6) and in locations adjacent to reef areas that are not trawled. Sand habitat also occurs north, south and inshore of the fishery boundary. All these areas provide undisturbed, local refugia for sand-dwelling fauna and are probably a source of recruitment to disturbed

5.3.1.2


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(trawled) sand habitats within in the fishery.

Trawling probably has limited negative impact on sand infauna and indeed is likely to have increased the area of habitat available to these communities. Sand habitats are naturally dynamic environments and resident infauna are adapted to cope with physical disturbances. Most of these organisms are small, short- lived and reproduce rapidly. Hence, infaunal communities of mobile sediments would be expected to be resilient to disturbance by trawling and recover rapidly (e.g. Kaiser et al. 1996). Collie et al. (2000) estimated that the recovery period of most sand infauna after disturbance would be approximately 100 d, and so these communities could typically sustain a frequency of disturbance of 2-3 times per year. Most sites within the Pilbara region are likely to be subject to trawling less frequently than this (Moran and Stephenson 2000).

Large Epibenthos

High Large attached epibenthos such as sponges, sea fans, seawhips, soft corals, hard corals and coralline algae, may be damaged or removed by the actions of the otter boards, sweeps, ground rope or bobbins on the trawl nets. Demersal trawling is known to be destructive to large epibenthos. It has been estimated that communities of attached epibenthos in open areas of the fishery experience annual rates of trawl- induced mortality of between 0.5 and 20% (Moran and Stephenson 2000). Sponges, soft corals and other large epibenthos provide adult habitat and nursery areas for invertebrates and fish, including some species targeted by the fishery. Some Lethrinus and Lutjanus species occur in inter-reef areas containing large epibenthos. Declines in catches of some of these target species, and increases in catches of other species such as lizardfish and threadfin bream, which are associated with sand habitats, have been linked to

5.3.1.3


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the loss of epibenthos habitats on the north-west shelf (Sainsbury 1997).

The rate of removal of epibenthos is related to the level of fishing effort. Therefore, current management measures that limit fishing effort within each Area not only constrain mortality of target species but also limit mortality on epibenthic communities. At most locations open to trawling, epibenthos mortality is estimated to be < 10% per year (Moran and Stephenson 2000), which may allow recovery of some faster growing epibenthic species. However, this may not allow regrowth of large (i.e. >25 cm) epibenthos (e.g. large sponges), which are generally believed to recover slowly (>15 y) (Sainsbury 1997).

Closed (untrawled) areas (Zone 1, and Areas 3 and 6) within the fishery provide refugia for epibenthos. Sixty percent of the Pilbara demersal fish fishery (encompassing both trawl and trap fisheries) in the depth range 30-120 m, is closed to trawling. Depths of 120-200 m, which also occur in the fishery, are not considered here because these depths contain markedly different types of epibenthic communities to the shallower areas of the fishery and are probably of a different type to those being impacted by the fishery (J. Fromont pers. comm., P. Stephenson unpubl data). Beyond the boundaries of the fishery, untrawled habitats for epibenthic communities occur to the north, south and east. Within open Areas (Areas 1, 2, 4 and 5), numerous small remnants of undisturbed epibenthos may occur in locations adjacent to reef areas that are not trawled. Therefore, there are untrawled areas in the Pilbara region that provide local refugia for epibenthic fauna and may be a source of recruitment to areas disturbed by trawling. Approximately 60% of the Pilbara demersal fish fishery (encompassing


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trawl and trap fisheries), at depths of 30-120 m, is closed to trawling and is intended to provide areas of refuge for benthic fauna. However, it is not known whether habitats in closed areas are comparable with those of open areas (i.e. are representative of the Pilbara region), or indeed whether closed areas contain any habitats suitable for epibenthic communities. The recent bycatch survey did not sample in closed areas. The total amount of closed area in the Pilbara region is large and so probably does contain some habitats suitable for epibenthic communities. Nevertheless, more data about the distribution of habitats in closed and open areas of the fishery is required to assess the effectiveness of closed areas as refugia for epibenthos.

Addition/Movement of biological material:

5.3.2

Translocation Low Five vessels operate in the PFTIMF fishery. In addition to fishing in the Pilbara region, one vessel may also travel to Carnarvon to fish for scallops and 2-3 vessels may travel to the Kimberley region to fish for prawns. Each vessel travels to Perth approximately once a year for maintenance. The hulls of vessels moving between regions could provide an opportunity for translocation of organisms. However, hulls are regularly anti- fouled. Also, the Leeuwin current flows along the length of the WA coastline, transporting biological material and resulting in a high level of connectivity between regions. Therefore, vessels in the fishery are unlikely to translocate organisms beyond the range of dispersal that would occur through natural processes. Vessels operating in the fishery do not use ballast water. Trawl nets are used only in the Pilbara region and are disposed of on shore, either at Point Samson (in the Pilbara region) or in

5.3.2.1


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Perth. The fishery does not use bait. Therefore, there is no translocation of exotic species and diseases by the fishery via these vectors.


Low Approximately 1000 t of scalefish, 150 t of elasmobranches and a small quantity of invertebrates are discarded by the fishery per year (Stephenson and Chidlow 2003). There is little processing of the scalefish catch onboard and so few fish waste products (e.g. heads, fins and guts) are discarded at sea. Waste products arise from the retained shark catch, which is generally processed at sea. Shark waste product (i.e. heads, guts) is equivalent to 37% of the landed catch and was approximately 25 t in 2002.

Some discarded elasmobranches and many discarded invertebrates (especially crustaceans and molluscs) have a high likelihood of survival after release and so do not contribute to "provisioning" by the fishery. The entire Pilbara demersal fish fishery covers an area of approximately 52,000 km2. If the total biomass of discards by the fishery is 1150 t per year, then an average of 22 kg of biomass are discarded per km2 per year across the entire fishery. At present, only 27% (14,040 km2) of the fishery is actually subject to trawling. If only this functional area of the fishery is considered, total discards result in an average of 82 kg of biomass being discarded per km2 (or 0.08 g per m2) per year. Discards occur over a wide area. Also, discards are likely to disperse as they sink in the water column due to currents, and so the impact of discarding will be diffused. The average annual rate (82 kg per km2 of trawled area) of provisioning by the fishery is low, relative to the biomass of food sources naturally available to carnivores and scavengers in the region.

5.3.2.2


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Other Environmental impacts:

5.3.3

Air Quality (Exhaust fumes)

Negligible There are the equivalent of 4.3 full time vessels operating in the fishery. The fishery covers an area of 14,980 nm2. Therefore, the risk is negligible.

5.3.3.1

Water Quality (Debris)

Negligible The fishery operates under an international code of practise that specifies the appropriate disposal of debris at sea. The obligations of fishers under this code are clearly displayed on each vessel. Plastics are not discarded at sea by the fishery. Paper debris may be discarded at sea, but only when vessels are >12 nm from shore. There are the equivalent of 4 full time vessels operating in the fishery, which covers an area of 14,980 nm2. The impact of any paper debris, which is readily biodegradable, being released by the fishery over this area is negligible.

5.3.3.2

Management Response 2.3.3 Management actions are in place to ensure significant damage to

ecosystems does not arise from the impacts described in 2.3.1. The most important management method required to ensure that there is minimal impact on the broader ecosystem include maintaining significant biomass levels of scalefish and other by-product species. In most cases, this serves to achieve both objectives of having a sustainable fishery and minimising the potential for any trophic interactions. 80% of the PFTIMF is closed to trawling and these areas are clearly defined. There are no proposals to open any of these areas to trawling and therefore, ecosystems within these areas are protected from trawling. Other management measures such as gear restrictions, limiting the number of operating vessels, and future research also further minimise the potential for general ecosystem impacts. With the proposal of future studies to be conducted to assess trophic impacts of fisheries at a regional level (i.e. development of research to identify any detectable changes in the structure of coastal fish communities) and damage to large epibenthos (i.e. CSIRO mapping results and additional bycatch surveys) an increase of information will be generated to more accurately assess these issues in the future.


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2.3.4 There are decision rules that trigger further management responses when monitoring detects impacts on selected ecosystem indicators beyond a predetermined level, or where action is initiated by application of the precautionary approach.

Only one of the issues identified for this category was of sufficient risk to require specific target levels. If future studies prove that risk to any of these issues has increased a review will take place and management will be implemented. 2.3.5 The management response, considering uncertainties in the assessment


The risk assessment identified that under current management arrangements there have been mostly minimal or negligible impacts from the PFTIMF on the broader ecosystem even after around 40 years of fishing (including the fishery itself and the foreign fisheries). It is, therefore, highly likely that this fishery will continue to meet the objectives of having only acceptable levels of impact. If future studies indicate that further management is required for any of the issues, then appropriate actions will be developed.


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5. PERFORMANCE REPORTS

5.1 RETAINED SPECIES

COMPONENT TREE FOR THE RETAINED SPECIES

Threadfin bream

Flagfish

Frypan snapper

Blue-spot emperor

Short-lived species

Rankin cod

Red emperor

Scarlet perch

Goldband snapper

Red snapper

Spangled emperor

Long-lived species

Primary Species

Elasmobranchs

Bugs

Cephalopods

Other finfish

Shells

By-Product Species

Retained Species

A yellow box indicates that the issue was considered a high enough risk to warrant a full performance report. A blue box indicates that the issue was considered a low risk, with no specific management required, and only a justification is presented.

5.1.1 PRIMARY SPECIES 5.1.1.1 LONG-LIVED SPECIES Rationale for Inclusion: Red emperor (Lutjanus sebae), Rankin cod (Epinephalus multinotatus), scarlet perch (Lutjanus malabaricus), goldband snapper (Pristipomoides multidens), red snapper (Lutjanus erythropterus) and spangled emperor (Lethrinus nebulosus) are the major, long- lived target species of the fishery. The fishery is capable of exerting a significant impact on the stocks of these species in the Pilbara region.

ERA Risk Rating: Impact on breeding stocks (C3 L4 MODERATE) These species have in common several life history traits – longevity, slow growth, low rate of natural mortality, relatively late age of maturity – that make them more vulnerable to overfishing than the other, shorter- lived target species. They fetch high market prices and are targeted by trawl, trap and line fishers in the Pilbara region.


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There is evidence of localised depletions of red emperor and Rankin cod, although total spawning biomass across the whole region is considered to be adequate for each species. In 2002, the total spawning biomass of red emperor in the Pilbara region was estimated to be at 50% of the virgin level (1972 level) and the total spawning biomass of Rankin cod was estimated to be at 55% of the virgin level (1989 level). These values were at or above the target virgin biomass level of 40%. The relationship between stock size and recruitment is unknown for each of these species. Since 1997, the catch rates of red emperor, scarlet perch, red snapper and goldband snapper have been stable, and the catch rates of Rankin cod and spangled emperor have declined slightly.

At the risk rating workshop in December 2002, participants agreed that the most appropriate consequence category for long- lived target species was 'severe'. However, there was some disagreement among participants as to the most appropriate levels of likelihood for each species. In each case, participants considered the likelihood as either 'possible' or 'occasional', which resulted in a risk rating of either MODERATE or HIGH, respectively. The outcome of both ratings is the same, i.e. both require a full performance report. In this report, the likelihood is given as 'possible' (level 4) resulting in a risk rating of MODERATE. This was chosen because the alternative likelihood ('occasional', level 5) infers that under current fishing levels, recruitment overfishing "will probably occur in most circumstances". Predictions from models about total biomass of long- lived target species indicate that this is not the case under current fishing effort levels.

Operational Objective To maintain the spawning stocks of red emperor, Rankin cod, red snapper, scarlet perch, goldband snapper and spangled emperor at or above levels that minimises the risk of recruitment overfishing.

Justification: An operational objective that maintains the potential for recruitment at historical levels is consistent with the statutory obligation under section 3 of the FRMA (1994) "to conserve, develop and share fish resources of the State for the benefit of present and future generations." Indicators Primary: Spawning biomass levels of Rankin cod and red emperor. Secondary:

1) Catch level of each of the 6 major long- lived target species.

2) Catch rates of each of the 6 major long- lived target species.

Rankin cod and red emperor are used as indicator species to represent the longer- lived target species in the fishery. The fishery is managed to maintain spawning biomass levels of Rankin cod and red emperor above reference levels (primary indicator). Red


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emperor is a long lived snapper used to represent the suite of long lived snappers and emperors and Rankin cod is a long lived species used to represent the more site attached species in the fishery. It is assumed that management measures that protect stocks of these two species will afford similar levels of protection to the other long-lived species. The validity of this assumption is assessed by monitoring the catch and catch rates for each of the major long-lived target species.

Performance Measures 1) The median spawning biomass of Rankin cod and red emperor should be above 40% of the virgin spawning biomass.

2) Annual trawl catch of each long- lived target species should not increase > 20% above the average annual catch of the previous 4 years.

3) Annual trawl catch rate of each long- lived target species should not decrease in two consecutive years.

Justification: Evidence from other fisheries suggests that a limit of 35%, with a target of 40%, of the virgin biomass is appropriate to ensure sustainability of the fishery (Mace 1994, Mace and Sissenwine 1993, Die and Caddy 1997, Gabriel and Mace 1999). The spawning biomasses of red emperor in 1972 and Rankin cod in 1989 are assumed to represent the virgin levels. In the Pilbara, reliable catch data for red emperor is available from 1972, and available for Rankin cod from 1989. Biomass levels of < 40% tend to coincide with declining catch rates of the long -lived target species. For example, in 2001 the model suggested that the biomass of Rankin cod was over -exploited in Area 5, where the biomass was 33%. This coincided with declining catch rates i n 2000, 2001 and 2002. Recent values of indicators are given in Table 11. Catch and catch rate indicators are consistent with spawning biomass assessments of red emperor and Rankin cod, which suggests that they are satisfactory measures of stock status.


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Table 11 Indicators for major long-lived target species. total estimated spawning biomass (SB) as a percentage of virgin level; ratio of annual catch to average of annual catch in previous 4 years; ratio of annual catch rate to catch rate in previous year. Years in which these indicators would have triggered a review are shown.

Species

a) SB

in 2002

b) Catch ratio

00 01 02

c) Catch rate ratio

00 01 02

Review?

01 02

Review if : < 40% > 1.20 <1.00 in 2 consecutive yrs

Red emperor 40% 0.54 0.76 0.98 0.92 1.00 1.14 no no

Rankin cod 55% 0.52 0.56 0.60 0.77 0.71 0.96 yes c yes c

Spangled emperor n/a 0.37 0.74 0.57 0.98 0.83 0.84 yes c yes c

Goldband snapper n/a 0.75 1.23 1.03 0.96 1.50 0.89 yes b no

Red snapper n/a 0.97 1.40 1.16 1.15 1.33 1.09 yes b no

Scarlet perch n/a 0.62 1.01 1.01 0.95 1.25 1.00 no no

Data Requirement for Indicator Data Required Availability

Catch & effort by trawl fishery

Monthly or trip summaries of trawl catch (by species) & fishing effort (in days). Compiled by licensees & stored in CAES system. Available since 1989.

Voluntary skippers logbooks. Shot-by-shot estimates of trawl time, location & catch by species. Available since 1993 for target species only.

VMS – monitors trawl fishing location & effort. Operational since 1998.

Catch & effort by trap fishery

Monthly or trip summaries of trap catch (by species) & effort (days, number of traps). Compiled by licensees & stored in CAES system. Available since 1985.

VMS – monitors trap fishing location & effort. Operational since 2000.

Catch by line fishery Monthly summaries of line catch (by species) compiled by licensees & stored in CAES system. Available since 1985.


Occasional recreational catch surveys. Last survey of Pilbara was conducted 1999-2000.

Catch & effort by charter boat fishery

Compulsory logbooks. Trip summaries of catch & effort. Compiled by fishers. Available since 2001.

Age structure data Age structure data for red emperor & Rankin cod, collected every 4 yr, would improve quality of assessments.

Data not currently being collected.


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Evaluation Summary: In 2002, the total spawning biomass of Rankin cod was estimated to be satisfactory at 55% of virgin level (1990 level), although there appeared to be localised depletion in Area 5. The total spawning biomass of red emperor was estimated to be 50% of the 1972 level. Biomass estimates for red snapper, goldband snapper and scarlet perch were not available but stable catch rates of these species in recent years suggested that spawning biomass levels were adequate. Biomass estimates for spangled emperor were not available. The decline in the catch rates of Rankin cod and spangled emperor between 1998 and 2002 suggested that levels of exploitation on these two species might be too high. A review in 2002 resulted in an effort reduction of 10% in Area 1 and 5 of the trawl fishery in 2004, with an equivalent reduction of 7% in the trap fishery.

Catch: The total commercial sector catch in 2002 is shown in Table 12.

Table 12 Commercial catches (to the nearest tonne) and the percentages (to the nearest 1%) of each major species taken by trawl, trap and line in the Pilbara in 2002.

Fish trawl catch Trap catch Line catch Total catch tonnes % tonnes % tonnes % tonnes Blue spot emperor 353 86% 57 14% 1 0% 411 Threadfin bream 363 100% - - - - 363 Red snapper 278 87% 41 13% - - 319 Flagfish 211 94% 13 6% - - 224 Goldband snapper 99 60% 38 23% 27 17% 164 Red emperor 79 65% 36 30% 6 5% 121 Scarlet perch 82 82% 12 12% 6 6% 100 Spangled emperor 19 28% 37 55% 11 12% 67 Frypan snapper 42 98% 1 2% - - 43 Rankin cod 17 42% 20 50% 3 8% 40 Other demersal scalefish 767 90% 51 6% 36 4% 854 All demersal scalefish 2,310 85% 306 11% 90 4% 2,706

Shark and ray 68 26% 0 193* 74% 261 Other by-product 112 100% 0 0 112 * Includes part of the North Coast Shark Fishery catch.

The catch of the long lived target species landed in 2002 (2001 catch in brackets) were red snapper 278 t (365 t), goldband snapper 99 t (122 t), scarlet perch 82 t (88 t), red emperor 79 t (74 t), spangled emperor 19 t (24 t), and Rankin cod 17 t (19 t).

The catches for 1989 to 2002 are illustrated in Figure 9. The catch of red snapper has increased for the last 10 years but has been variable in the last 4 years. Goldband snapper catches increased to a peak in 1997 then declined for 3 years with a subsequent increase in 2001 –2002. The scarlet perch catch peaked in 1997, decreased for 2 years, and then was stable from 1999-2002. The catch of red emperor peaked in 1995, and then declined to a stable level in 1999 – 2002. The spangled emperor catch peaked in 1997, and then dropped dramatically in 1997 with a steady decline from 1998 to 2002. The 1997 high catch may be principally due to misidentification and


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poor reporting. The Rankin cod catches peaked in 1995 and declined every year until 2002.

The fishery discards some undersized individuals of the long- lived target species (mainly red emperor). Results of the recent Bycatch Survey of the fishery suggested that approximately 5 t of red emperor are discarded per year (Stephenson and Chidlow 2003). The absence of tag returns from this species suggests high mortality of discarded red emperor (P. Stephenson, unpubl. data). However, undersized red emperor have a high rate of natural mortality and the total quantity of discards is low. Thus discarding is likely to have a minimal impact on the red emperor stock.

Figure 9. Annual catches and catch rates of the six major, long-lived, target species caught by the PFTIMF, 1989-2002.

Catch in other commercial fisheries: The trap fishery catch increased to 306 t in 2002 (266 t in 2001). The catch of the long- lived target species taken by the trap fishery in 2002 (2001 figures in brackets) were red emperor 36 t (30 t), blue spot emperor 57 t (43 t), goldband snapper 38 t (26 t), Rankin cod 20 t (21 t), and red snapper 41 t (35 t).

Demersal scalefish catches by line fishing were lower in 2002 at 90 t (99 t in 2001). The catches in 2002 (2001 figures in brackets) were mainly goldband snapper 27 t (38 t), spangled emperor 11 t (8 t), red emperor 6 t (4 t) and Rankin cod 3 t (4 t).

Although the total trap and line catch is low, relative to the trawl catch, quantities of each species may still be sufficient to have an impact on each stock. Trap and line catches are included in the stock assessment of each long- lived target species.

Trawl effort: The effort expended by the trawl fleet from 1986 to 2002 is shown in Table 13. The measure of effort used to calculate catch rate is 'VMS hours', i.e. hours spent within the boundaries of the fishery as measured by VMS. For the years prior to commencement of VMS in 1998, the VMS effort in each area was estimated from the logbook hours, with a multiplier of 1.34. It is likely that fishing efficiency will increase over time and cause catch rates calculated from nominal effort (i.e.

0

50

100

150


Goldband snapper

0

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4

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0

6

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18

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ch r

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ch (t

)

90 92 94 96 98 00 02

Year Year90 92 94 96 98 00 02

0

50

100

150


Goldband snapper

0

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150


Goldband snapper

0

2

4

6

0

2

4

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)

90 92 94 96 98 00 02

Year Year90 92 94 96 98 00 02


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unadjusted effort) to become progressively less indicative of decreases in stock size. Efficiency increases in the fishery have not been quantified. However, to provide a more realistic estimate of catch rate from 1994 to 2000, a modest increase in efficiency of 2% per year was incorporated into biomass modelling. The 2% efficiency increase per year estimate was based on extensive discussions with industry and is consistent with increases experienced in other Western Australian commercial fisheries for which we have extensive, long-term data (e.g. rock lobster, and prawns). Zero efficiency increase was assumed in 2001. Table 13 Summary of effort in the PFTIMF. Trawl effort (days) is from monthly

catch and effort returns, hours is nominal “net bottom time” effort from operators’ logbook data, and VMS hours is the time vessels spend inside the boundaries of the fishery.

Year (days) (hours) VMS hours

1985 - - 1986 19 - 1987 17 - 1988 32 - 1989 310 - 1990 698 - 1991 1,132 8,660 11,600 1992 983 10,030 13,440 1993 832 10,725 14,370 1994 1,484 22,087 29,600 1995 1,571 21,529 28,850 1996 1,550 25,246 33,830 1997 1,389 19,810 26,545 1998 1,291 20,555 27,609 1999 1,139 15,963 22,190 2000 957 14,084 21,199 2001 1,162 15,330 23,000 2002 1,035 17,329 20,544

Trawl Catch rates: After 1998, total effort in the fishery was reduced and redistributed among Areas to reduce fishing mortality on vulnerable target species, especially red emperor and Rankin cod. The effects of the effort reduction have noticeably arrested the decline in the catch rates of most of the species (Figure 9).

The red snapper catch rates increased for the last 10 years but have been variable in the last 4 years. The catch rate of goldband snapper declined from 1998 – 2000 but has increased in the last 2 years, probably due to fishing in previously lightly fished areas. The catch rates of scarlet perch were steady from 1998 to 2000, probably due to effort reductions, with increased catch rates in 2001 and 2002. The red emperor catch rate declined from 1995 to 1998, but has been stable from 1998 to 2001 with a healthy increase in 2002. The catch rate of spangled emperor declined from 1998 to 2002. Apart from an increase in 1999, the catch rates of Rankin cod declined from 1995 to 2002, indicating that fishing is having a negative impact on the stock of this species.

On an area basis, catch rates of red emperor and Rankin cod have stabilised at low levels in Area 1 but have decreased in the recently developed Area 5.


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Recreational component: A recent creel survey of boat and shore-based recreational fishing between Exmouth and Broome estimated that retained catches of spangled emperor and red emperor by boat-based recreational fishers were 12 t and 6 t, respectively, in 1999-2000 (Williamson et al. in prep). For both species, this represented 10% and of the commercial catch. Boat and shore-based recreational fishers do not catch significant quantities of Rankin cod, scarlet perch, red snapper or goldband snapper.

Charter and recreational catches in the region are not available annually, but estimates of annual catches are included in the stock assessment of each long- lived target species.

Stock assessment: Using the indicators as described above, four of the major long-lived target species (i.e. Rankin cod, spangled emperor, goldband snapper, red snapper) required a review in 2002 and two species (i.e. Rankin cod, spangled emperor) required a review in 2003 (Table 7).

The primary indicator, level spawning biomass, is determined for two long- lived target species, red emperor and Rankin cod.

Red emperor: The catch rate of red emperor declined during the mid 1990s (Figure 10) prompting effort reductions in the trawl fishery. The model outputs indicate an increase in the spawning biomass after 1998.

In 2002, the catch rate increased, and the age-structured stock assessment model suggested that the total biomass of red emperor was 50% the virgin level and increasing in all areas of the fishery. In Zone 1, the estimate is uncertain because catch rates were based on data from a small number of trap vessels operating over a short time period.

Figure 10. Spawning biomass (wi th 95% confidence intervals) as a percentage of

the 1972 level (black line); the biological reference point (40% of the 1972 level – dotted line); and the catch from all fishing sectors (columns) for red emperor in the Pilbara fishery. Data from 2003 onwards is projected from the model.


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Rankin cod: In 2002, the total spawning biomass of Rankin cod was estimated at 52% of the virgin level (Figure 11), but with localised depletion in Area 5 where local biomass was 33% of the virgin level. The estimate of total biomass is reasonably consistent with trends in the overall catch rate of Rankin cod, which has been declining in all open Areas of the trawl fishery since the mid 1990s. Recent effort reductions in the trawl fishery appear to have slowed this decline, but the continued decrease in catch rates for this species triggered a review in 2001 and 2002. Also, between 2001 and 2002 the trap catch rate of Rankin cod in the region west of 116°E (i.e. non-trawled region) declined slightly. However, the relationship between catch rate and stock status in this region is uncertain. Overall, the continuing decline of catch rates of this species contributed to a decision to further reduce trawl and trap effort in 2003.

Figure 11. Spawning biomass (with 95% confidence intervals) as a percentage of

the 1990 level (black line); the biological reference point (40% of the 1990 level – dotted line); and the catch from all fishing sectors (columns) for Rankin cod in the Pilbara fishery. Data from 2003 onwards is projected from the model.

The catch and catch rate of spangled emperor declined between 1998 and 2002 (Figure 9), which triggered a review in 2001 and 2002. Biomass estimates are not available for this species but trends in catch and catch rate suggest that this species should be monitored closely in the future.

The catch and catch rate of goldband snapper were high in 2001 and 2002, and probably reflected increased targeting of this species. Catches of this species by line fishing (commercial, recreational and cha rter) have also increased recently.

From 1994 to 2002, the catch and catch rate of scarlet perch have showed little variation, suggesting that the stock of this species is at an adequate level.


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The catch of red snapper has been variable from 1995 to 2002, but there was no overall decline. Catch rates increased steadily over the same period. The stock of red snapper appears to be at a satisfactory level.

Robustness: High The estimates and limits are considered highly robust because they are:

• calculated from several medium-term fishery-dependent and independent data sources.

• based on catch and effort data that are validated by cross-referencing between CAES, logbook and VMS sources.

• estimates of biomass on an area-specific basis.

• based on research methods that have been reviewed and published in scientific literature.

• of a statistically demonstrated high level of confidence.

Fisheries Management Response Current: The fishery is primarily managed through effort control, with area-specific effort units allocated to each licensee. There are 11 licences in the fishery, but an equivalent of only 4 full time vessels are currently operating. The value of an effort unit is reviewed annually and can be adjusted to change total or area-specific effort levels as required. Area 3 is closed to trawl and trap fishing and Area 6 is closed to trawl fishing.

The Pilbara trap and line fisheries and the recreational fishery take significant quantities of some long-lived target species. The Pilbara trap fishery is regulated by effort controls. The line fishery is currently unmanaged but is under review. Recreational catches are subject to bag and minimum size limits. Catches by all sectors (commercial and recreational) are included in the assessments of target species.

Future: Due to the continued decrease in catch rates of Rankin cod, especially in Area 5 of the trawl fishery, a 10% effort reduction will occur in Area 1 and also Area 5 in 2004. An equivalent effort reduction (7%) will occur across the whole of the trap fishery

The fishery will continue to be monitored by analysis of catch and effort data from logbooks, the CAES system and VMS. In 2004, the skipper’s logbook will be extended to collect additional data on catches and discards of target and non-retained species. It is proposed that an observer programme be developed whereby a bycatch assessment is conducted every 5 years.

Actions if Performance Limits are Exceeded: If performance measures are outside acceptable limits, a review will be conducted to determine the likely cause (e.g. market forces, other non-biological factors, recruitment, over-exploitation). If there is no evidence to suggest a decline in spawning biomass, then no action will be taken.

If the review suggests that performance limits were not met because of a decline in spawning stocks, the management response will be an adjustment of area-specific


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allocations of effort. This may include a reduction of total effort, area closures, or the redistribution of effort away from areas where over-exploited species are abundant and towards areas of high abundance of less vulnerable species.

Ability to implement these actions is provided through the FRMA and the Pilbara Fish Trawl Fishery Interim Management Plan 1997. The authority to adjust trawl effort is held by the Minister of Fisheries via authority to amend the Management Plan.

Effort adjustment in the trawl fishery would be accompanied by effort adjustment in the Pilbara trap fishery, where appropriate. Ability to implement action in the trap fishery is provided through the FRMA and the Pilbara Trap Fishery Management Plan 1992. The authority to adjust trap effort is held by the Executive Director of Fisheries.

Comments and Actions The long- lived species targeted by the trawl fishery are also taken by other sectors in the Pilbara region, particularly the trap and line fisheries. The line fishery is currently not formally managed, which is of particular concern in relation to goldband snapper stocks. Line catches of this species have increased considerably in recent years and were 20% of the total goldband snapper catch in the Pilbara in 2001.

A management plan for the wetline fishery is currently being developed, which will constrain the line catches of goldband snapper. The situations with goldband snapper highlights a general need to define catch shares of key species between fishing sectors. The Department of Fisheries is developing guidelines for catch sharing based on recent recommendations by Toohey et al. (2002). The increasing catches of goldband snapper in all sectors (trawl, trap and line) has been suggested by industry as a reason for undertaking a full stock assessment of this species. However, the poor quality of available catch rate data and the absence of age composition data would make full stock assessment of this species difficult.

External Driver Check List Commercial fishers in the Pilbara region have caught the major long- lived target species for a long time. Domestic market demand is strong and these species consistently fetch high prices. Improved marketing of fish that are presently discarded could increase the total catch of the fishery without a detrimental impact on the stocks of traditional target species.

In recent years, exclusion zones for gas pipelines and operations have reduced the area available for trawling. Seismic surveys also periodically restrict fishing activity. However, these operations are unlikely to significantly affect catch levels.

5.1.1.2 SHORT-LIVED SPECIES Rationale for Inclusion: Blue-spot emperor (Lethrinus hutchinsi), rosy threadfin bream (Nemipterus furcosus), flagfish (Lutjanus vitta) and frypan snapper (Argyrops spinifer) are the major short-


93

lived target species of the fishery. The fishery is capable of exerting a significant impact on the stocks of these species in the Pilbara region.

ERA Risk Rating: Impact on breeding stocks (C2 L6 MODERATE) These species have several life history traits in common – medium longevity, relatively rapid growth, high rate of natural mortality and young age of maturity – that make them less vulnerable to overfishing than the other, longer- lived target species. They are targeted primarily by trawl, but also caught by trap fishers in the Pilbara region.

Total spawning biomass across the whole region is considered adequate fo r each species, although there is evidence of localised depletion of blue-spot emperor in Area 1 of the fishery. In 2002, model estimates indicated the spawning biomass of blue-spot emperor was 40% of the virgin level in Area 1. The level of annual recruitment is unknown for this but there is no signal in the available age structure data for blue-spot emperor that would indicate large recruitment variation.

At the risk rating workshop in December 2002, there was some disagreement among participants as to the most appropriate levels of consequence and likelihood. The ratings eventually assigned to each of the short- lived target species differed among species. Blue-spot emperor was rated as C2 L6 MODERATE, threadfin bream and flagfish were rated as C1 L6 LOW, and frypan snapper was rated as C3 L4 MODERATE.

The outcome of each rating is either a full performance report or a full justification. In this report, all short- lived species have been assessed simultaneously, due to their similar life histories. The overall consequence is given as 'moderate' (level 2) and the likelihood is given as 'likely' (level 6), resulting in an overall risk rating of MODERATE. Therefore, a full performance report that includes all short-lived target species is presented.

Operational Objective To maintain the spawning stocks of blue-spot emperor, rosy threadfin bream, flagfish and frypan snapper at or above levels that minimises the risk of recruitment overfishing.

Justification: An operational objective that maintains the potenti al for recruitment at historical levels is consistent with the statutory obligation under section 3 of the FRMA (1994) "to conserve, develop and share fish resources of the State for the benefit of present and future generations." Indicators 1) Spawning biomass level of blue-spot emperor in Area 1;

2) Total annual catch level of each of the 4 major short-lived target species; and


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3) Total annual catch rate of each of the 4 major short- lived target species.

Blue-spot emperor is used as the indicator species to represent the short- lived target species in the fishery. Reliable catch and effort data is available for this species since 1993, although adequate data for modelling is only available in Area 1, where most of the blue-spot emperor catch occurs. The general success of management measures will be assessed by monitoring the catch levels and catch rates for each major short-lived target species, as well as the catch of blue-spot emperor.

Performance Measures 1) The median spawning biomass of blue-spot emperor should be above 40% of the 1993 spawning biomass in Area 1.

2) Annual catch of each short- lived target species should not increase > 20% above the average annual catch of the previous 4 years.

3) Annual catch rate of each short- lived target species should not decrease in two consecutive years.

Justification: Evidence from other fisheries suggests that a limit of 35%, with a target of 40%, of the virgin biomass is appropriate to ensure sustainability of the fishery (Mace 1994, Mace and Sissenwine 19 93, Die and Caddy 1997, Gabriel and Mace 1999). The spawning biomass of blue -spot emperor in 1993 is assumed to represent the virgin level. Biomass levels of < 40% tend to coincide with declining catch rates of short -lived target species. For example, in 2002, the age-structured stock assessment model suggested that blue -spot emperor was fully exploited in Area 1, where the spawning biomass was 40% of the virgin level. The catch and catch rate of blue -spot emperor declined in 2000 and 2001. Recent values of indicators are given in Table 14. Catch and catch rate indicators are consistent with the spawning biomass assessment of blue -spot emperor, which suggests that they are satisfactory measures of stock status. Table 14 Indicators for major short -lived target species. a) total estimated spawning biomass as percentage of virgin level; b) ratio of annual catch to average of annual catch in previous 4 years; c) ratio of annual catch rate to catch rate in previous year. Years in which these indicators would have triggered a review are shown.

Species a) Spawning biomass in 2002

b) Catch ratio 00 01 02

c) Catch rate ratio 00 01 02

Review? 01 02

Review if : < 40% > 1.20 < 1.0 in 2 consec. yrs

blue-spot emperor

> 40% 0.72 0.64 1.05 0.94 0.73 1.31 yes c no

flagfish n/a 0.86 0.91 1.36 0.92 0.95 1.49 yes c yes b


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frypan snapper n/a 0.46 0.51 1.14 0.79 0.86 1.31 yes c no

threadfin bream n/a 0.76 0.90 1.91 0.90 1.12 1.93 no yes b

Data Requirement for Indicator Data Required Availability

Catch & effort by trawl fishery

Monthly or trip summaries of trawl catch (by species) & fishing effort (in days). Compiled by licensees & stored in CAES system. Available since 1989.

Voluntary skippers logbooks. Shot-by-shot estimates of trawl time, location & catch by species. Available since 1993 for target species only.


Catch & effort by trap fishery

Monthly or trip summaries of trap catch (by species) & effort (days, number of traps). Compiled by licensees & stored in CAES system. Available since 1985.

VMS – monitors trap fishing location & effort. Operational since 2000.

Catch by line fishery Monthly summaries of line catch (by species) compiled by licensees & stored in CAES system. Available since 1985.


Occasional recreational catch surveys. Last survey of Pilbara was conducted 1999-2000.

Catch & effort by charter boat fishery

Compulsory logbooks. Trip summaries of catch & effort. Compiled by fishers. Available since 2001.

Age structure data Age structure data for blue-spot emperor, collected every 4 yr, would improve quality of assessments.

Data not currently being collected.

Evaluation Summary: The level of spawning biomass of blue -spot emperor is estimated to be satisfactory over the whole fishery, although there appears to be local depletion in Area 1. Biomass estimates for other species are not available but stable or increasing catch rates of rosy threadfin bream and flagfish in recent years suggest that spawning biomass levels are adequate for these species. Catch rates of frypan snapper have been decreasing, but this is more likely to be due to market demand and fishing practices than decreasing stock size.


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Catch: The trawl fishery catch of the short- lived target species landed in 2002 (2001 catch in brackets) were threadfin bream 363 t (228 t), blue spot emperor 353 t (318 t), flagfish 211 t (171 t), and frypan snapper 42 t (42 t). The catches of all these species decreased from 1998 to 2001, but increased in 2002.

Results of the recent Bycatch Survey of the fishery suggested that approximately 0.1 t of flagfish, 0.8 t of blue-spot emperor and 57 t of threadfin bream are discarded per year (Stephenson and Chidlow 2003). There is significant discarding of rosy threadfin bream because they are sometimes discoloured or crushed during capture. However, at the current levels of effort, the fishing mortality of rosy threadfin bream is lower than any other target species (Stephenson and Dunk 1996) and discards would have a negligible impact on the stock of this species. There is little discarding of blue-spot emperor, flagfish or frypan snapper, as the small individuals are generally not captured, or can be avoided by fishers.

In 2002 (2001, in brackets), trap fishers in the Pilbara region caught 57 t (43 t) of blue-spot emperor, 3 t (4 t) of flagfish and 1 t (1 t) of frypan snapper.

Effort: The measure of effort used to calculate catch rate is 'VMS hours', i.e. hours spent within the boundaries of the fishery as measured by VMS. An anticipated increase in fishing efficiency is likely to cause catch rates calculated from this nominal effort (i.e. unadjusted effort) to become progressively less indicative of decreases in stock size. Efficiency increases in the fishery have not been quantified. However, to provide a more realistic estimate of catch rate from 1994 to 2000, a modest increase in efficiency of 2% per year was incorporated into biomass modelling. Zero efficiency increase was assumed in 2001.

Catch rates: After 1998, total effort in the fishery was reduced and redistributed among Areas to reduce fishing pressure on vulnerable target species. The catch rates (using nominal effort) of blue-spot emperor, rosy threadfin bream and flagfish have been stable from 1998 to 2001, with an increase in 2002. The catch rate of frypan snapper declined from 1998 to 2000 but was stable in 2001 and 2002 (Figure 8).

Recreational component: A recent creel survey of boat and shore-based recreational fishing between Exmouth and Broome in 1999-2000 indicated that these fishers do not catch significant quantities of blue-spot emperor, rosy threadfin bream, flagfish or frypan snapper in the Pilbara region (Williamson et al. in prep).

Stock assessment: Trap and line catches are included in the stock assessment of each short- lived target species. However, trap and line catches of these species are low relative to catches by the trawl fishery.

Using the indicators as described above, three of the major short- lived target species (i.e. blue-spot emperor, flagfish and frypan snapper) triggered a review in 2001, and two (flagfish and threadfin bream) triggered a review in 2002 (Table 14).

A stock assessment of the short-lived species (Stephenson and Dunk 1996) indicated that rosy threadfin bream, and flagfish were under exploited, and that blue-spot emperor catches were sustainable overall. However, there was some concern that there could, in the future, be local depletion of blue-spot emperor in the west of the fishery. After this assessment, there were significant effort reductions in Area 1 in 1998 and 1999 and 2001. The model estimate of the spawning biomass of blue-spot


97

emperor in Area 1 (Figure 12) indicated that that it was at 41% of the 1983 level in 2002, but likely to decline at the present level of effort.

Figure 12. Spawning biomass (with 95% confidence intervals) in Area 1 as a percentage of the 1993 level (black line); the biological reference point (40% of the 1993 level – dotted line); and the catch from all fishing sectors (columns) for blue-spot emperor in the Pilbara fishery. Data from 2003 onwards is projected from the model.

The catch levels of threadfin bream and flagfish increased markedly in 2002, and resulted in the triggering of indictors for these species. However, catch rates did not decline and spawning biomass levels of these species are considered adequate. The fishery does not target these species and most catches are incidental. Higher catches probably reflected an increase in abundance, either due to fish movement or recruitment. The catch level and catch rate of frypan snapper gradually declined between 1996 and 2002. The fishery does not heavily target this species and so catches tend to be incidental. The reasons for the decline in frypan snapper catches are unclear and this species should be monitored closely in future.

Robustness: High The estimates and limits are considered highly robust because they are based on:

• data calculated from several medium-term fishery-dependent and independent data sources.

• catch and effort data that are validated by cross-referencing between CAES, logbook and VMS sources.

• research methods that have been reviewed and published in scientific literature.

• estimates of biomass on an area-specific basis.

Pilbara Spawning Biomass and Catchblue-spot emperor

0

20

40

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1993 1995 1997 1999 2001 2003 2005 2007 2009

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irg

in S

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• data of a statistically demonstrated high level of confidence.

Fisheries Management Response Current: The fishery is managed through effort controls and gear restrictions. Area-specific amounts of effort units are allocated to each licensee. There are 11 licences in the fishery, but an equivalent of only 4.3 full time vessels are currently operating. The value of an effort unit is reviewed annually and can be adjusted to change total or area-specific effort levels as required. Area 3 is closed to trawl and trap fishing and Area 6 is closed to trawl fishing.

The Pilbara trap fishery takes minor quantities of some short- lived target species, mainly blue-spot emperor and red snapper. The Pilbara trap fishery is regulated by effort controls.

Catches by all sectors (commercial and recreational) are included in the assessments of target species. However, the trawl fishery catches the vast majority of these short-lived species. Therefore, the status of these stocks is likely to be mainly influenced by management action in the trawl fishery.

Future: The downward trend in the catch model spawning biomass of blue-spot emperor in Area 1 and the local depletion of Rankin cod in Area 5 led to a 10% effort reduction in Areas 1 and 5 in 2003.

The fishery will continue to be monitored by analysis of catch and effort data from logbooks, the CAES system and VMS. In 2004, the skipper’s logbook will be extended to collect additional data on catches and discards of target and non-retained species. It is proposed that an observer programme be developed whereby a bycatch assessment is conducted every 5 years.

Actions if Performance Limits are Exceeded: If performance measures are outside acceptable limits, a review will be conducted to determine the likely cause (e.g. market forces, other non-biological factors, recruitment, over-exploitation). If there is no evidence to suggest a decline in spawning biomass, then no action will be taken.

If the review suggests that performance limits were exceeded because of a decline in spawning biomass, the management response will be an adjustment of area-specific allocations of effort. This may include a reduction of total effort, area closures, or the redis tribution of effort away from areas where over-exploited species are abundant and towards areas of high abundance of less vulnerable species.


Effort adjustment in the trawl fishery would be accompanied by effort adjustment in the Pilbara trap fishery, where appropriate. Ability to implement action in the trap fishery is provided through the FRMA and the Pilbara Trap Fishery Management Plan 1992. The authority to adjust trap effort is held by the Executive Director of Fisheries.


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Comments and Actions The catch levels of each short- lived species are likely to be sustainable at current levels of effort. There is potential for increased catches of each species except blue-spot emperor, which may be over-exploited in Area 1 despite the modest effort reduction in 2003.

It would be of economic benefit to the fishery if catches of some short lived species like flagfish and rosy threadfin bream increased, provided there was not an increase in the catches of the long- lived species.

External Driver Check List In recent years, exclusion zones for gas pipelines and operations have reduced the area available for trawling. Seismic surveys also periodically restrict fishing activity. However, these operations are unlikely to significantly affect catch levels.

5.1.2 BY-PRODUCT SPECIES 5.1.2.1 OTHER SCALEFISH Rationale for Inclusion: Approximately 37 taxa, of other scalefish (i.e. species caught in addition to those listed above as primary target species) are reported on monthly returns by the fishery.

ERA Risk Rating: Impact on breeding stocks of other finfish (C1 L6 LOW) Scalefish species that are likely to be vulnerable to over-fishing can be identified by certain life history traits, including slow growth, low natural mortality, low fecundity, low dispersal, limited species distribution, narrow habitat or dietary requirements. Species with these characteristics include those listed above as long- lived target species. Many species that comprise the catch of 'other scalefish' do not share these characteristics, and so are unlikely to be vulnerable to overfishing.

The area of the trawl fishery in which 'other scalefish' are taken is small relative to the total distributions of each species. Also, the quantities of each species of 'other scalefish' taken by this fishery are minor and unlikely to deplete these stocks. Therefore, it was considered 'likely' that the fishery will have a 'minor' impact on the populations of 'other finfish'. This resulted in a risk rating of LOW.

The total annual reported catch of 'other scalefish' by the fishery ranged from 767 t to 1140 between 1998 and 2002. In 2002, the reported catch (767 t) of 'other scalefish' represented 31% of the total PFTIMF catch, and 33% of the total PFTIMF scalefish catch. Reported catches of individual species were between 0 and 138 t (Table 15).


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Table 15 Catches of all species reported by the PFTIMF, and total Western Australian (WA) state catch by all fisheries in 2002.

Common Name Scientific Name

Rosy threadfin bream Nemipterus furcosus 363.1 363.1 100 T Blue-spot emperor Lethrinus hutchinsi 352.9 407.1 87 T Red snapper Lutjanus erythropterus 278.5 325.8 85 T Flagfish Lutjanus vitta 210.8 212.5 99 T Trevally Carangidae 138.0 193.8 71 Red mullet Mullidae 108.8 108.8 100 Jobfish/goldband snapper Pristipomoides multidens # 98.6 513.7 19 T Scarlet perch Lutjanus malabaricus 81.9 162.4 50 T Red emperor Lutjanus sebae 79.4 243.3 33 T Red spot emperor Lethrinus lentjan 74.7 75.1 99 Bigeye Priacanthus macracanthus 65.9 66.0 100 Robinson's seabream Gymnocranius grandoculis 50.2 51.9 97 Frypan snapper Argyrops spinifer 42.2 42.1 100 T Moses perch Lutjanus russelli 41.6 48.8 85 Sand snapper Diagramma labiosum 28.2 80.3 35 Pearl perch Glaucosoma buergeri 26.1 38.0 68 Lined javelinfish Hapalogenys kishinouyei 21.3 21.6 99 Cobia Rachycentron canadus 19.9 35.3 56 Spotted cod Epinephelus areolatus, E. bilobatus, E.microdon 19.8 33.5 59 Spangled emperor Lethrinus nebulosus 19.4 188.9 10 T Rankin cod Epinephelus multinotatus 17.0 58.0 29 T Catfish Ariidae 16.2 18.8 86 Mulloway Protonibea diacanthus # 14.0 78.6 18 Mangrove jack Lutjanus argentimaculatus 13.7 15.9 86 Cod Serranidae 13.0 93.5 14 Fortescue Siganus lineatus 11.9 11.9 100 Tuskfish Choerodon spp 10.2 11.8 86 Leatherjacket Paramonacanthus spp 10.1 64.7 16 Chinaman fish Symphorus nematophorus 10.0 11.1 91 Parrotfish Scaridae 8.2 9.7 84 Samson fish Seriola hippos 7.0 109.7 6 Monocle bream Scolopsis spp 7.0 7.0 100 Maroon seaperch Lutjanus lemniscatus 7.0 11.8 59 Longnose emperor Lethrinus olivaceus 6.5 17.1 38 Coral trout Plectropomus maculatus # 4.8 22.5 21 Golden trevally Gnathanodon speciosus 4.2 6.2 67 Five-lined seaperch Lutjanus quinquelineatus 3.9 6.8 58 Halibut Psettodes erumei 3.9 5.8 67 Surgeon fish Acanthuridae, Zanclidae 3.2 3.2 100 Black pomfret Parastromateus niger 3.1 3.1 99 Chinaman cod Epinephelus rivulatus 1.3 4.6 28 Wrasse Labridae 0.9 9.5 9 Barracuda Sphyraenidae 0.9 2.9 29 Mackerel Scombridae 0.4 498.6 < 1 Fusilier Caesio and Pterocaesio spp 0.4 0.4 100 Estuary cod Epinephelus coioides 0.4 0.4 100 Foxfish Bodianus spp 0.1 1.1 6 Other scalefish 9.9 136.1 7 Sharks 68.3 1901.8 4 Cuttlefish Sepiidae 104.2 125.8 83 Squid Teuthoidea 2.5 81.2 3 Bugs Scyllaridae 5.4 38.2 14 Total catch 2492.8 6579.5 38 (# only species caught by PTWT shown, but total WA catch includes additional species) (T = target species)

PFTF catch (t)

Total WA catch (t)

PFTF catch (% of WA catch)


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5.1.2.2 ELASMOBRANCHS Rationale for Inclusion: Twenty four species of sharks and 10 species of rays are known to be caught by the PFTIMF. Of these, 14 species of sharks and 3 species of rays are known to be retained in small quantities as byproduct. Generally, only large individuals of any species are retained.

ERA Risk Rating: Impact on breeding stocks (C3 L4 MODERATE) Sandbar shark, Carcharhinus plumbeus, is one of the main shark byproduct species in the fishery. Sandbar sharks, and most other species of shark, have a highly K-selected life history (i.e. long- lived, slow growth, low reproductive potential). Such species are highly susceptible to overfishing and may take many generations to recover. Therefore a potential consequence rating of 'severe' was applied.

Sandbar shark is the primary component of the catch of the WCDGDLF and the NCSF and is also caught as a byproduct species in several State and Commonwealth-managed fisheries. These fisheries also catch some other species of sharks that may be caught in minor quantities in the trawl fishery. The quantities of sandbar shark and other sharks caught as byproduct by the PFTIMF are relatively minor compared with catches of the dedicated shark fisheries. This suggests that the impact of the trawl fishery on shark populations is minor. However, there is some uncertainty about the true level of exploitation of each shark species because sharks caught as byproduct by the trawl fishery are generally not reported by species. Also, only 2 of the shark species (sandbar and dusky sharks) likely to be caught by the fishery have been formally assessed. Therefore, due to this uncertainty, a likelihood rating of 'possible' was applied. This resulted in a risk rating of 'MODERATE'.

A brief report to assess the performance of the PFTIMF in relation to sharks is presented here. More comprehensive performance reports for each major shark species are given in the ecological assessments of the Joint Authority Southern Demersal Gillnet and Demersal Dropline Fishery (JASDGDLF) and the WCDGDLF and the ecological assessment of the NCSF. These fisheries catch the vast majority of sharks in WA.

Operational Objective To maintain the breeding stocks of sandbar shark, and other shark species, at or above levels that minimise the risk of recruitment overfishing.

Justification: An operational objective that maintains the po tential for recruitment at historical levels is consistent with the statutory obligation under section 3 of the FRMA "to conserve, develop and share fish resources of the State for the benefit of present and future generations."


102

Indicator 1) Level of total shark catch.

Quantities of sharks caught by the fishery are not currently reported by species. Therefore it is not possible to directly monitor the catch level of individual species. It is only possible to monitor the total shark catch.

2) Catch level of selected target species.

In future, catches of sandbar shark and other selected shark species should be reported by species.

Performance Measure 1) The total, annual retained catch of sharks should not increase by > 100% of the average of the annual catch from 1995/96 to 2001/02 (i.e. 64 t) in 2 consecutive years.

2) From 2004 to 2009, the proportion of shark catch that is reported by species should increase annually.

Justification: This performance measure is intended to maintain the shark catch of t he fishery at the current level, which is minor compared with the total state catch. The range of annual variation (i.e. 100%) is broad because, at such low levels, minor changes in actual catch will appear as major fluctuations. Also, the broad range reflects the considerable uncertainty associated with the catch data for sharks, which arises because of misidentifications and varying levels of unreported discards. This performance measure is intended to improve the quality of reporting of shark catches. Catches of each species are required to assess stock status. This is particularly important for sandbar shark. The Department of Fisheries has recently published an identification guide (McAuley et al. 2002) to assist commercial fishers in identifying shark s to species level. Data Requirement for Indicator 1) 'Total annual shark catch' is required from the trawl fishery. Trawl fishers provide monthly catch returns that summarise retained catches of sharks by trip. These data are available since 1989 and are stored in the CAES database.

2) Catch summaries of sandbar shark and other selected species.

Evaluation Summary: No estimates of breeding stock biomass are available for any of the shark species taken as byproduct by the fishery. However, preliminary estimates of the exploitation rates of sandbar shark have been assessed as sustainable, as determined from a study of tag recaptures. Sandbar shark is the major target


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species in the region, but it has only recently become the primary target species in the WCDGDLF and the NCSF, and severe stock depletion is unlikely to have occurred yet. The low quantities of each species, including sandbar shark, caught by the PFTIMF are unlikely to have a significant impact on breeding stock biomass of any species.

Catch: Between 1995/96 and 2001/02, the total annual retained catch of sharks by the fishery ranged from 41 to 79 t (Figure 13). In 2001, the total catch of sharks and rays was 73 t, which contributed approximately 3% of the total fishery production. This catch was approximately 19% of the total annual shark production for the North Coast Bioregion and approximately 4% of the total annual shark production for the state. In 2002, the shark/ray catch was 69 t.

Figure 13. Annual retained catch of sharks by the PFTIMF and total annual catch of sharks in WA (all fisheries), 1985-86 to 2000-01.

The quantity and type of sharks that are retained by the fish trawl fishery varies considerably among vessels. Between 0 and 80% of sharks caught may be retained, depending on the vessel. Usually, larger sharks are retained and smaller sharks are discarded. However, the decision to retain or discard a shark is affected by marketability and vessel storage capacity. Small sharks are likely to suffer higher mortality from discarding than large sharks.

The catches of each shark species cannot be determined directly from CAES system data because shark catches are not reported by species. The 2002 Bycatch Survey (Stephenson and Chidlow 2003) estimated the species composition of the shark catch in the fishery. To estimate specific annual catches each year, the proportions of each species observed during the survey are applied to the total annual reported shark catch (Table 16). These estimates are approximate, due to the limited amount of survey data, and probably do not precisely reflect annual catches. In particular, catches of sandbar shark are generally expected to be higher than other species. Some sandbar shark caught during the survey were tagged and released, but would otherwise have been retained by the fishery. Hence, the annual catch estimate for sandbar shark is probably approximately twice (i.e. 26 t) the estimate presented in Table 16.

0

500

1000

1500

2000

2500

1985

-86

1986

-87

1987

-88

1988

-89

1989

-90

1990

-91

1991

-92

1992

-93

1993

-94

1994

-95

1995

-96

1996

-97

1997

-98

1998

-99

1999

-00

2000

-01

2001

-02 0

20

40

60

80

Total WA

Pilbara fish trawl

Year

Pilbaracatch (t)

Tot

al W

A c

atch

(t)

0

500

1000

1500

2000

2500

1985

-86

1986

-87

1987

-88

1988

-89

1989

-90

1990

-91

1991

-92

1992

-93

1993

-94

1994

-95

1995

-96

1996

-97

1997

-98

1998

-99

1999

-00

2000

-01

2001

-02 0

20

40

60

80

Total WA

Pilbara fish trawl

Year

Pilbaracatch (t)

Tot

al W

A c

atch

(t)


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Table 16 Shark species retained during the 2002 bycatch survey and estimated retained catches of each species by the PFTIMF fishery in 2002 (estimated by applying survey proportions to the total retained catch of 69 t).

Species Survey catch (%) PFTF catch (t)

Pigeye shark (Carcharhinus amboinensis) 23 16

Sandbar shark (Carcharhinus plumbeus) 19 13

White-spot guitarfish (Rhynchobatus djiddensis) 15 10

Great hammerhead shark (Sphyna mokarran) 12 8

Blacktip shark (Carcharhinus tilstoni/limbatus) 9 6

Tiger shark (Galeocerdo cuvier) 5 4

Shovelnose ray (Rhinobatos sp.) 4 3

Fossil shark (Hemipristis cuspidata) 2 2

Milk shark (Rhizoprionodon acutus) 1 1

Other species 1 1

Other commercial fisheries: The NCSF operates in the Pilbara and Kimberley regions. The shark catch by this fishery was 288 t in 2000/01, including 79 t of sandbar shark. The 'wetline' catch (i.e. catches from commercial fishers not operating within the managed fisheries) of sharks in the North Coast Bioregion was 19 t in 2000/01.

The WCDGDLF operates to the south of the PFTF. It caught 322 t of shark in 2000/01, including 131 t of sandbar shark.

The other major producer of shark in Western Australia is the JASDGDLF, which caught 811 t of shark in 2000/01, including 22 t of sandbar shark. However, the catch of this fishery is mainly comprised of different species to those caught in the Pilbara region.

Recreational fishery: The recreational catch of sharks in the West Coast Bioregion was estimated to be 15-20 t in 2001. The recreational catch of sharks in the Pilbara region has not been estimated but is likely to be lower than the West Coast catch because fishing effort in the Pilbara is lower. Recreational fishing effort in the Pilbara is low, relative to the West Coast Bioregion. Also, gear used by recreational fishers in the Pilbara is relatively 'light' and not effective in retaining large sharks, which are particularly abundant in the northern bioregion.

Robustness: Low 1) 'Total shark catch' by the fishery is a poor indicator of changes in shark stock size because it provides no information about changes in the catches of individual species. However, it is likely to be a reasonable indicator of changes in fishing practices that affect sharks.


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2) Catches of individual species, including sandbar shark, from the trawl fishery will be included in stock assessments of major target species in the dedicated shark fisheries. This will improve the robustness of assessments (see JASDGDLF and WCDGDLF Ecological Assessment Report and the NCSF Ecological Assessment Report for details of stock assessments).

Fisheries Management Response Current: The PFTF is primarily managed through area-based effort control. Area-specific amounts of effort units are allocated to each licensee. There are 11 licences in the fishery, but an equivalent of only 4 full time vessels are currently operating. The value of an effort unit can be adjusted annually to change total or area-specific effort levels as required. Zone 1 and Areas 3 and 6 are completely closed to trawling. Trawl fishers are permitted to retain sharks as byproduct. However, both fins and trunks must be retained.

The JASDGDLF, WCDGDLF and NCSF are limited access fisheries and are managed through effort control (time/gear units of effort). The JASDGDLF was declared a limited entry fishery in 1988. Time/gear restrictions were first introduced in this fishery in 1993 and various additional measures have since been added to further reduce effort. The WCDGDLF has been managed by spatial closures since 1993 and by time/gear restrictions since 1997, and was declared a limited entry fishery in 2000.

The NCSF, which includes the WA North Coast Shark fishery and the Joint Authority Northern Shark Fishery (joint authority between Commonwealth and state) has been managed by gear restrictions since 1993. The NCSF has 13 licenced vessels, although only 7 were active in 2000/01 and only 3 reported fishing in > 6 months of the year.

All commercial fisheries that retain sharks operate under "finning" regulations, which stipulate that both fins and trunk must be retained.

Recreational fishers in Western Australia are subject to a mixed species bag limit of 2 (west coast and Gascoyne regions) or 4 (north and south coast regions) sharks.

Future: An updated demographic analysis and an age-structured model of sandbar shark are currently being developed by the Department of Fisheries.

The Department will investigate the use of skippers logbooks to record catch and discard data on selected shark species. However, the success of this measure is dependent on fishers being able to identify sharks accurately. The Department recently published an identification guide (McAuley et al. 2002) to assist commercial fishers in identifying sharks to species level. It is proposed that a bycatch survey of the fishery be conducted every 5 years, which would include collection of data on shark species composition.

It is proposed that a Code of Conduct be developed by industry to promote appropriate handling practises that minimise the mortality of released sharks and maximise the value of retained shark byproduct.

Actions if Performance Limits are Exceeded: If the catch limit is exceeded, a review will be conducted to determine whether a change in fishing practices due to market forces, effort adjustment or other non-biological factor is responsible. The


106

outcome of this review will be considered in conjunction with the results of the stock assessments undertaken in the managed shark fisheries.

If there is evidence of a stock decline, the Department of Fisheries will undertake actions, as outlined in the JASDGDLF and WCDGDLF Ecological Assessment Report and the NCSF Ecological Assessment Report, as appropriate for each species. Within the fish trawl fishery, there is potential to reduce catches of large sharks. With appropriate handling, the likelihood of survival after release of large sharks is high. Alternatively, escape grids could be installed at the entrance to the cod ends of trawl nets to reduce the bycatch of sharks. However, this measure would be largely ineffective as it would not reduce the catch of smaller sharks, which would probably pass through the grid (Stephenson and Chidlow 2003).


Comments and Actions Sharks are slow to reproduce and many are relatively long- lived and. Consequently, a delay of several years may occur between the implementation and observable effect of any management action.

External Driver Check List Sharks are primarily retained for the value of their fins. Larger sharks are usually retained in preference to small sharks because of higher fin value. Sandbar sharks are often retained because they have large fins, relative to their body size. Fins are exported to South East Asia and so export market forces mainly influence the value of shark by-product.

5.1.2.3 BUGS Rationale for Inclusion: Bugs (Thenus orientalis) are caught and retained as by-product by the fishery.

ERA Risk Rating: Impact on breeding stocks (C1 L2 LOW) The area of the trawl fishery in which bugs are taken is small relative to the total distribution of this species. Therefore it was considered that the fishery could have a 'minor' impact on the population size, with no impact on population dynamics, and this impact was likely to be 'rare'. This resulted in a risk rating of LOW.

Bugs have a wide geographic range across northern Australia, from Shark Bay, WA, northwards to Coffs Harbour, NSW. They have a 3-month offshore larval stage, which allows them to disperse widely and is probably responsible for a single genetic stock (Kailola et al. 1993). Also, adults are highly mobile and can move distances up to 50 nautical miles. Bugs reach maturity in 1-2 years, at approximately 52 mm


107

carapace length. Females commonly spawn at least twice per season, with a minimum of 3 months between spawnings. The spawning season is extended and peaks in spring. Eggs are incubated by females and brood sizes ranges from 4000 to 25000 eggs. Bugs remain buried in sediment during day and become active at night. They prey on fish, crustaceans, molluscs (especially bivalves) and are consumed by demersal fish and rays. They may live in excess of 7 years and reach 75 mm carapace length.

Bugs mostly occur in the shallower (50-65 m depth) waters of the trawl fishery but may occur to 200 m (Wadley and Evans 1991). Their distribution also includes waters inshore of the fishery (30-50 m depth) and areas of rough ground within the fishery where they are not subject to trawling.

The annual catch of bugs by the trawl fishery ranged from 3 to 7 t between 1998 and 2002. In 2002, the catch was 5 t, which represented 14% of the total WA state catch (38 t) of bugs. The Exmouth Gulf, Onslow, Nickol Bay and Kimberley prawn fisheries also catch minor quantities of bugs in Western Australia.

It is proposed that a Code of Conduct be developed by industry to promote the release juveniles and berried female bugs.

5.1.2.4 CEPHALOPODS Rationale for Inclusion: Pharaohs cuttlefish (Sepia pharaonis) and squid (Family: Loliginidae) are retained as byproduct by the fishery. Squid are caught in very minor quantities.

ERA Risk Rating: Impact on breeding stocks (C1 L2 LOW) The area of the trawl fishery in which cuttlefish and squid are taken is small relative to the total distribution of each species. Also, the quantities retained by the fishery are small relative to the likely stock size of each species. Therefore it was considered that the fishery could have a 'minor' impact on the population size, with no impact on population dynamics, and that any impact was likely to be 'rare' for each species. This resulted in a risk rating of LOW.

Pharaohs cuttlefish is distributed across northern Australia and throughout the Indo-Pacific, north to Japan. In Western Australia, it occurs as far south as Rottnest Island. The species occurs to depths of 110 m but is most common from the surface to 40 m depth (Wadley and Dunning 1998). Adults migrate shoreward and aggregate when spawning. Hence, much of the distribution of this species, including spawning areas, is located inshore of the trawl grounds and is not subject to trawl fishing.

Various species of loliginid squid may be caught by the fishery, including northern calamari (Sepioteuthis lessoniana), mitre squid (Loligo chinensis) and north-west squid (L. edulis). Each species occurs in coastal and shelf waters of northern Australia (Kailola et al. 1993). Mitre and north-west pink squid occur throughout the western Pacific and northwards to Japan. Northern calamari are widely distributed throughout the Indo-Pacific, from Africa to Hawaii and northwards to Japan. In Western Australia, each species occurs south as far as Shark Bay. Spawning is poorly


108

understood in these species but adults probably migrate shoreward to spawn and spawning may occur throughout the year.

A significant proportion of the cuttlefish and squid populations in the Pilbara region are not vulnerable to trawling because they occur in habitats where demersal trawling does not occur. Cuttlefish are typically associated with structured habitats, such as reefs and seagrass, which are not trawled. Loliginid squid range over the bottom, but also migrate into the water column where they are not subject to trawling. Closed areas within the fishery (Zone 1, Areas 3 and 6) provide additional refugia for each species.

In general, cuttlefish and squid have a low susceptibility to overfishing because they grow rapidly and have a very high rate of natural mortality. Mass mortalities occur after spawning. Pharaohs cuttlefish reach at least 26 cm mantle length and the life cycle is less than 10 months in captive animals (Norman 2000). Loliginid squid typically live for 1-2 years and mature after 1 year or less (Dunning and Lu 1998).

Cuttlefish were heavily exploited by Taiwanese trawlers on the north-west shelf, with peak landings of >8400 t in 1982 (Kailola et al. 1993). By comparison, recent cuttlefish catches in Western Australia have been relatively small, with a total of 59 t reported in 2001 and 126 t in 2002. In the PFTF, annual catches ranged from 22 to 104 t between 1998 and 2002. The catch in 2002 (104 t) represented 83% of the total WA state catch.

The standing stock of loliginid squids on the north-west shelf has been estimated at 4500 t (Lui and Yeh 1984). By comparison, recent catches of squid in Western Australia have been small, with a total of 48 t reported in 2001. Approximately 2.5 t of squid was caught and retained by the PFTIM in 2002. This catch represented 3% of the total WA state catch. The low trawl catch is partly due to the selectivity of the 100 mm mesh used in fish trawl nets, which does not effectively retain small squid.

At the risk rating workshop in December, 2002, octopus was suggested as another minor byproduct species. However, subsequent inspection of CAES data failed to find any significant catches of octopus by the fishery in recent years.

5.1.2.5 SHELLS Rationale for Inclusion: Various species of shells (Gastropoda) are caught by the fishery and some are retained as by-product.

ERA Risk Rating: Impact on breeding stocks of shells (C1 L6 LOW) Shells are incidentally caught by the fishery. Some larger shells are retained by the crew for personal use or sold to collectors. The composition of the shell catch is unknown. The 2002 Bycatch Survey (Stephenson and Chidlow 2003) caught 30 "conch" shells (Turbinellidae) and 20 "bailer" shells (Volutidae) in 427 trawl shots. All individuals were alive when landed. Discarded shells have a high probability of survival after capture and release by the fishery.


109

At the risk rating workshop in December 2001, it was considered 'possible' that the fishery could have a 'severe' impact on the stocks of shells. However, lack of background information about shells at the meeting was noted as a difficulty in rating this issue. Better documentation was requested. A subsequent review of available literature (see below and Background section) suggested that the fishery was 'likely' to have a 'minor' impact on breeding populations of deepwater shell species. This resulted in a risk rating of LOW.

Specimen shell collection in WA is restricted to the 34 licensees of the Specimen Shell Managed Fishery, who operate under the Specimen Shell Management Plan. This fishery is managed by restrictions on vessel size and fishing methods, and operates along the entire Western Australian coastline, subject to specific closures (e.g. within some marine parks and aquatic reserves).

However, shells are also caught and retained as byproduct by prawn and fish trawl fisheries. Trawl fishers, including those in the Pilbara, are not licenced to collect shells. Yet small quantities of shells have historically been retained as byproduct by the fishery and this practice currently continues.

Total quantities of shells retained by the PFTIMF are low. Also, the area of the trawl fishery in which shells can be taken is small relative to the total range of each species. Therefore, the impact of the fishery on each retained species is likely to be minor. Within the fishery, potential shell habitats include areas of rough ground and closed areas (Zone 1, Areas 3 and 6). These areas are not subject to trawling and so provide refugia for shells.

The shells taken by fish trawling are deep water species. They are generally different to those species taken by Specimen Shell fishery licensees, who are restricted to diving and hand collecting and therefore can only collect shallow water species. Shells collected by fish trawling are not typically of high quality, but fetch reasonable prices because of their rarity on the market. This rarity is due to the difficulty of deepwater collection and is not a reflection of low abundance. The shells caught during the recent Bycatch Survey were not fully identified and may have comprised up to 6 different species. The volute catch included individuals of Melo sp., probably M. umbilicatus (Volutinidae), and individuals tentatively identified as Syrinx aruanus (Turbinellidae). The Specimen Shell fishery reported collecting zero M. umbilicatus and 2 S. aruanus in 2002.

In 2000/01, licensees in the Specimen Shell fishery reported a total catch of 20138 shells. The reported catch comprises over 460 species. Of these, only six species of cowries (Cypraeidae) - Cypraea friendlii vercoi, C. marginata (albanyensis), C. marginata (consueta), C. rosselli, C. reevii and C. venusta - and 2 species of volutes (Volutidae) – Amoria damoni (keatsiana) and A. damoni (reevi) - have been identified as vulnerable to over-exploitation (Ponder and Grayson 1998, Wells 2002). The Specimen Shell fishery collects between 50 and 600 individuals of each species per year. The trawl fishery does not collect these vulnerable species.

Action: Although the impact on shell stocks by the fishery is probably minimal, the performance of the fishery in regard to bycatch of shells could be improved. Trawl fishers are not licenced to retain shells and yet this practice is widespread. Regulations regarding shell collection by trawl fishers need to be clarified. In future, if trawl fishers are endorsed to retain shells as byproduct, then catches will be reported on monthly Specimen Shell Managed Fishery returns.


110

It is proposed that a bycatch survey of the fishery be conducted every 5 years, which would include collection of data on shell species composition. It is proposed that a Code of Conduct be developed by industry to promote appropriate handling practises and the release of shells by fishers without a licence to retain them. Released shells are expected to have a high rate of survival.

A full performance report on the impact of shell collecting, including shells taken by the PFTIMF, will be part of the ecological assessment of the Specimen Shell Managed Fishery.


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5.2 NON-RETAINED SPECIES

COMPONENT TREE FOR THE NON-RETAINED SPECIES IN THE PFTIMF

Dolphins

Turtles

Sea snakes

Sawfish

Sygnathids

Protected species

Morey eels

Unmarketable scalefish

Elasmobranchs

Macro-invertebrates

Other

Capture

Benthic organisms

Direct Interaction but no capture

Non Retained Species

A yellow box indicates that the issue was considered a high enough risk at the December 2002 Risk Assessment workshop to warrant a full performance report. A blue box indicates that the issue was considered a low risk, with no specific management required, and only a justification is presented.

5.2.1 PROTECTED/LISTED SPECIES 5.2.1.1 DOLPHINS Rationale for Inclusion: Dolphins are known to be caught by the fishery.

ERA Risk Rating: Impact on breeding stock (C2 L6 MODERATE) The 2002 Bycatch Survey (Stephenson and Chidlow 2003) caught 4 bottlenose dolphins (Tursiops truncates) during 427 trawl shots. All were dead. Data from the survey and anecdotal information suggest that between 50 and 100 dolphins may be killed by the fishery per year. No estimate of population size is available for the Pilbara region but bottlenose dolphins occur in tropical and temperate waters around the world and are common across northern Australia. Bottlenose dolphins are not thought to be in danger of local extinction. Fish trawl fisheries have operated in the Pilbara region since the 1960s. Yet bottlenose dolphins are common in the Pilbara region, which suggests that the impact of trawling on the local dolphin population is


112

relatively low. 10-40 dolphins are observed in the vicinity of the trawl on most trips. Therefore, the fishery probably exerts a minimal impact on the stock. However, it was considered that this impact was at the maximum acceptable level (level 2) in most circumstances (level 6), given the protected status of the species. This resulted in a risk rating of MODERATE.

Operational Objectives To minimise the incidental capture of dolphins by at least 50% following the implementation of mitigation measures (and supporting legislation and policy). To maximise the accuracy of reporting of incidental captures.

Justification: Dolphins are a protected species and impacts resulting from the operations of the fishery should be managed. As a protected specie s, all incidental captures must be reported. Indicators 1) Number of dolphins caught and their condition at release.

2) Compliance by skippers with requirements to report all details of dolphin captures.

Performance Measure 1) Number of dolphins caught by the fishery should be less than 75 per year, assuming 100% catch mortality.

2) All skippers to maintain records of the time, date, shot duration and location of each incidental capture.

Justification: As a protected species in Australia, all unintent ional catches of dolphins are required to be reported. The fishery has not previously reported catches although small numbers of bottlenose dolphins are known to be caught. They are usually dead when brought on deck.


113

The performance measure given above is intended to limit the dolphin catch of the fishery to the current level, which is considered to have a low impact on the local dolphin population. Results of the recent bycatch survey estimated that approximately 52 dolphins are caught by the fishery per year (Table 9). However, this may be an underestimate (P. Stephenson pers. comm.). The catch limit of 75 individuals is derived from the bycatch survey catch plus 50% to allow for a possible underestimation. The catch limit will be reviewed when additional data from new logbooks become available. Data Requirement for Indicator Data Required Availability Catch by trawl fishery

Voluntary trawl logbooks. To be completed by all skippers, recording each dolphin catch & associated shot details (trawl time, location). To be implemented in 2004.


Evaluation Summary: Population size estimates of dolphins in the region are not available, but are required to thoroughly evaluate the impact of the fishery on dolphins. Limited available data suggest that the level of impact by the fishery on dolphin populations is low. Additional monitoring of the fishery is required to provide a better estimate of the dolphin catch and to ensure that catches are minimised.

Fish trawl fisheries have operated in the Pilbara region since the 1960s. However, bottlenose dolphins are common in the Pilbara region, which suggests that the impact of trawling on the local dolphin population is relatively low. During the recent bycatch survey, 10-40 dolphins were observed in the vicinity of the trawl on most trips.

No other fishery in north-western Australia is known to catch dolphins. No other significant sources of dolphin mortality are known from the Pilbara region.

Robustness: Low The catch limit is based on a single estimate of annual catch (i.e. the recent bycatch survey). The bycatch survey was conducted over a 5-month period within a single year, and so did not provide an indication of seasonal or interannual variation in catches. The estimate of annual catch will remain uncertain until additional data from new logbooks become available. Catch data from new logbooks will then provide a moderately robust measure of performance. However, logbook data should to be validated by independent observers to reduce uncertainty.

The appropriateness of catch limits can only be fully evaluated when a regional estimate of dolphin population size becomes available.


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Fisheries Management Response Current: The fishery is managed through effort controls and gear restrictions. The value of an effort unit is reviewed annually and can be adjusted to change total or area-specific effort levels as required. Zone 1 and Areas 3 and 6 are closed to trawling.

Future: In 2004, the skipper’s logbook will be extended to collect additional data on the catch, release and mortality of protected species such as dolphins. Reporting of nil catches of protected species will also be required. It is recommended that an observer programme be developed to provide a regular assessment of bycatch by the fishery. Additional data from logbooks and observers will be used to review the appropriateness of performance measures, which are currently based on limited data.

It is proposed that a Code of Conduct be deve loped by industry to encourage the detailed reporting of all dolphin catches and promote fishing methods that are found to minimise dolphin capture. A Bycatch Action Plan is being developed for the fishery that will detail the management of dolphin bycatch.

Actions if Performance Limits are Exceeded: Unlike other captured species, dolphins are attracted to trawl vessels and deliberately enter nets. Therefore, management strategies that involve effort adjustment (e.g. closures) are not likely to be effective in reducing dolphin catches.

Acoustic 'pingers' have been used to reduce dolphin mortality in gillnet fisheries. An experimental study in the Bay of Fundy has shown a reduced bycatch of small cetaceans by 77% for nets with pingers (Trippel et al. 1999). These devices alert dolphins to the presence of the net and allow them to avoid it. However, this strategy is likely to be less successful in trawl fisheries because dolphins deliberately enter trawl nets. Acoustic 'pingers' have been used to deter dolphins from entering trawl nets (F. Koumas pers. comm.) but their effectiveness has yet to be established.

Escape grids in the cod ends of trawl nets are unlikely to reduce dolphin mortality in the fishery. In fact, the use of escape grids may be undesirable in regard to dolphin bycatch. Grids would not prevent dolphins from becoming entangled in the net and, if installed, may allow deceased dolphins to pass through the escape panel and cause their death to go unnoticed.

Anecdotal reports from fishers suggest that dolphin catches are greater in periods of rough weather or when fishing occurs during cross tides. Under these conditions, unpredictable net movements may cause dolphins to become disorientated in the net. For this reason, modifications to the mode of deployment/retrieval may be effective in reducing dolphin bycatch.

Demonstrating the success of any measure introduced in the fishery to reduce dolphin catches will be difficult due to the low level of the current catch.

Comments and Actions Dolphins are listed as protected species under the EPBC. It is an offence to kill, injure, take, trade, keep or move a member of a listed species without a permit.

Research to determine the size of local dolphin populations may be required to evaluate the appropriateness of performance measures.


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External Driver Check List Australia is obligated as a signatory of the Kyoto Agreement (Clucas 1997) to improve estimates of bycatch. Modifications to skipper’s logbooks will help to meet this obligation by encouraging trawl fishers to record interactions with protected species, including dolphins. Additional resources will be required to collate, analyse, disseminate and verify additional logbook data.

5.2.1.2 TURTLES Rationale for Inclusion: Turtles are known to be caught by the fishery.

ERA Risk Rating: Impact on breeding stock (C3 L3 MODERATE) The 2002 Bycatch Survey (Stephenson and Chidlow 2003) caught 6 green turtles (Chelonia mydas) and 1 loggerhead turtle (Caretta caretta) in 427 trawl shots. The loggerhead and 1 of the green turtles were dead when landed. The others were released alive. Anecdotal reports from fishers suggest that turtles are only occasionally caught by the fishery and are generally released alive. Data from the survey estimated that 91 turtles are caught by the fishery per year and, of these, approximately 72% are released alive (Table 9). The area of the fishery in which turtles are vulnerable to capture is small relative to the total range of each species. However, turtles grow and reproduce slowly and so even low levels of fishing mortality may be unsustainable. Therefore, it was considered that the fishery could have a 'severe' impact on breeding stocks of turtles, although this was 'unlikely'. This resulted in a risk rating of MODERATE.

Operational Objectives To maximise the accuracy of reporting of incidental captures. To minimise the incidental capture and mortality of turtles by the fishery.

Justification: Turtles are protected species and impacts resulting from the operations of the fishery should be managed. As a protected species, all incidental captures must be reported. Indicators 1) Number of turtles caught and their condition at release.

2) Level of compliance by skippers with the requirement to report all details of turtle captures.


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Performance Measures 1) Number of turtles caught should be reduced by 50% following implementation.

2) Number of turtles released alive should be greater than or equal to 72% of total captures per year.


Justification: As protected species in Australia, all unintentional catches of turtles are required to be reported. Catches have not previously reported by the fishery although small numbers of turtles are known to be caught. The above performance measures are intended to limit the turtle catch of the fishery to the current level, which is considered to have a low impact on turtle populations. Results of the recent bycatch survey suggested t hat 91 turtles are caught by the fishery per year, 72% of which are released alive. However, this is probably an overestimate of the catch (P. Stephenson pers. comm.). The bycatch survey was conducted in May/June. Turtle catches are likely to be seasonal a nd may be different at other times of year. For example, catches may be lower during summer when adult green and loggerhead turtles migrate inshore to breed. The breeding population size of female loggerhead turtles is estimated at approximately 10,000 (P reen et al, 1997). In 2000, an aerial survey in the Pilbara region estimated 50,000 green turtles in shallow (<20 m) water, with an unknown number in deeper water (Prince et al2000). Mortality rates in the fishery at or below levels suggested by the bycatc h survey would have a negligible impact on these populations. The above catch limit refers to the total turtle catch, regardless of species. Insufficient data is currently available to set catch limits for individual species. The catch limit will be revie wed and individual performance measures for each species will be developed when additional data from new logbooks become available.

Data Requirement for Indicator Data Required Availability Catch by trawl fishery

Voluntary trawl logbooks. To be completed by all skippers, recording each turtle catch & associated shot details (trawl time, location). To be implemented in 2004.



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Evaluation Summary: Limited available data suggest that the level of impact by the fishery on turtle populations is negligible. Additional monitoring of the fishery is required to provide better estimates of the catch and mortality of each turtle species and to ensure that mortality levels of each species are minimised.

Marine turtles have wide-ranging distributions and undertake lengthy migrations to breed. They mate and breed in coastal areas outside the boundaries of the trawl fishery. Also, most species of turtles (including green and leatherback turtles) typically feed in shallow areas, which are located inshore of the trawl grounds, and often forage in coral reefs, seagrass habitats or in the water column, where they are not exposed to trawling. These factors limit the opportunity for interaction between turtles and the fishery and therefore limit the potential impact of the fishery on turtle populations.

Results of the recent bycatch survey indicated that green and loggerhead turtles are caught by the fishery. It is possible that other species of turtles are also caught by the fishery on rare occasions, although no data is available about other species.

Other commercial fisheries: Turtles are caught by other trawl fisheries in northern Australia, although limited quantitative data about interactions with turtles is available from each fishery. Recent catch data from the Northern Prawn Fishery (NPF, in Commonwealth waters) and the Kimberley Prawn Managed Fishery (KMPF) suggest that the catch and mortality of turtles in these fisheries is at low levels and has declined in recent years after the implementation of turtle excluder devices (TEDs). The bycatch of turtles in the NPF and the KMPF is recorded in AFMA logbooks. In 2000, the number of individuals released alive and dead (in brackets) by the NPF was 12 (5) green, 19 (4) Pacific ridley, 9 (2) flatback, and 1 (1) hawksbill turtle. One turtle was caught by the KMPF in 2000.

Traditional Harvesting: Marine turtles have important cultural and social values for Aborigines and Torres Strait Islanders living in coastal areas of northern Australia. They are an essential food item for some of the island communities in the Torres Strait where there are few other sources of fresh red meat. Eggs of marine turtles are also an important source of protein. In a few communities, marine turtles are taken in large numbers for traditional feasting.

Green turtles are hunted more regularly than the other species. Hawksbill turtles are rarely hunted because they can be poisonous or unpleasant to eat. Most turtles are taken in the later part of the year, during the breeding season. To limit their impact on the stock, indigenous fishers usually take immature turtles in preference to adult-sized turtles, preferentially take eggs from nests that are likely to be washed by the tide and take male turtles in preference to female turtles during the breeding season.

Robustness: Low The catch limit is based on a single estimate of annual catch (i.e. the recent bycatch survey). The bycatch survey was conducted over a 5-month period within a single year, and so did not provide an indication of seasonal or interannual variation in catches. Turtles undertake summer migrations to inshore waters to breed and therefore their abundance in offshore waters (and likelihood of capture by the fishery) will also


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be seasonal. The estimates of annual catches of each turtle species will remain uncertain until additional data from new logbooks become available. Catch data from new logbooks will then provide a moderately robust measure of performance. However, logbook data should be validated by independent observers to reduce uncertainty.

Fisheries Management Response Current: The fishery is managed through effort controls and gear restrictions. The value of an effort unit is reviewed annually and can be adjusted to change total or area-specific effort levels as required. Zone 1 and Areas 3 and 6 are closed to trawling.

The Department of Fisheries requires that TEDs be installed in all prawn and scallop trawl fisheries operating in the Abrolhos Islands and northwards. A TED is a grid of bars, with an opening either at the top or the bottom, fitted into the neck of a trawl. Target species (fish, prawns) pass through the bars while large animals such as turtles and sharks are ejected through the openings. TEDs are intended to prevent accidental drownings of turtles in trawl nets. Marine turtles can spend up to half an hour underwater, before needing to surface to breath. TEDs have been demonstrated to reduce the rate of turtle capture in prawn trawl fisheries. TEDs have been mandatory in the NPF since 2000 and were introduced to the KMPF in 2002. Bycatch reduction devices were implemented in the Onslow, Broome and Nickol Bay Prawn Managed Fisheries during 2002/03.

Future: In 2004, the skippers logbook will be extended to collect additional data on the catch, release and mortality of protected species such as turtles. Reporting of nil catches of protected species will also be required. It is recommended that an observer programme be developed to provide a regular assessment of bycatch by the fishery. Additional data from logbooks and observers will be used to review the appropriateness of performance measures, which are currently based on limited data.

It is proposed that a Code of Conduct be developed by industry to encourage the detailed reporting of all turtle catches, communicate handling practises that maximise survivorship and promote fishing methods that are found to minimise turtle capture. A Bycatch Action Plan is being developed for the fishery that will detail the management of turtle bycatch.

Actions if Performance Limits are Exceeded: If the catch limit is exceeded, the management response may include an effort adjustment (e.g. time or area closure, area-specific effort reduction) to reduce fishing pressure in areas of high turtle abundance. Ability to implement these actions is provided through the FRMA and the Pilbara Fish Trawl Fishery Interim Management Plan 1997. The authority to adjust trawl effort is held by the Minister of Fisheries via authority to amend the Management Plan.

The introduction of TEDs or the limiting of trawl durations to <60 minutes may be effective in reducing turtle bycatch and mortality in fish trawl nets. However, demonstrating the success of any measure introduced in the fishery to reduce turtle catches would be difficult due to the low level of the current catch. Also, the use of TEDs in the PFTIMF is currently not desirable because they could prevent detection


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of dolphin mortality (dead dolphins could be ejected through escape panel and go undetected).

Comments and Actions The species Dermochelys coriacea (leatherback turtle) and all species in the family Cheloniidae are listed as protected species under the EPBC. It is an offence to kill, injure, take, trade, keep or move a member of a listed species without a permit (EPBC).

External Driver Check List Other threats to turtles include i) destruction of feeding grounds (e.g. seagrass beds), ii) degradation of breeding sites, iii) artificial lights (e.g. street or house lighting) near breeding beaches that disorientate hatchlings, iv) predation on hatchlings and eggs by foxes, pigs, goanna, v) direct hits by boats, and vi) ingestion of plastic bags (similar in appearance to jellyfish, a major prey item for some species).

Australia is obligated as a signatory of the Kyoto Agreement (Clucas 1997) to improve estimates of bycatch. Modifications to skipper’s logbooks will help to meet this obligation by encouraging trawl fishers to record interactions with protected species, including turtles. Additional resources will be required to collate, analyse, disseminate and verify additional logbook data.

5.2.1.3 SEASNAKES Rationale for Inclusion: Sea snakes are known to be caught by the fishery.

All species in the families Hydrophiidae and Laticaudidae are listed as protected species under the EPBC. It is an offence to kill, injure, take, trade, keep or move a member of a listed species without a permit (EPBC). Permits have not been issued to licensees in the PFTIMF.

ERA Risk Rating: Impact on breeding stock (C1 L6 LOW) Sea snakes are occasionally caught by the fishery and the majority are released alive. The 2002 Bycatch Survey (Stephenson and Chidlow 2003) caught 21 sea snakes, which were probably Hydrophis elegans, in 427 trawl shots. All individuals were released alive. Data from the survey suggest that approximately 270 sea snakes are caught and released alive by the fishery per year (Table 9).

At the risk rating workshop in December 2002, it was considered 'possible' that the fishery could have a 'severe' impact on the stocks of sea snakes. However, lack of background information about sea snakes at the meeting was noted as a difficulty in rating this issue. Better documentation was requested. A subsequent review of available literature (see below and Background section) suggested that the fishery was


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'likely' to have a 'minor' impact on breeding populations of sea snakes. This resulted in a risk rating of LOW.

No estimates of population size are available for local sea snakes but many species are commonly observed in the Pilbara region and none are listed as vulnerable. Apart from the impact of fish and prawn trawling, there are probably few other threats to sea snake populations. The likelihood of survival is high for sea snakes that are released after capture by trawling. A study in the Gulf of Carpentaria found that 60% of sea snakes survive capture by prawn trawling (Wassenburg et al. 1994). Stobutzki et al. (2000) reported that in commercial prawn trawl shots of duration >180 min, the mortality of sea snakes ranged from 20-59%. Sea snakes are usually quite active when brought on deck, suggesting that they suffer limited harm during capture.

Sea snakes are potentially vulnerable to overfishing because they grow and reproduce slowly. However, the impact of the fishery on sea snake populations is likely to be minor because the area of the fishery in which sea snakes are vulnerable to capture is small relative to the total distribution of each species. The distribution of Hydrophis elegans includes shallow waters inshore of the fishery, and closed areas within the fishery (Zone 1 and Area 3) where they are not subject to fishing pressure. Also, sea snakes are not vulnerable to demersal trawling while swimming at the surface or in the water column.

Hydrophis elegans occurs across northern Australia and New Guinea (Heatwole 1999). It is one of the most common species of sea snakes caught by fish and prawn trawl fisheries in northern Australia. Ward (1996) observed that H. elegans commonly escape through trawl meshes because of their slender shape. During the recent bycatch survey, catch rates of Hydrophis elegans were highest in depths of 50-70 m. Sea snake catch rates are probably always low in the deeper areas (>75 m) of the fishery because sea snakes are relatively rare in offshore waters.

Action: Although the impact on sea snake stocks by the fishery is probably minimal, the performance of the fishery in regard to bycatch of sea snakes could be improved. Additional monitoring of the fishery is required to ensure catches of sea snakes remain at a low level. Also, as a protected species in Australia, all unintentional catches by the fishery are required to be reported.

Sea snake catches have not previously been reported by the fishery, although they are known to be caught. In 2004, the skipper’s logbook will be extended to collect additional data on the catch, release and mortality of protected species such as sea snakes. Reporting of nil catches of protected species will be also required. It is recommended that an observer programme be developed to provide a regular assessment of bycatch by the fishery.

It is proposed that a Code of Conduct be developed by industry to encourage the detailed reporting of sea snake catches and promote handling practises that minimise sea snake mortality. A Bycatch Action Plan is being developed for the fishery that will detail the management of sea snake bycatch.


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5.2.1.4 SYNGNATHIDS Rationale for Inclusion: Syngnathids are known to be caught by the fishery.

ERA Risk Rating: Impact on breeding stock (C2 L6 MODERATE) The 2002 Bycatch Survey (Stephenson and Chidlow 2003) caught 34 pallid pipefish (Solegnathus hardwickii) and 4 spiny seahorses (Hippocampus histrix) in 427 trawl shots. Most individuals were dead when landed. Data from the survey suggest that approximately 450 pipefish and 50 seahorses are caught by the fishery per year (Table 9).

The area of the fishery in which syngnathids are vulnerable to capture is small relative to the total distribution of each species. However, syngnathids are vulnerable to overfishing because they reproduce relatively slowly, have low rates of dispersal and are highly habitat dependent. Also, the distribution and biology of many syngnathids is poorly understood. Although the fishery probably exerts a minimal impact on syngnathid populations, it was considered that this impact was at the maximum acceptable level (level 2) in most circumstances (level 6), given the protected status of these species. This resulted in a risk rating of MODERATE.

Operational Objectives To limit the incidental mortality of syngnathids in the fishery. To maximise the accuracy of reporting of incidental captures.

Justification: Syngnathids are protected species and impacts resulting from the oper ations of the fishery should be managed. As protected species, all incidental captures must be reported. Indicators 1) Number of syngnathids caught.

2) Level of compliance by skippers with the requirement to report all details of syngnathid captures.

Performance Measures 1) Number of pipefish caught and released alive should be less than 500 per year.

2) Number of seahorses caught and released alive should be less than 60 per year.



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Justification: As protected species in Australia, all unintentional catches of syngnathids are required to be reported. The fishery has not previously reported catches although small numbers of syngnathids are known to be caught. The above performance measures are intended to limit pipefish and seahorse catches by the fishery to the current levels, which are considered to have a low impact on populations of each species. The recent bycatch survey of the fishery sugg ested that 450 pallid pipefish and 50 spiny seahorses are caught by the fishery per year. Population size estimates are not available for syngnathid species. However, both species caught in the survey have very broad distributions, relative to the area of the fishery, and so the current level of impact by the fishery, as suggested by the results of the bycatch survey, on total population size or dynamics is likely to be negligible. The above catch limits refers to the total pipefish and total seahorse catc hes, regardless of species. Insufficient data is currently available to set catch limits for individual species. The catch limit will be reviewed and individual performance measures for each species will be considered when additional data from new logbooks become available. However, it may not be feasible for fishers to identify syngnathids to species level. Also, the additional resources that would probably be required to identify syngnathids to species level would not be warranted at the currently low lev el of impact. Data Requirement for Indicator Data Required Availability Catch by trawl fishery

Voluntary trawl logbooks. To be completed by all skippers, recording syngnathid catches & associated shot details (trawl time, location). To be implemented in 2004.



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Evaluation Summary: Limited available data suggest that the level of impact by the fishery on syngnathid populations is negligible. Additional monitoring of the fishery is required to provide better estimates of the catches of pipefish and seahorses and to ensure that the impact by the fishery on syngnathids remains low.

The area of the fishery in which syngnathids are exposed to trawling is small relative to the total dis tribution of each species. Both pallid pipefish and spiny seahorses occur throughout the Indo-West Pacific. Their distributions include shallow shelf waters inshore of the fishery and closed areas within the fishery (Zone 1 and Areas 3 and 6). Syngnathids are typically associated with structurally complex habitats such as reefs, sponges and seagrass, where they are not exposed to trawling. During the recent bycatch survey, catch rates of pallid pipefish were highest at 80-100 m, suggesting that this species may be abundant in the shallow portion of Area 6. Area 6, which is closed to trawling, may therefore be a source of recruitment to adjacent areas.

Results of the recent bycatch survey indicated that pallid pipefish and spiny seahorses are caught by the fishery. It is possible that other species of syngnathids are also occasionally caught, although no data is available.

Syngnathids are known to be caught by prawn trawl fisheries in WA. However, the species composition and quantity of the catch is unknown. Prawn trawling occurs in shallower water than fish trawling, and so different species may be caught. Preliminary surveys of bycatch in the Onslow and Nickol Bay prawn trawl fisheries have begun with two trips carried out before mid-2004, which will provide data about syngnathid catches by these fisheries.

Aquarium trade: Syngnathids in WA are legally retained by licensees in the Marine Aquarium Fish Managed Fishery. This fishery operates statewide and has a total catch limit of 750 syngnathids per year. The catch limit for this fishery is determined by DEH. In 2001, 325 seadragons, 386 seahorses and 30 pipefish were caught. However, the Marine Aquarium Fish Managed Fishery targets shallow water species and therefore probably impacts on different syngnathid populations to those impacted by trawling.

Robustness: Low The catch limits are based on a single estimate of annual catches (i.e. the recent bycatch survey). The bycatch survey was conducted over a 5-month period within a single year, and so did not provide an indication of seasonal or interannual variation in catches.

The estimates of annual catches will remain uncertain until additional data from new logbooks become available. Catch data from new logbooks will then provide a moderately robust measure of performance. However, logbook data should be validated by independent observers to reduce uncertainty.

It may be difficult to determine species-specific catch rates from logbooks, because it may be difficult for fishers to identify syngnathids to a species level. Assistance to skippers with identification, or an alternative source of data (such as the observer programme) may be required to collect catch data at a species level.


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Fisheries Management Response Current: The fishery is managed through effort controls and gear restrictions. The value of an effort unit is reviewed annually and can be adjusted to change total or area-specific effort levels as required. Zone 1 and Areas 3 and 6 are closed to trawling. Closed areas provide refugia for syngnathids within the fishery.

Future: In 2004, the skipper’s logbook will be extended to collect additional data on the catch, release and mortality of protected species such as syngnathids. Reporting of nil catches of protected species will be also required. It is recommended that an observer programme be developed to provide a regular assessment of bycatch by the fishery. Additional data from logbooks and observers will be used to review the appropriateness of performance measures, which are currently based on limited data.

It is proposed that a Code of Conduct be developed by industry to encourage the reporting of all syngnathid catches. A Bycatch Action Plan is being developed for the fishery that will detail the management of syngnathid bycatch.

Actions if Performance Limits are Exceeded: The performance measures for syngnathids are based on very limited data and annual catch levels of these species are likely to be highly variable. Hence, it is likely that performance limits will be exceeded in some years. If the catch limit is exceeded, the initial management response will be a review of available fishery and biological data. In particular, additional data from logbooks and observers will allow the appropriateness of performance limits to be re-assessed.

If the catch limit is exceeded and available data suggest that the fishery is having a significant impact on a syngnathid population, the management response may include an effort adjustment (e.g. time or area closure, area-specific effort reduction) to reduce fishing pressure in areas of high syngnathid abundance. Ability to implement these actions is provided through the FRMA and the Pilbara Fish Trawl Fishery Interim Management Plan 1997. The authority to adjust trawl effort is held by the Minister of Fisheries via authority to amend the Management Plan.

Comments and Actions All species in the family Syngnathidae are listed as protected species under the EPBC. It is an offence to kill, injure, take, trade, keep or move a member of a listed species without a permit (EPBC). Permits have not been issued to licensees in the PFTIMF.

Pipefish caught by the fishery are often retained. They are dried and sold on Asia markets. Trawl fishers are not licenced to retain syngnathids and yet this practice occurs. Regulations regarding syngnathid collection by trawl fishers need to be clarified. The practise of retaining pipefish may be difficult to eliminate in the fishery, given that pipefish are often dead when landed and can be sold at high prices. In the future, if trawl fishers are endorsed to retain syngnathids as byproduct, then catches will be reported on the monthly Marine Aquarium Fish Managed Fishery returns.

The impact of syngnathid collecting, including pipefish taken by the PFTIMF, will be considered in the ecological assessment of the Marine Aquarium Fish Managed Fishery.


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External Driver Check List General threats to syngnathids include i) destruction of habitat (e.g. seagrass beds) and ii) illegal harvesting for the aquarium trade or for traditional medicines.

Pipefish of the genus Solegnathus are the most valuable syngnathids in traditional Chinese medicine. Pallid pipefish are listed as vulnerable on the 2002 IUCN Red List. However, there is no evidence of population decline in this species (Pogonowski et al. 2002). The use of spiny seahorses in traditional Chinese medicine is limited but increasing (Lourie et al. 1999). Spiny seahorses are not common in the aquarium trade.

Australia is obligated as a signatory of the Kyoto Agreement (Clucas 1997) to improve estimates of bycatch. Modifications to skippers logbooks will help to meet this obligation by encouraging trawl fishers to record interactions with protected species, including syngnathids. Additional resources will be required to collate, analyse, disseminate and verify additional logbook data.

5.2.1.5 SAWFISH Rationale for Inclusion: Sawfish are known to be caught by the fishery.

ERA Risk Rating: Impact on breeding stock (C2 L6 MODERATE) The 2002 Bycatch Survey (Stephenson and Chidlow 2003) caught 2 green sawfish (Pristis zijsron) and 6 narrow sawfish (Anoxypristis cuspidata) in 427 trawl shots. Sawfish are generally killed by fishers to avoid personal injury when removing them from the net. Data from the survey suggest that approximately 25 green sawfish and 80 narrow sawfish are caught by the fishery per year (Table 9).

The area of the fishery in which green and narrow sawfish are vulnerable to capture is small relative to the total range of each species, suggesting that the fishery has limited impact on each population. However, sawfish grow and reproduce slowly and so even low levels of fishing mortality may be unsustainable. The global population of narrow sawfish has been estimated to be < 50% of virgin levels (Pogonoski et al. 2002). The status of green and narrow sawfish populations in north-western Australian is unclear but each species is believed to be relatively abundant, compared with other regions (R. McAuley pers. comm.). The limited information that is available about the life history of sawfish in Australian waters contributes to uncertainty about stock status. Although the fishery probably exerts a minimal impact on the stocks of sawfish, it was considered that this impact was at the maximum acceptable level (level 2) in most circumstances (level 6), given the vulnerability of these species. This resulted in a risk rating of MODERATE.


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Operational Objectives To minimise the incidental mortality of sawfish in the fishery. To maximise the accuracy of reporting of incidental captures.

Justification: Sawfish are vulnerable to overfishing and impacts resulting from the operations of the fishery should be managed. Narrow and green sawfish are each listed as endangered on the World Conservation Union (IUCN) Red List of Threatened Species.

Indicators 1) Number of sawfish caught and their condition at release.

2) Level of compliance by skippers with the requirement to report all details of sawfish captures.

Performance Measures 1) Number of sawfish caught should be less than 120 per year.

2) Number of sawfish released alive should be increased to 50% of captures by 2008.


Justification: The above performance measures are intended to li mit sawfish catches by the fishery to the current levels, which are considered to have a low impact on populations of each species. The recent bycatch survey of the fishery suggested that approximately 25 green sawfish and 80 narrow sawfish are caught by the fishery per year. Population size estimates of sawfish are not available. However, all sawfish species that are vulnerable to capture by the fishery have broad distributions relative to the area of the fishery, and so the current level of impact by the fishery, as suggested by the results of the bycatch survey, on total population sizes or dynamics is likely to be low. The above catch limit refers to the total sawfish catch, regardless of species. Insufficient data is currently available to set catch l imits for individual species. The catch limit will be reviewed and individual performance measures for each species will be considered when additional data from new logbooks become available.


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The development of handling practises that allow a greater prop ortion of sawfish to be released alive is desirable, given the vulnerability of sawfish to overfishing. Data Requirement for Indicator Data Required Availability Catch by trawl fishery

Voluntary trawl logbooks. To be completed by all skippers, recording all sawfish catches & associated shot details (trawl time, location). To be implemented in 2004.


Evaluation Summary: Limited available data suggest that the level of impact by the fishery on sawfish populations is low. Additional monitoring of the fishery is required to provide a better estimate of catches of each species and ensure catch levels of each species are minimised. New handling practises need to be developed to reduce mortality of sawfish.

The limit of the distribution of green and narrow sawfish species is generally considered to be the Kimberley region. Therefore, sawfish catches in the Pilbara region are expected to be relatively low because the Pilbara region is at the extremity of their distribution.

Green and narrow sawfish have wide-ranging tropical distributions across northern Australia and are capable of long distance movements. They occur in coastal, estuarine or freshwater areas. Locally they may occur in open and closed areas of the fishery, and in waters inshore of the boundary of the fishery. Therefore, the total area of the fishery in which sawfish are exposed to trawling is small relative to the total range of each species.

It is possible, but unlikely, that dwarf sawfish (Pristis clavata) and freshwater sawfish (Pristis microdon) are also occasionally caught by the fishery. There are no recorded catches of these species. Dwarf and freshwater sawfish mainly occur in coastal, estuarine or fresh waters. Also, the Pilbara region is believed to be at the western extremity of the distribution of dwarf sawfish.

In general, sawfish are caught by various commercial fisheries in the marine and estuarine waters of northern Australia, including prawn trawling, fish trawling and gill netting (Pogonowski et al. 2002). Sawfishes are probably also occasionally taken by recreational fishers in the region. No estimates of the overall catch of sawfish are available.

Several factors make sawfish vulnerable to overfishing, including slow rates of growth and reproduction. Also, their coastal distributions increase their likelihood of exposure to various types of fishing and other anthropogenic pressures, and their morphology increases their susceptibility to net entanglement. Fishers generally kill them to avoid personal injury when removing them from the net (R. McAuley pers. comm.). For this reason, few sawfish are released alive by the fishery despite the fact that they are not retained for sale.


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Robustness: Low The catch limits are based on a single estimate of annual catches (i.e. the recent bycatch survey). The bycatch survey was conducted over a 5-month period within a single year, and so did not provide an indication of seasonal or interannual variation in catches.

The estimates of annual catches will remain uncertain until additional data from new logbooks become available. Catch data from new logbooks will then provide a moderately robust measure of performance. However, logbook data should be validated by independent observers to reduce uncertainty.

Fisheries Management Response Current: The fishery is managed through effort controls and gear restrictions. The value of an effort unit is reviewed annually and can be adjusted to change total or area-specific effort levels as required. Zone 1 and Areas 3 and 6 are closed to trawling. Closed areas provide refugia for sawfish within the fishery.

Future: In 2004, the skipper’s logbook will be extended to collect additional data on the catch, release and mortality of sawfish. It is recommended that an observer programme be developed to provide a regular assessment of bycatch by the fishery. Additional data from logbooks and observers will be used to review the appropriateness of performance measures, which are currently based on limited data.

It is proposed that a Code of Conduct be developed by industry to encourage the detailed reporting of all sawfish catches and promote handling practises that minimise sawfish mortality. For example, bending of the dorsal fin can temporarily put sawfish "to sleep" and allow them to be safely removed from the net (R. McAuley pers. comm.). A Bycatch Action Plan is being developed for the fishery that will detail the management of sawfish bycatch.

Actions if Performance Limits are Exceeded: The performance measures for sawfish are based on very limited data and annual catch levels of these species are likely to be variable. Hence, it is likely that performance limits will be exceeded in some years. If the catch limit is exceeded, the initial management response will be a review of available fishery and biological data. In particular, additional data from logbooks and observers will allow the appropriateness of performance limits to be re-assessed.

If the catch limit is exceeded and available data suggest that the fishery is having a significant impact on a sawfish population, the management response may include an effort adjustment (e.g. time or area closure, area-specific effort reduction) to reduce fishing pressure in areas of high sawfish abundance. The ability to implement these actions is provided through the FRMA and the Pilbara Fish Trawl Fishery Interim Management Plan 1997. The authority to adjust trawl effort is held by the Minister of Fisheries via authority to amend the Management Plan.


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Comments and Actions The global population of narrow sawfish has been estimated to be < 50% of virgin levels (Pogonoski et al. 2002). Narrow, green and dwarf sawfish are each listed as endangered on the World Conservation Union (IUCN) Red List of Threatened Species. Green sawfish is currently under nomination for listing as endangered under the EPBC Act.

External Driver Check List Sawfish are harvested illegally for use as traditional medicines or as souvenirs. Sawfish fins fetch high prices on Asian markets. Sawfish populations are also threatened by degradation of inshore habitats.

Australia is obligated as a signatory of the Kyoto Agreement (Clucas 1997) to improve estimates of bycatch. Modifications to skipper’s logbooks will help to meet this obligation by encouraging trawl fishers to record interactions with protected species, including sawfish. Additional resources will be required to collate, analyse, disseminate and verify additional logbook data.

5.2.2 OTHER SPECIES 5.2.2.1 MORAY EELS Rationale for Inclusion: Moray eels are known to be caught by the fishery.

ERA Risk Rating: Impact on breeding stock (C1 L6 LOW) Moray eels are occasionally caught by the fishery and the majority are released alive. They tend to occur in the catch attached to pieces of coral or sponge. The 2002 Bycatch Survey (Stephenson and Chidlow 2003) caught 192 moray eels, which were probably Gymnothorax undulatus, in 427 trawl shots. Data from the survey suggest that approximately 2500 moray eel are caught and released alive by the fishery per year. Moray eels are not known to be caught in significant quantities by any other fishery in the region.

The area of the fishery in which moray eels are vulnerable to capture is small relative to the total range of each species. Gymnothorax undulates is probably the main species caught by the fishery and this species is common throughout the Indo-west Pacific region. The distribution of this species includes shallow shelf waters inshore of the fishery and closed areas within the fishery (Zone 1 and Areas 3 and 6). Moray eels are typically associated with structurally complex habitats such as reefs and sponges, where they are not exposed to trawling.

Therefore, it was considered that the fishery was 'likely' to have a 'minor' impact on breeding populations of moray eels. This resulted in a risk rating of LOW.


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5.2.2.2 UNMARKETABLE SCALEFISH Rationale for Inclusion: Numerous species of scalefish are caught and discarded by the fishery, generally because they are unmarketable.

ERA Risk Rating: Impact on breeding stock (C1 L6 LOW) Results of the 2002 Bycatch Survey (Stephenson and Chidlow 2003) suggested that approximately 1000 t of scalefish are discarded by the fishery per year. The total number of scalefish species caught and discarded by the fishery is unknown, but may exceed 100. Many discarded species are rare in catches and so annual catches of each species are very small.

The bycatch survey identified 31 taxa that comprise the bulk of scalefish discards by the fishery. These taxa are listed in Table 17. Some of these species are caught in significant quantities only by the PFTIMF and many are discarded when caught by any fishery because they are of little or no commercial value.

Discards of individual species of scalefish occur in minor quantities, relative to the likely stock size of each species. Also, the area of the fishery in which each species is vulnerable to capture is small compared to the total distribution of each species. None of the species that comprise the bulk of the discarded scalefish catch have life history characteristics that make them vulnerable to overfishing (Stephenson and Chidlow 2003).

Therefore, it was considered that the fishery was 'likely' to have a 'minor' impact on breeding populations of discarded scalefish. This resulted in a risk rating of LOW.

Lizardfish (mainly Saurida undosquamis) are the most common taxa in the discarded component of the catch. Lizardfish occur over soft sediments, which are favoured by trawlers. Results of the recent bycatch survey suggest that approximately 280 t of lizardfish are caught and discarded by the fishery per year. Lizardfish are also discarded by state and Commonwealth prawn trawl fisheries in northern and western Australia (e.g. Blaber et al. 1994). The lizardfish bycatch of the Northern Prawn Trawl Fishery has been estimated at 3650 t per year (Kailola et al. 1993). Prior to 1989, up to 1200 t of lizardfish were retained by Thai and Taiwanese demersal fish trawlers from the NW Shelf, Timor and Arafura Seas. There is a market for dried S. undosquamis in Taiwan (Kailola et al. 1993). Lizardfish are moderately resilient to overfishing because they are relatively short- lived and reproduce relatively quickly. No population size estimates are available for lizardfish, but populations across northern Australia are likely to have increased in size as a result of seabed modification by trawling (Sainsbury 1987).

Triggerfish (mainly Abalistes stellaris) are the second most common taxa in the discarded component of the catch. Results of the recent bycatch survey suggest that approximately 160 t of triggerfish are caught and discarded by the fishery per year. Small quantities of triggerfish are also discarded by prawn trawl and trap fisheries in north-western Australia (e.g. Blaber et al. 1994, Newman et al. 2001). There are no markets for triggerfish.


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Table 17 Main species of scalefish discarded by the PFTIMF and annual

discarded catch, as estimated from bycatch survey. The total WA catch (i.e. amount retained by all WA commercial fisheries) is also shown.

No population size estimates are available for triggerfish. However, the impact of the fishery on Abalistes stellaris is likely to be small because the area of the fishery in which it is vulnerable to trawling is small relative to the total distribution of this species. A. stellaris has a wide species distribution throughout the Indo-west Pacific. It occurs across a wide range of depths and habitat types in northern Australian waters, including coastal waters inshore of the trawl fishery (Blaber et al. 1994). In general, triggerfish are often associated with reef habitats, which are avoided by trawlers. Closed Areas (Zone 1 and Areas 1 and 3) provide additional refugia for triggerfish within the fishery.

Numerous species of scalefish are caught and discarded by the fishery because they are unsaleable, unpalatable or poisonous. Some scalefish may be discarded if freezer/storage space is unavailable at the time of capture. The value of the fishery could be increased if markets could be developed for species that are currently unsaleable. This would reduce wastage of discarded fish, which a have a low probability of survival.

Common name Scientific name(s)PFTF annual

discards (t)

WA total reported catch (t) 2000/01

Commercial value?

Catch/bycatch by fisheries other than PFTF?

Comment

Checkered lizardfish Saurida undosquamis 277 - no Prawn trawlTriggerfish Abalistes stellaris 159 - no Pilbara & Kimberley trap catches are mostly

Pseudobalistes fuscus A. stellatusSufflamen fraenatus

Trevally Caranx spp. 60 213 yes some species are retainedCarangoides spp.

Threadfin bream Nemipterus fucosus 57 220 yes discards are small fishLunar-tailed bigeye Priacanthus spp. 44 31 limited catch is mostly P. hamrurJavelinfish Pomadasys kaakan 33 31 limited Prawn trawl (P. maculatum ) catch is mainly P. kaakan

P. maculatum P. maculatum is discardedCatfish Arius spp. 32 42 limitedToadfish Lagocephalus spp. 29 - no

L. sceratusSquirrelfish Holocentridae 26 - noFive-lined flagfish Lutjanus quinquelineatus 20 - limited also reported as "flagfish"Seapike Sphyraena spp. 6 4 limitedRed emperor Lutjanus sebae 5 235 yes Pilbara & Kimberley trap discards are small fishAlbacore Thunnus alalunga 4 - yes also reported as "tuna".Blacktip tripodfish Trixiphichthys weberi 4 - noBatfish Platax batavianu 3 - no

Zabidius novemaculeatusFlutemouth Fistularia commersonii 2 - no Prawn trawl

F. petimbaFalse flagfish Lutjanus lutjanus 1 - no also reported as "flagfish"Fortesque Apolectus niger 1 - no Prawn trawlBlue-spot emperor Lethrinus hutchinsi 1 229 yes Pilbara & Kimberley trapBonito Cybiosarda elegans 0.5 - noBarracuda Sphyraena barracuda 0.3 1.5 noMottled moray eel Gymnothorax undulatus 0.1 - noStriped catfish Plotosus lineatus 0.1 - noFrigate mackerel Auxis thazard 0.1 - noFlagfish Lutjanus vitta 0.1 192 yes Pilbara & Kimberley trap catch includes other lutjanidsOther scalefish 260Total 1025


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5.2.2.3 ELASMOBRANCHS Rationale for Inclusion: Twenty four species of sharks and 10 species of rays are known to be caught by the PFTIMF. Approximately 60 % (by weight) of the shark catch is discarded. The majority of rays are discarded. ERA Risk Rating: Impact on breeding stock (C1 L6 LOW) Results of the 2002 bycatch survey (Stephenson and Chidlow 2003) suggested that approximately 150 t of sharks are discarded by the fishery per year.

While the total discarded catch of elasmobranchs by the fishery is significant, the discarded catch of each species is small. Most elasmobranch species discarded by the fishery are also discarded by other fisheries. Larger sharks have a higher probability of survival after release than smaller sharks. The area of the fishery in which elasmobranchs are vulnerable to trawling is small relative to the total distribution of each species. Therefore, it was considered that the fishery was 'likely' to have a 'minor' impact on breeding populations of discarded elasmobranchs. This resulted in a risk rating of LOW.

Elasmobranchs that are most vulnerable to overfishing are those species, such as sandbar shark, that have i) a highly K-selected life history (long- lived, slow to reproduce), and ii) high commercial value and are therefore retained by this fishery and other fisheries. The management of such vulnerable species is discussed within this report under Section 5.1.2.1, and discussed in detail in the ecological assessments of the JASDGDLF) and the WCDGDDF and the ecological assessments of the NCSF.

The quantity and type of sharks that are discarded by the fish trawl fishery varies considerably among vessels. Between 0 and 80% of sharks caught may be retained, depending on the vessel. The decision to retain or discard a shark is affected by marketability and vessel storage capacity. Of the marketable species, generally only large (i.e. length >100 cm) individuals are retained because of their higher value, and smaller individuals of the same species are discarded. Hence, the majority of the catch (by weight) of "marketable" species may still be discarded.

Some elasmobranch species are almost always discarded. These include weasel, sliteye, milk, Australian sharpnose, golden-eye shovelnosed ray, leopard, sharkray, tassled wobbegong, northern wobbegong, grey carpet, banded catshark and tawny nurse sharks (Table 18). A further 7 species of rays are always discarded (Table 19). Some sharks, especially larger individuals, and all rays that are discarded have a high probability of survival after release (R. McAuley pers. comm.).

Results of the bycatch survey suggested that leopard sharks and whitespot guitarfish are the greatest contributors by weight to annual shark discards (approximately 51 t and 38 t, respectively). The fishery generally catches large leopard sharks, which are of low value, and these have a high probability of survival after release. Most whitespot guitarfish caught by the fishery are small. They are of low value and are discarded. Large guitarfish are of higher value and are generally retained. Small guitarfish have a low probability of survival after release (P. Stephenson pers. comm.).


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The individual catch of each elasmobranch species that is discarded by the fishery is low. Discards of each shark species, other than leopard sharks and whitespot guitarfish, are estimated to be between 0 and 12 t per year (Table 18).

Approximately 2000 rays, comprising various species, were caught during the bycatch survey (Table 19). Catches of rays were not weighed during the survey, so quantitative estimates of catch per species are not available.

Table 18 Annual catches of main species of discarded elasmobranchs caught by

the PFTIMF, estimated from results of 2002 bycatch survey.

Data from 2002 Bycatch Survey

Common name Scientific name Individuals% retained (by number)

Weight (kg)

% retained (by weight)

Estimated annual catch (t)

Mostly discarded by fishery?

Leopard/zebra Stegastoma fasciatum 101 0 3909 0 51 yesWhite-spot guitarfish Rhynchobatus djiddensis 251 8 2913 36 38 yes, if smallSandbar Carcharhinus plumbeus 89 48* 2523 52* 33 -Pigeye Carcharhinus amboinensis 3 100 1670 100 22 -Tiger Galeocerdo cuvier 5 40 1539 23 20 yesWeasel Hemigaleus microstoma 559 3 987 4 13 yesGreat hammerhead Sphyrna mokarran 7 86 963 90 13 -Blacktip Carcharhinus tilstoni/limbatus 79 43 951 68 12 -Shovelnose rays Rhinobatos spp. 356 3 822 38 11 yesMilk Rhizoprionodon acutus 238 8 548 9 7 yesFossil Hemipristis elongata 27 67 246 72 3 -Whitecheek Carcharhinus dussumieri 102 7 238 9 3 yesTawny nurse Nebrius ferrugineus 4 0 203 0 3 yesSharpnose Rhizoprionodon taylori 114 8 184 10 2 yesScalloped hammerhead Sphyna lewini 115 0 183 0 2 yes, if smallSpot tail Carcharhinus sorrah 25 0 84 0 1 yesSmooth hammerhead Sphyrna zygaena 1 0 65 0 0.8 -Sharkray Rhina ancylostoma 4 0 43 0 0.6 yes, if smallGrey carpet Chiloscyllium punctatum 12 0 26 0 0.3 yesTasselled wobbegong Eucrossorhinus dasypogon 4 0 22 0 0.3 yesBanded catshark Atelomycterus sp. A 42 0 15 0 0.2 yesWinghead Eusphyra blochii 1 0 13 0 0.2 yesBignose Carcharhinus altimus 6 0 8 0 0.1 yesSpinner Carcharhinus brevipinna 1 0 4 0 0.1 yes, if smallNorthern wobbegong Orectolobus wardi 2 0 10 0 0.1 yesSliteye Loxodon macrorhinus 1 0 2 0 < 0.1 yes, if small

All elasmobranchs 236

(*some individuals tagged & released during survey, but these would normally be retained)


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Table 19 Species of rays caught and discarded during the 2002 bycatch survey,

and estimated annual fishery catch.

Ray catch during survey comprised 1777 small, 118 medium and 118 large sized individuals. (No catch weight data available for ray species). 5.2.2.4 MACRO-INVERTEBRATES Rationale for Inclusion: Small quantities of tropical lobsters, deepwater crabs, echinoderms and benthic octopus are caught and discarded by the fishery.

ERA Risk Rating: Impact on breeding stocks (C1 L4 LOW) The catch of each macroinvertebrate species is low and none is retained as byproduct by the fishery. Discarded molluscs and crustaceans have a high probability of survival. The area of the fishery in which each species is vulnerable to capture by trawling is small relative to the total distribution of the species. Each species is relatively short- lived and moderately fecund, and so is likely to be resilient to low levels of fishing pressure exerted by the trawl fishery. Also, a pelagic larval phase allows each species to disperse widely and would facilitate annual recruitment to each area of the fishery. Therefore, it was considered 'possible' that the fishery exerts a 'minor' impact on the population of each macroinvertebrate species. This resulted in a risk rating of LOW.

Ornate lobster. Results of the 2002 Bycatch Survey (Stephenson and Chidlow 2002) suggest that approximately 1000 ornate lobsters (Palinurus ornatus) are caught by the fishery per year. Ornate lobsters were caught at all depths of the survey (i.e. 50 to 100 m) but catches were largely restricted to Area 1. In WA, lobsters are not permitted to be caught by trawling, and must be released. They have a high probability of survival after release (R. Melville-Smith pers. comm.). There is likely to be some unreported collection of lobsters by trawl fishers for personal consumption. Also, recreational fishers in the region may catch and retain small numbers of ornate lobsters. Ornate lobsters are commercially fished in Qld and the Torres Strait. However, there is no commercial catch of ornate lobster in WA.

Ray species Common name Size group

Aetobatus narinari white-spotted eagle ray largeTaeniura meyeni blotched fantail ray largeHimantura uarnak reticulate whipray largeHimantura sp. brown whipray medium/largeDasyatis kuhlii blue-spotted maskray small/mediumDasyatis spp. n/a small /mediumGymnura australis Australian butterfly ray small


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Ornate lobster are widely distributed throughout the Indo-west Pacific. They occur at depths of 0 to 200 m in a range of habitat types, including sponges, rubble, coral and rocky reefs (Kailola et al. 1993). Adults undertake lengthy spawning migrations, at which times they can form dense aggregations. This aggregating behaviour may make them more vulnerable to capture by trawling during the cooler months of the year. A pelagic larval phase of 4-10 months allows the species to disperse widely.

Red spear lobster. (Linuparus trigonus) is distributed across northern Australia and south-east Asia. It is of limited commercial significance throughout its range. It is a deepwater species, occurring at depths of 81-313 m over sand or mud bottoms (Wadley and Evans 1991). Red spear lobster was previously caught in Area 6, prior to that area being closed to trawling, but is now rarely caught by the fishery. The fishery is expected to have negligible impact on this species while Area 6 remains closed.

Crabs. Crabs are occasionally caught by the fishery but are not retained as byproduct. They have a high probability of survival after release. At least 2 species of crabs (Decapoda) were caught in low numbers in the bycatch survey (J. Chidlow pers. comm.). These crabs were not formally identified but, based on external appearance, were probably coral crabs (Charybdis spp.) and spider crabs (family Majidae). Spider crabs have no commercial value and are not retained by any fishery in the region. Coral crabs have limited value and are retained in small quantities by the blue swimmer crab fishery, which is based in Port Headland (L. Bellchambers pers. comm.).

Octopus. Results of the bycatch survey suggest that approximately 520 individual octopus (Octopodidae) are caught by the fishery per year. Individuals caught during the survey were not identified, but may have been one of several deepwater, benthic species that occur in the region. Octopus were caught at all depths of the survey (i.e. 50 to 100 m), but catches were mostly restricted to Area 1. Octopus are not currently retained by the fishery, although small quantities have been retained in previous years. The last reported catch of octopus by the trawl fishery was in 1996, when 763 kg were reported.

In Western Australia, a commercial catch of 104 t of octopus was reported in 2002. However, this catch mainly comprised Octopus tetricus, a temperate species that occurs south of Shark Bay. In north-western Australia, octopus are not targeted by any commercial fishery and only minor quantities are retained. In 2001, the reported catch of octopus by prawn trawling in the Pilbara region was 2.6 t. This was a significant increase on all previous years, when annual catches by prawn trawling were each < 1 t, but the 2001 catch still represented a relatively minor quantity. In any case, octopus caught by prawn trawling are likely to be different species to deepwater octopus caught by fish trawling. Trap fishers in the Pilbara region occasionally catch octopus but discard all catches. The recreational catch of octopus in the Pilbara region is small, and is likely to consist of coastal species that are different to those taken by fish trawling in deeper water.

Echinoderms. Results of the bycatch survey suggest that approximately 15000 featherstars (Comaster spp., Lamprometra spp.), 4300 brittlestars (Ophiuroidae) and 8000 starfish (Fromia spp., Lamprometra spp.) are caught by the fishery per year. Catch rates of echinoderms were highest in Areas 1 and 5 of the fishery and similar at all depths of the survey.


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Evidence from various fisheries suggests that discarded echinoderms have a low probability of survival. Echinoderms suffer damage (e.g. arm loss) that can result in infection and mortality either immediately or several weeks after release. Also, live animals that are damaged or disturbed are vulnerable to predators. Trawling can significantly reduce the biomass of echinoderms in trawled areas, compared with non-trawled areas (e.g. Prena et al. 1999, Smith et al. 2000). However, the survival of discarded echinoderms can be improved by reducing the time they are exposed to air (Bergmann and Moore 2001).

Action: Although the impact of the fishery on non-retained macro- invertebrates is probably low, performance of the fishery in regard to bycatch of some species could be improved. It is proposed that a Code of Conduct be developed by industry to promote i) catch sorting procedures that maximise survivorship after release, ii) the release of berried female crustaceans, and iii) the release of species that fishers are not licenced to retain. A Bycatch Action Plan is being developed for the fishery that will detail the management of macroinvertebrate bycatch.


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5.3 GENERAL ENVIRONMENT

COMPONENT TREE FOR THE GENERAL ENVIRONMENT FOR THE PFTIMF

Fishing(eg trophic levels)

Sand infauna

Large epibenthos

Benthic Biota

Bait collection(not in this fishery)

Ghost fishing(not in this fishery)

removal of/damage toorganisms by


Translocation

addition/movementof biological material

Impacts on the biological community(eg trophic structure) through

Air quality(Fuel usage/Exhaust)

Water quality(Paper/plastic debris)

Other

Other Aspects of the Environment

A yellow box indicates that the issue was considered a high enough risk at the December 2002 Risk Assessment workshop to warrant a full performance report. A blue box indicates that the issue was considered a low risk, with no specific management required, and only a justification is presented.

5.3.1 REMOVAL OF/DAMAGE TO ORGANISMS 5.3.1.1 TROPHIC INTERACTIONS Rationale for Inclusion: The assessment of potential indirect ecosystem impacts that could result from the removal of target species by a fishery should always be assessed. Scalefish comprise the majority of the fishery catch. Most of these scalefish species are medium-sized, generalist carnivores, feeding on smaller fish, crustaceans and molluscs. There is no evidence that any of these species play a 'keystone' role in the ecosystem. Therefore,


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the majority of these species are similar in their trophic function and it is appropriate to consider the impact of total scalefish removals by the fishery.

ERA Risk Rating: Impact on the environment (C1 L6 LOW) Scalefish comprise the majority of the retained catch of the fishery, either as target or byproduct species. Scalefish also comprise the majority of the discarded catch. Discarded scalefish have a low probability of survival and so should be included in total removals by the fishery. In 2002, an estimated 3230 t of scalefish were caught (either discarded or retained) by the fishery. In addition, a total of 327 t of sharks/invertebrates were caught (either discarded or retained) by the fishery.

It is unlikely that total removals by the fishery would significantly disrupt trophic dynamics in the region. Most species in the scalefish catch are generalist carnivores and consume a wide range of fish and invertebrates from demersal habitats. Therefore, the impact of any reduction in scalefish predator abundance would be spread across many prey species. Also, there are other species of medium-sized carnivores in the Pilbara region that are not caught in significant quantities by the fishery and contribute to the total biomass of carnivores in the region. These non-target species play a similar trophic role to targeted species and would compensate for the effect of removals by the fishery.

It is possible that scalefish removals by the fishery have localised impacts in some Areas of the fishery that are open to trawling. However, overall catch rates of scalefish are stable in each Area which suggests that scalefish recruitment to the Pilbara region has not been affected by removals and that the total biomass of medium-sized, generalist carnivores in the region is probably being maintained at a level sufficient to maintain trophic function.

In a review of scientific studies on the effects of fishing on marine ecosystems, Jennings and Kaiser (1998) concluded that "where the functional and species diversity of fishes is relatively high, the indirect effects of fishing on the abundance of unfished prey species appears to be minor". Tropical marine waters, including the north-west shelf, are characterised by communities of high species diversity. In such systems, the overall effect of piscivores on their prey is substantial but the removal of one species, or a small group of species, is minor (e.g. Hixon 1991). In the Pilbara region, there is no evidence to suggest that the removal of scalefish by trawling has directly resulted in a significant trophic effect (i.e. extinction, appearance of new species or other measurable shift in ecosystem function). Examples of such "trophic cascades", which occur because fishing interferes with predator-prey (or herbivore-plant) interactions, are quite rare. Evidence to suggest a shift in the community composition on the north-west shelf due to fishing (Sainsbury et al. 1997) is thought to be associated with direct habitat removal by trawl gear rather than removals of target species.

Therefore, it was considered that the trophic impact of total removals the fishery was 'likely' to be 'minor', resulting in a risk rating of LOW.

Although the trophic impact of total removals by this fishery was rated as LOW, the Department of Fisheries recognises that an assessment of trophic impacts by fisheries at a regional level, rather than at the individual fishery level, would be beneficial. Consequently, the Department will investigate the development of research to identify


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any detectable changes in the structure of coastal fish communities in this region over the last 40 years.

5.3.1.2 SAND INFAUNA (MICROBENTHOS) Rationale for Inclusion: Sand is a habitat type over which trawling commonly occurs. During operation, trawl nets are preceded by otter boards and "sweeps" (metal wires), which skim over the sand and disturb demersal fish. Fish are herded by this gear and become trapped in the net. The sweeps are approximately 90 m long and disturb the upper 6 centimetres of sand in front of the net (Moran and Stephenson 2000). Some sand is also disturbed by bobbins that are attached to the ground rope of the net and allow the ground rope to roll over the sand. Bobbins are a maximum diameter of 400 mm and are set approximately every 1 m along the ground rope. Infauna associated with sand habitats may be disturbed by the actions of the boards, sweeps, bobbins and ground rope. The overall path of the trawl is approximately 55 m wide (i.e. the distance between the otter boards).

ERA Risk Rating: Impact on sand infauna (C1 L6 LOW) Within the trawl fishery, untrawled sand habitat occurs in closed areas (Zone 1, and Areas 3 and 6) and in locations adjacent to reef areas that are not trawled. Sand habitat also occurs north, south and inshore of the fishery boundary. All these areas provide undisturbed, local refugia for sand-dwelling fauna and are probably a source of recruitment to disturbed (trawled) sand habitats within in the fishery.

Trawling probably has limited negative impact on sand infauna and indeed is likely to have increased the area of habitat available to these communities. Sand habitats are naturally dynamic environments and resident infauna are adapted to cope with physical disturbances. Most of these organisms are small, short-lived and reproduce rapidly. Hence, infaunal communities of mobile sediments would be expected to be resilient to disturbance by trawling and recover rapidly (e.g. Kaiser et al. 1996). Collie et al. (2000) estimated that the recovery period of most sand infauna after disturbance would be approximately 100 d, and so these communities could typically sustain a frequency of disturbance of 2-3 times per year. Most sites within the Pilbara region are likely to be subject to trawling less frequently than this (Moran and Stephenson 2000). Therefore, it was considered that the impact of the fishery on sand communities was 'likely' to be 'minor', resulting in a risk rating of LOW.

5.3.1.3 LARGE EPIBENTHOS (MACROBENTHOS) Rationale for Inclusion: Large attached epibenthos such as sponges, sea fans, seawhips, soft corals, hard corals and coralline algae, may be damaged or removed by the actions of the otter boards, sweeps, ground rope or bobbins on the trawl nets.

During operation, trawl nets are preceded by otter boards and "sweeps" (metal wires), which skim over the bottom and disturb demersal fish and benthos. Fish are herded by


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this gear and become trapped in the net. The sweeps are approximately 90 m long and disturb the upper 6 cm of sediment in front of the net (Moran and Stephenson 2000). Bobbins, up to 400 mm in diameter, are set approximately every 1 m along the ground rope and are designed to allow the ground rope to roll over the bottom. Epibenthos may be disturbed by the actions of the boards, sweeps, bobbins and ground rope. The overall path of the trawl is approximately 55 m wide (i.e. the distance between the otter boards).

ERA Risk Rating: Impact on large epibenthos (C4 L4 HIGH) Demersal trawling is known to be destructive to large epibenthos. It has been estimated that communities of attached epibenthos in open areas of the fishery experience annual rates of trawl- induced mortality of between 0.5 and 20 % (Moran and Stephenson 2000). Sponges, soft corals and other large epibenthos provide adult habitat and nursery areas for invertebrates and fish, including some species targeted by the fishery. Some Lethrinus and Lutjanus species occur in inter-reef areas containing large epibenthos. Declines in catches of some of these target species, and increases in catches of other species such as lizardfish and threadfin bream, which are associated with sand habitats, have been linked to the loss of epibenthos habitats on the north-west shelf (Sainsbury 1997).

The rate of removal of epibenthos is related to the level of fishing effort. Therefore, current management measures that limit fishing effort within each Area not only constrain mortality of target species but also limit mortality on epibenthic communities. At most locations open to trawling, epibenthos mortality is estimated to be <10% per year (Moran and Stephenson 2000), which may allow recovery of some faster growing epibenthic species. However, this may not allow regrowth of large (i.e. >25 cm) epibenthos (e.g. large sponges), which are generally believed to recover slowly (>15 y) (Sainsbury 1997).

Closed (untrawled) areas (Zone 1, and Areas 3 and 6) within the fishery provide refugia for epibenthos. Sixty percent of the Pilbara demersal fish fishery (encompassing both trawl and trap fisheries) in the depth range 30-120 m, is closed to trawling. Depths of 120-200 m, which also occur in the fishery, are not considered here because these depths contain markedly different types of epibenthic communities to the shallower areas of the fishery and are probably of a different type to those being impacted by the fishery (J. Fromont pers. comm., P. Stephenson unpubl data). Beyond the boundaries of the fishery, untrawled habitats for epibenthic communities occur to the north, south and east. Within open Areas (Areas 1, 2, 4 and 5), numerous small remnants of undisturbed epibenthos may occur in locations adjacent to reef areas that are not trawled. Therefore, there are untrawled areas in the Pilbara region that provide local refugia for epibenthic fauna and may be a source of recruitment to areas disturbed by trawling.

Although the area of the fishery open to trawling is a relatively small proportion of the total area of the Pilbara region, it is currently uncertain what amount of the untrawled area is of comparable habitat composition to trawled areas. As a result of this uncertainty, the consequence of the fishery impacting on epibenthic communities in the areas where trawling operates was rated as 'major'.


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Assessment of the impact of the fishery on epibenthos is hindered by a lack of information about the distribution of habitats in the Pilbara region and, to a lesser degree, the recovery rates of epibenthic communities after disturbance. Until a better understanding of the distribution of these habitats in relation to trawling can be developed, a precautionary approach must be taken. Therefore, the likelihood of a major impact on epibenthos by the fishery was considered 'possible'. This resulted in a risk rating of HIGH.

Operational Objective To maintain a specified area of untrawled habitat within the fishery that is sufficient in size and composition for maintaining epibenthic communities within the Pilbara region.

Justification: Fish trawling is known to affect epibenthic organisms. Therefore, the closure of some areas to trawling is required to ensure th at the more fragile or vulnerable species are sustained in the region. Areas that are closed to trawling will provide refugia for benthic fauna. In addition, the presence of viable and undisturbed epibenthic communities will provide fish habitat. Closed ar eas may assist in maintaining biodiversity and be a source of recruitment in the Pilbara region. In the future, additional objectives relating to the management of epibenthos in trawled areas may be developed. This will be subject to gaining a better unde rstanding of recovery rates of epibenthic species and the distribution of epibenthic habitats in the Pilbara region. Indicators Current indicator:

The area within the Pilbara demersal fish fishery (encompassing both trawl and trap fisheries) that is closed to trawling at depths of 30 to 120 m.

Future indicators:

1) The area of sponge/soft coral-dominated habitat within the Pilbara demersal fish fishery (encompassing both trawl and trap fisheries) that is closed to trawling.

2) Total area of the fishery that is open to trawling and subject to high cumulative mortality of epibenthos.

3) Proportion of the trawl catch comprising species that are dependent on sponge/soft coral-dominated habitats.


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Performance Measures Current: The total area of the Pilbara demersal fish fishery (encompassing both trawl and trap fisheries) that is closed to trawling is 80%. The total area of the Pilbara demersal fish fishery between depths of 30 m and 120 m should remain at or below the current level of 60%.

Future:

1) The total area of sponge/soft coral-dominated habitat in the Pilbara region (i.e. combined trap and trawl fisheries) that is closed to trawling should remain at or below [level to be reviewed].

2) The total area of the fishery that is open to trawling and subject to an average, annual mortality level that exceeds 10%, over a period of 5 years, should remain at or below [level to be reviewed].

3) The proportion of the trawl catch comprising species that are dependent on sponge/soft coral-dominated habitats (e.g. lethrinids, lutjanids) should remain at [level to be reviewed].

Justification: Current: Areas that are closed to trawling provide refugia for macrobenthic fauna. While the distribution of habitat types in the Pilbara region remains unclear, the amount of untrawled area should be maintained at a relatively high level to ensure that some suitable areas of habitat for epibenthic communities are maintained. A non -trawled area of >70% of the whole Pilbara demersal fish fishery (or 60% of the fishery at depth s of 30-120 m), is a relatively large proportion in relation to other trawl fisheries at similar latitudes (e.g. <40% of the Queensland East Coast Trawl is closed to trawling). In the absence of detailed information about the distribution of epibenthic com munities in the Pilbara region, it is considered that depths of 30 -120 m are most likely to contain suitable habitats for the species of epibenthos impacted by the fishery. Future: 1) Sponge/soft coral -dominated habitats have been identified as important habitats for many target species, including lethrinids and lutjanids. Declines in catches of these target species in the 1970s and 1980s have been linked to the loss of epibenthos habitats on the north -west shelf (Sainsbury 1991). However, the distributio n of these habitats in the Pilbara region is unclear. It is not known whether the areas of the fishery that are currently closed to trawling contain significant amounts of such habitats. The suitability of current closed areas as refugia for epibenthos wil l be re -assessed when more information about the distribution of habitats in the Pilbara region is available. 2) Moran and Stephenson (2000) estimated that most of the fishery is subject to epibenthos mortality rates of < 10% per year. However, they ident ified a small


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number of "hotspots" in the fishery where annual epibenthic mortality due to trawling often exceeded 20%. It may be desirable to restrict such "hotspots" to a few locations and maintain lower (<10%) levels of annual mortality across the majority of the fishery. Low levels of fishing mortality may allow recovery of some faster growing species of epibenthos, which could provide functional fish habitat in open areas of the fishery, even in the absence of slower growing epibenthic species. 3) The abundance of fish species that are dependent on sponge/soft coral -dominated habitats is an indirect measure of the abundance of these habitats in the Pilbara region. Data collected by Sainsbury (1987, 1988, 1991) indicated that major trawl -induced changes in habitat (from epibenthos - to sand-dominated) are reflected in fish trawl catch composition on the north -west shelf. Data Requirement for Indicator Current: Data about the distribution of trawling effort is available from a VMS, which monitors fishing time and location. VMS has been operational in the fishery since 1998.

Future:

1) CSIRO is currently preparing maps of benthic habitats in the Pilbara region. Mapping information is being compiled from various sources (scientific surveys, commercial fisheries, anecdotal reports). Epibenthos is being mapped from photographic data collected between 1983 and 1997. Future bycatch surveys of the fishery, similar to the bycatch survey conducted in 2002 (Stephenson and Chidlow 2003), will also contribute to an understanding of benthic habitat distributions in the Pilbara region and identify temporal trends in distribution and abundance of epibenthos in open areas of the fishery. It would be beneficial if future bycatch surveys were expanded to include observations of epibenthos distributions in closed areas. Woodside Petroleum has conducted video transects of selected areas of the bottom, associated with gas pipelines and drilling rigs in the Pilbara region. This footage may also contribute to knowledge of benthic habitat distributions.

2) VMS data about the distribution of trawling effort can be used to infer levels of epibenthos mortality in the fishery (Moran and Stephenson 2000). Annual mortality is generally between 0.05 and 20%, depending on location. However, the recovery rates of various epibenthic species are not currently known and so the impact of these mortality levels cannot be assessed. Research currently being conducted about the recovery rates of epibenthic species after trawling on the Great Barrie r Reef (e.g. Pitcher et al. 2000) may yield some estimates of recovery rates that can be applied in the Pilbara region.

3) Sainsbury (1987, 1988, 1991) observed major changes in catch composition in the Taiwanese trawl fishery that were linked to changes in habitat on the north-west shelf during the 1970s and 1980s. Initially, fish species associated with sponge/soft coral-dominated habitats (Lutjanus and Lethrinus) comprised 40-60% of the catch, and sand-associated species (Nemipterus and Saurida) comprised about 10% of the catch. By the mid 1980s, these proportions were approximately 10% and 25%, respectively. Over the same period, the catch rate of sponges fell from about 500kg/hour to only a


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few kg/hour. Results of Sainsbury could be used to develop meaningful trigger points for use in the analysis of catch composition in the Pilbara fishery. Catch data from the Pilbara fishery is available in the CAES database. In the future, monthly fisher returns, skipper logbooks and regular bycatch surveys will each provide catch composition data. Preliminary work to develop this type of indicator would involve a review of ecological literature to assign each retained species to a habitat type.

Evaluation Summary: Approximately 60% of the Pilbara demersal fish fishery (encompassing trawl and trap fisheries), at depths of 30-120 m, is closed to trawling and is intended to provide areas of refuge for benthic fauna. However, it is not known whether habitats in closed areas are comparable with those of open areas (i.e. are representative of the Pilbara region), or indeed whether closed areas contain any habitats suitable for epibenthic communities. The recent bycatch survey did not sample in closed areas. The total amount of closed area in the Pilbara region is large and so probably does contain some habitats suitable for epibenthic communities. Nevertheless, more data about the distribution of habitats in closed and open areas of the fishery is required to assess the effectiveness of closed areas as refugia for epibenthos.

In general, more data about the distribution of benthic habitats and the rates of recovery after trawling by various epibenthic species are needed to assess the impact of the fishery on epibenthic communities and to ensure that sufficient epibenthic communities are maintained within the Pilbara region.

Rates of epibenthic mortality. The mortality of large (> 20 cm) epibenthic species (mainly sponges, soft corals, gorgonians) has been estimated at 15.5% from a single demersal trawl pass (Moran and Stephenson 2000). Based on this estimate, fishing effort data obtained from VMS suggests that the fishery- induced mortality of epibenthos in areas of the fishery that are open to trawling is between 0.5 and 20% per year, depending on location (Moran and Stephenson 2000). More than 90% of the locations within trawled areas are subject to < 10% mortality, with only a few "hotspots" experiencing mortalities >15%. Mortality is highest in Area 1 of the fishery and lowest in Areas 2 and 4 (Table 20). However, recovery rates of these communities are unknown and large epibenthos may take >15 years to recover (Sainsbury et al. 1997).

Sponges are the dominant epibenthos component of the trawl catch in the Pilbara region (Wassenberg et al. 2002, Stephenson and Chidlow 2003). Wassenberg et al. (2002) estimated an average removal rate of 13.8% for sponges and 3% for other sessile megabenthos per trawl pass on the north-west shelf. Sponges are more vulnerable to removal by trawling than other organisms because of their rigid structure. Over 90% of more flexible organisms such as sea whips, seafans and alcyonarians, pass under the net (Wassenberg et al. 2002). Also, large sponges are more vulnerable to removal than small sponges. Approximately 10% of small (<300 mm), 25% of medium (301-500 mm) and 55% of large (<500 mm) sponges are dislodged per trawl pass. These rates of removal are dependant on the shape and flexibility of the sponge. In general, large lump-shaped sponges are most vulnerable to removal by trawling (70% removed per trawl pass) because they are relatively inflexible, compared with branching shapes (40% removal) (Wassenberg et al. 2002).


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Some sessile epibenthic species that are abraded or broken by trawl gear but remain attached to the substrate may survive, especially if wounds are relatively small. However, virtually all species are expected to die if brought to the surface and discarded (J. Fromont pers. comm.).

Table 20 Estimated annual rate of mortality of large (>20 cm) attached epibenthos within 6 x 6 nm grids within fishery Areas (from Moran and Stephenson 2000).

Area Annual mortality level of attached epibenthos

Zone 1 zero (area closed to trawling)

Area 1 mostly 5-20%

Area 2 mostly 0.5-5%

Area 3 zero (area closed to trawling)

Area 4 mostly 0.5-5%

Area 5 mostly 0.5-10%, but 15-20% at a few location

Area 6 zero (area closed to trawling)

The 2002 bycatch survey. Large epibenthos caught during the survey mainly comprised sponges, soft corals, seafans and coralline algae (Table 20). Material retained in the net may represent as little as 4% of the epibenthic fauna that is actually dislodged by the trawl (Moran and Stephenson 2000). Nonetheless, significant quantities of sponge and other material were collected in the survey. Interestingly, catch rates of epibenthos, including medium and large-sized sponges, were highest in Area 1. This area is trawled more intensively and has the longest history of trawling of all Areas of the fishery. These results indicate that medium and large sponges are still present in the fishery, even in areas where trawling has been continuous over several decades. However, these data alone are not conclusive. A full interpretation of the survey data will require an understanding about habitat composition in closed areas and estimates of community recovery rates.

During the bycatch survey, hard coral was the least frequently caught of all epibenthic taxa (Table 20). Generally, the fishery does not operate over rocky or coral reefs because such hard structures damage trawl gear, and so the fishery has limited impact on hard corals or reef communities.


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Table 21 Annual fishery catch* of each epibenthic species, estimated from

results of 2002 Bycatch Survey (Stephenson and Chidlow 2002), and locations of highest catch rates in the survey area.

(*these estimates may be as little as 4% of the actual catch). Catch measured as number of individuals (seafans, seawhips, soft coral) or pieces (sponges, hard coral, coralline algae). 'small' = can be lifted in 1 hand, 'medium' = can be lifted by 1 person, 'large' = can be lifted by 2 people. Name Total catch Locations of highest catch rates in fishery

Small sponges 83655 similar catch rates in all Areas; higher catch rates in shallow water.

Medium sponges 28418 higher catch rates in Area 1; higher catch rates in shallow water.

Large sponges 5538 higher catch rates in Area 1; higher catch rates in shallow water.

Hard coral 598 similar catch rates in all Areas; higher catch rates in shallow water.

Soft coral (Dendronephthya spp.) 4212 similar catch rates in all Areas & depths.

Coralline algae (Corallinaceae) 17017 higher catch rates in Areas 4 & 5; higher catch rates in deep water.

Seafans (Subergorgonia spp., Ctenocella spp.) 22269 similar catch rates in all Areas; higher catch rates in deep water.

Seawhip (Junceela spp.) 910 found only in Areas 1 & 2; mainly in deep water.

Robustness: Low - Moderate The effectiveness of closed areas as refuge sites for epibenthos cannot be assessed without some understanding of the distribution of habitat types within the fishery. Some habitat maps are available for the Pilbara region (CSIRO, unpublished data). However, it is not yet possible to determine whether closed Areas are generally representative of the Pilbara region or indeed provide any suitable habitats for epibenthic communities. The total area closed to trawling in and around the fishery is large, and so is likely to contain at least some suitable habitats. The robustness of this strategy will be improved when habitat distributions are known, and the suitability of closed areas can be assessed.

Most of the areas of the fishery open to trawling are not trawled heavily, i.e. annual rate of epibenthos mortality is <10%. This may at least allow faster growing epibenthic species to persist in trawled areas and provide some habitat for fish. Recent data from the 2002 bycatch survey indicated that open areas do indeed contain epibenthic organisms, including medium and large sponges. However, data about the distribution of habitats in open and closed areas of the fishery, and rates of recovery after trawling for various species are required to fully interpret these observations.


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Fisheries Management Response Current: The main strategy currently employed to manage the impact of the fishery on epibenthic communities is to limit the total area of the fishery that is exposed to trawling. The PFTF Interim Management Plan specifies that Zone 1 and Areas 3 and 6 are currently closed to fishing. This results in only 40% of the Pilbara demersal fish fishery (encompassing trawl and trap fisheries), between depths of 30 and 120 m, being open to trawling.

The PFTF Interim Management Plan also specifies the level of effort that can occur within each of the open Areas. This measure is intended to limit mortality of target species but indirectly also limits mortality on epibenthic communities.

Future: Future research and management action will depend on the results of habitat mapping surveys. It is anticipated that some mapping data will soon be available from CSIRO, which has conducted extensive surveys in the region. In addition, it is proposed that a bycatch survey of the fishery be conducted every 5 years, which would include data on epibenthos catches. Data from regular surveys will provide information about the distribution of epibenthic communities in open areas of the fishery and about temporal trends in the abundance of epibenthic fauna.

If CSIRO mapping data suggest that areas in and adjacent to the fishery that are currently closed to trawling are providing adequate refuge sites to maintain epibenthos in the Pilbara region, then no further management action may be required.

If research by CSIRO, on the north-west shelf and in Queensland, yield estimates of epibenthic recovery rates that can be applied in the Pilbara region, then sustainable levels of fishing mortality could be estimated for various epibenthic species. This may allow meaningful targets for epibenthic mortality in the fishery to be set. If so, then the strategy of area-based, effort adjustment that is currently used to manage impacts on target species could also be used to manage impacts on epibenthic communities.

The maintenance of some amount of epibenthic fauna in open areas of the fishery may be desirable because of the positive effect on catch rates (Sainsbury et al. 1997). Many target species are strongly associated with habitats dominated by large epibenthos. Trawl catch rates of target species in the Pilbara region are highest in areas where epibenthic communities are abundant (Newman et al. 2002, Stephenson and Chidlow 2003). Although communities in open areas may be less diverse and may be dominated by fast growing species (relative to communities in closed areas), they may still provide functional fish habitat and so enhance catch rates.

Actions if Performance Limits are Exceeded: If the specified area of trawled ground within the Pilbara region is exceeded, or if CSIRO mapping data suggest that existing closed areas are not sufficient to maintain epibenthos in the Pilbara region, then alternative or additional areas may be closed to encompass more suitable refuge sites. Ability to implement these actions is provided through the FRMA and the Pilbara Fish Trawl Fishery Interim Management Plan 1997. The authority to adjust trawl effort is held by the Minister of Fisheries via authority to amend the Management Plan.

If mapping data from CSIRO is found not to be adequate to assess the suitability of closed areas, then research proposals will be developed and funding sought to obtain additional information. Regular bycatch surveys that are proposed to occur in open


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areas of the fishery could be expanded to also examine epibenthic communities in closed areas.

The impact of the fishery on epibenthic communities in the Pilbara region is currently unclear. If habitat maps and other data are not available within 3 years to adequately assess the impact of the fishery on epibenthic communities, then precautionary management action should be taken to reduce this impact. The following actions are available to the fishery:

Proposed action 1. Particularly diverse epibenthic communities have been observed at a depth of approximately 80 m (J. Fromont pers. comm.). Consideration should be given to extending closed Area 3 (which currently only extends to a depth of 70 m) to the 100 m depth contour (i.e. the boundary of area 6) to provide additional refuge areas at this significant depth.

Proposed action 2. The 2002 Bycatch Survey suggested that a relatively large amount of epibenthos existed in Area 5. This area is currently relatively lightly fished by the trawl fishery. Consideration could be given to closing Area 5 to trawling, possibly in exchange for i) opening some 100-120 m depth sections of Area 6 to trawling, and/or ii) closing all trawled areas to trapping. Under this proposal, the trap fishery, which is less destructive to benthos, could gain exclusive use of Area 5. This would eliminate trawling impacts and preserve remaining benthos in Area 5, as well as spatially segregating trap and trawl sectors in the Pilbara region.

Proposed action 3. Future research could be conducted to investigate modifications to trawl gear that may reduce trawl- induced mortality of epibenthos. These modifications include:

i) a reduction of the distance between otter boards (currently ~55 m). The distance between the otter boards is effectively the width of the trawl path.

ii) a reduction in maximum bobbin diameter. Wider bobbins allow trawl nets to travel over rougher ground. Small bobbins would essentially restrict trawls to sandy areas and exclude them from areas of complex structural habitat.

Comments and Actions Limited data, collected by CSIRO and Department of Fisheries, suggests that Area 1 contains a more diverse array of habitat types than other Areas of the fishery. There is a need for additional research to obtain a more detailed understanding of the distribution and recovery rates of epibenthic communities in the Pilbara region.

External Driver Check List Cyclones regularly disturb benthos in the Pilbara region. Deepwater benthic habitats are also disturbed by the construction of pipelines and drilling rigs. "Disturbance" includes damage or removal from physical action or turbidity.

Impact of Taiwanese pair-trawl fleet. Prior to the development of the present domestic fish trawl fishery, the Pilbara region was subject to relatively heavy levels of trawling by the Taiwanese pair-trawl fleet during the 1970s and 1980s. This activity is


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known to have significantly reduced the amount of epibenthos (sponges, alcyonarians, gorgonians) in the region (Sainsbury 1991). However, the exact abundance and distribution of epibenthic organisms prior to the commencement of Taiwanese trawling is not known. Therefore, the impact on epibenthic communities by the current fishery cannot be assessed relative to the pristine (untrawled) state of these communities.

The current trawl fishery operates at lower levels of effort and uses lighter gear than the Taiwanese fleet and so is likely to be less damaging to epibenthos. Therefore, it is possible that some recovery of the communities has occurred since the commencement of the current fishery.

Full recovery of epibenthos in the Pilbara region to a pristine state may be impossible in some areas, even where current fishing effort is reduced to zero, if the Taiwanese fleet irreversibly altered the ecosystem. If the Taiwanese fleet did significantly reduce epibenthos abundance, and if the rate of regrowth of these communities is very slow, then recovery may be difficult in areas open to trawling, even under low levels of current effort. This is especially the case for larger (i.e. >25 cm) epibenthos, which may take >15 years to recover (Sainsbury et al. 1997).

5.3.2 ADDITION OR MOVEMENT OF BIOLOGICAL MATERIAL 5.3.2.1 TRANSLOCATION Rationale for Inclusion: Some vessels used in the fishery travel between regions and could potentially be a vector for exotic species and diseases.

ERA Risk Rating: Impact on the environment (C4 L1 LOW) Five vessels operate in the PFTIMF. In addition to fishing in the Pilbara region, one vessel may also travel to Carnarvon to fish for scallops and 2-3 vessels may travel to the Kimberley region to fish for prawns. Each vessel travels to Perth approximately once per year for maintenance. The hulls of vessels moving between regions could provide an opportunity for translocation of organisms. However, hulls are regularly anti- fouled. Also, the Leeuwin current flows along the length of the WA coastline, transporting biological material and resulting in a high level of connectivity between regions. Therefore, vessels in the fishery are unlikely to translocate organisms beyond the range of dispersal that would occur through natural processes. Therefore, although the impact of translocation of exotic pests or diseases would be 'major', the likelihood of this event is 'remote'. This results in a risk rating of LOW.

Vessels operating in the fishery do not use ballast water. Trawl nets are used only in the Pilbara region and are disposed of on shore, either at Point Samson (in the Pilbara region) or in Perth. The fishery does not use bait. Therefore, there is no translocation of exotic species and diseases by the fishery via these vectors.


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5.3.2.2 DISCARDING/PROVISIONING Rationale for Inclusion: The discarding of fish, as non-retained bycatch, by the fishery results in a food source that would not normally be available to other organisms.

ERA Risk Rating: Impact on general environment (C1 L6 LOW) Approximately 1000 t of scalefish, 150 t of elasmobranches and a small quantity of invertebrates are discarded by the fishery per year (Stephenson and Chidlow 2003). There is little processing of the scalefish catch onboard and so few fish waste products (e.g. heads, fins and guts) are discarded at sea. Waste products arise from the retained shark catch, which is generally processed at sea. Shark waste product (i.e. heads, guts) is equivalent to 37% of the landed catch and was approximately 25 t in 2002.

Some discarded elasmobranches and many discarded invertebrates (especially crustaceans and molluscs) have a high likelihood of survival after release and so do not contribute to "provisioning" by the fishery. The entire Pilbara demersal fish fishery covers an area of approximately 52000 km2. If the total biomass of discards by the fishery is 1150 t per year, then an average of 22 kg of biomass are discarded per km2 per year across the entire fishery. At present, only 27% (14040 km2) of the fishery is actually subject to trawling. If only this functional area of the fishery is considered, total discards result in an average of 82 kg of biomass being discarded per km2 (or 0.08 g per m2) per year.

The majority of biological material discarded by the fishery is whole fish, which sinks soon after being discarded. Therefore, discards provide an additional food source for pelagic and benthic communities. While floating on the surface or in the water column, discards are mainly scavenged by dolphins and sharks. Dolphins are highly selective about the type of discarded fish that they consume (McShane et al. 1999), and they may allow much of the discarded material to sink and reach the seabed. On the bottom, discards are mainly scavenged by crabs and nemipterid fish ("threadfin bream") (Hill and Wassenburg 1990).

Discards occur over a wide area. Also, discards are likely to disperse as they sink in the water column due to currents, and so the impact of discarding will be diffuse. The average annual rate (82 kg per km2 of trawled area) of provisioning by the fishery is low, relative to the biomass of food sources naturally available to carnivores and scavengers in the region. Therefore, it was considered that the impact of discarding of biological material by the fishery was 'likely' to be 'minor', resulting in a risk rating of LOW.

The quantity of discards could be reduced if new markets could be developed for species that are currently discarded because they are of low value.


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5.3.3 OTHER ENVIRONMENTAL IMPACTS 5.3.3.1 EXHAUST FUMES Rationale for Inclusion: Trawl vessels produce exhaust fumes. ERA Risk Rating: Impact on general environment (C0 L6 NEGLIGIBLE) There are the equivalent of 4.3 full time vessels operating in the fishery. The fishery covers an area of 14980 nm2. The impact of exhaust fumes released by the fishery over this area is 'likely' to be 'negligible'. This results in a risk rating of NEGLIGIBLE.

5.3.3.2 DEBRIS Rationale for Inclusion: Fish trawling operations produce small quantities of plastic and paper debris that must be disposed of. ERA Risk Rating: Impact on general environment (C0 L6 NEGLIGIBLE) The fishery operates under an international code of practise that specifies the appropriate disposal of debris at sea. The obligations of fishers under this code are clearly displayed on each vessel. Plastics are not discarded at sea by the fishery. Paper debris may be discarded at sea, but only when vessels are >12 nm from shore. There are the equivalent of 4.3 full time vessels operating in the fishery, which covers an area of 14980 nm2. The impact of any paper debris, which is readily biodegradable, being released by the fishery over this area is 'likely' to be 'negligible'. This results in a risk rating of NEGLIGIBLE.


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5.4 GOVERNANCE

COMPONENT TREE FOR THE GOVERNANCE

Managementeffectiveness

Arrangements

Compliance

Information

Resources

Allocation

Proactivemanagement

Management Consultation

Assessment &Reviews

Reporting

Fisheries law

Access rights

OCS arrangements

Integrity

Transferefficiency

LIcence registry

Legal Framework

Department ofFisheries

Central policyAuditing

Other Agencies

Government

codes of conductparticipationseafood healthpeak bodiesReportingskilled people

Industry

watchdog rolerepresentativeness(proven constituency)

others (NGOs etc)

Governance

Nb- no generic components have been removed from the tree but only those boxes that are yellow will be reported in this application.

5.4.1 DEPARTMENT OF FISHERIES – MANAGEMENT 5.4.1.1 MANAGEMENT EFFECTIVENESS (OUTCOMES) Rationale for Inclusion: The effectiveness of management arrangements in the PFTIMF are ultimately measured by assessing the outcomes of various strategies employed to manage this fishery. Effort has been controlled since the inception of the interim management plan in 1997. Additionally, there are also temporal (seasonal), spatial (area) closures, and gear controls. In sections 5.1.1.1, 5.1.1.2 and 5.1.2.1, the catches for individual demersal scalefish species were discussed and analysed, therefore this section will look at the cumulative catch and assess whether current management arrangements are maintaining the total catch for all demersal scalefish species within an acceptable range. If the annual acceptable catch range of demersal scalefish is maintained, then the community’s expectation that variations in annual catch result only from annual changes in environmental conditions, or planned changes to the management of the level of commercial exploitation, and not from the depletion of the stock. Any large unexplained variation in catch is likely to be a reflection of a reduction in management effectiveness and therefore reduce the community’s confidence in the


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management of the resource and raise concerns about the on-going sustainability of the fishery. Operational Objective The commercial catch of the major species of demersal scalefish in the PFTIMF are maintained within a determined acceptable range on an annual basis.

Justification: If effective management arrangements are operational in the fishery (including the restrictions on effective effort levels, co mpliance with the regulations are being maintained effectively combined with our understanding of the size of the exploitable stock), then the actual total catch for the major demersal scalefish species caught should be very close to the total acceptable c atch. Any variation outside of the acceptable total catch range would elicit the need to explain the cause of this deviation and potentially result in changes to management arrangements. Indicator

The total catch compared to the historical acceptable range for the major demersal scalefish species in the Pilbara Fish Trawl fishery.

Performance Measure Under the current fishing effort levels, the catch projections for the Pilbara Fish Trawl fishery are that the total catch of major demersal scalefish species should be within the range of 1900 - 2200 tonnes. However, within this overall figure, consideration needs to be given to catches at the species level, particularly for red emperor, rankin cod and blue spot emperor (see Section 5.1). Justification: The justification for the individual levels for each demersal scalefish species is located in Section 5.1 Data Requirements for indicator The following data are required for this indicator: Data Requirement Data Availability Commercial catch and effort Yes – obtained annually Historical catch levels Yes – records available and accessible Level of fishing effort and fishing power

Yes – number of vessels, days fished, number of trawl hours used, areas of operations and activity and fishing power comparisons readily available.

Environmental indicators Yes – key environmental indicators readily available.


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Evaluation Summary: Historical catch and effort information indicate that the acceptable catch range for the major demersal scalefish species is being maintained in the trawl fishery. Breeding stocks of the short-lived species have been assessed as adequate. The spawning biomass of the longer-lived species is estimated to be satisfactory over the whole fishery, and it is likely that an adequate breeding stock exists outside of the trawl fishery. Therefore, the performance measure has not been triggered and current management strategies appear to be effective in achieving the overall objectives for the fishery. The total landings for the major demersal scalefish species for the 2002 season in the PFTIMF was 2310 tonnes. The 2310 tonnes included 278 tonnes of Red snapper, 353 tonnes of Blue spot emperor, 363 tonnes of threadfin bream, 211 tonnes of flagfish, 99 tonnes of Goldband snapper, 79 tonnes of Red emperor and 17 tonnes of Rankin Cod. In addition 180 tonnes of by-product was retained including 68 tonnes of Shark and ray. Robustness: Medium / High The data required for the indicators in most cases are readily available. However, the changes in fishing power and fleet efficiency through time need to be evaluated and considered in these analyses to ensure that the measures continue to be relevant. Fisheries Management Response The management measures imposed to achieve the objective for the total catch (see above) also serve to achieve the objective for the maintenance of spawning stock for the major demersal scalefish species caught at or above a level, which minimizes the risk of recruitment over fishing. Historically, variations in catch outside of the acceptable range have been explained either in terms of increased fishing effort, increased fishing efficiency or seasonal environmental factors. The response to these issues has been to reduce fishing effort (e.g. spatial or temporal closures) with a focus on limiting the exploitation of breeding stocks and to develop a predictive model to take account of environmental factors such as sea surface temperature and ENSO, El Nino and La Nina events.


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The Department of Fisheries is doing further work to improve the measurement of fishing efficiency and understanding of the relationship between stock recruitment and environmental factors and catch. The Department will continue to use input controls to adjust for variations in fishing efficiency. Furthe rmore, the introduction of the VMS has led to the ability of the Department of Fisheries to collect and analyze data on the area utilized by this fishery and individual fishing boat activity. Actions if Performance Limit is Exceeded: If the catch were outside the range of expected values then a review of the causes would be undertaken. This review would examine why the acceptable catch range was not met. If this variation is not explained by changes in effort or environmental variations or a peculiarity of fleet dynamics and behaviour then strategies that offer further protection to the breeding stock will be considered. These strategies which could be employed within the season or at the start of the next season include:

• Further reductions in the total effort expended in the fishery through a reduction in the length of the fishing season or within seasonal closures.

• Additional area closures. Comments and Actions While the Department has been able to maintain the catch of the major demersal scalefish species within acceptable levels, it continues to work on improving and refining the methods used to determine breeding stock estimates. The use of GIS systems for analysing data has also commenced. External Driver Checklist Environmental factors such as climatic changes, cyclonic activity impacting habitat, ocean currents and sea surface temperatures are known to impact upon recruitment and therefore are likely to impact the level and productivity of breeding stocks. 5.4.1.2 MANAGEMENT ARRANGEMENTS Rationale for Inclusion: In Western Australia, the Fish Resources Management Act 1994 (FRMA) governs the management of all fisheries. The FRMA provides for the creation of Management Plans, Orders, Regulations, Ministerial Policy Guidelines and Policy Statements. The Act sets out the objects for the sustainable management of fish resources in Western Australia, and provides the framework for developing and implementing management plans for each of the State’s fisheries. The Pilbara Fish Trawl Interim Managed Fishery Management Plan 1997 is a set of rules for the fishery and includes inter alia clauses concerning the spatial boundaries of the fishery, gear restrictions, temporal closures and transferability arrangements. The authority to take demersal scalefish by trawl in the Pilbara region for a commercial purpose is provided for by a Pilbara Fish Trawl interim managed fishery permit.


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Table 22 Objects of the FRMA. Objects

(1) The objects of this Act are to conserve, develop and share the fish resources of the State for the benefit of present and future generations.

(2) In particular, this Act has the following objects- (a) to conserve fish and protect their environment; (b) to ensure that the exploitation of fish resources is

carried out in a sustainable manner; (c) to enable the management of fishing, aquaculture

and associated industries and aquatic eco-tourism; (d) to foster the development of commercial fishing

and recreational fishing and aquaculture; (e) to achieve the optimum economic, social and other

benefits from the use of fish resources; (f) to enable the allocation of fish resources between

users of those resources; (g) to provide for the control of foreign interests in

fishing, aquaculture and associated industries; (h) to enable the management of fish habitat

protection areas and the Abrolhos islands reserve.

Operational Objective In consultation with the industry members and other stakeholders, the Department periodically reviews the legislation, regulations and Ministerial policy guidelines to ensure the management framework remains relevant and aligned with the management objectives. To have an effective and understandable plan for the management of this fishery with all of the 10 principles covered within the suite of arrangements developed for the fishery. Justification: Management arrangements ultimately enable the sustainable exploitation of a natural resource where the potential to harvest the resource could exceed the ability of the resource to replenish itself. The development of rules can restrict the potential to ha rvest at an appropriate level, and management arrangements can define processes within which access to the resource can be allocated to competing user groups (including natural ecosystems).


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Indicator The extent to which the FRMA, FRMR, Management Plans, Ministerial Policy Guidelines and other management arrangements allow for the timely setting of appropriate effort levels and resource allocation in the fishery. The extent to which the management plan and supporting documentation addresses each of the issues and has appropriate objectives, indicators and performance measures, along with the planned management responses

Performance Measure The FRMA, FRMR, Management Plans, Ministerial Policy Guidelines and other management arrangements should allow fo r the timely setting of appropriate effort levels and resource allocation in the fishery in 100% of incidents. Evaluation Formal evaluation of the interim management arrangements of the PFTIMF is nearing completion. Preliminary investigations suggest that management arrangements for the fishery are adequate in that little potential exists for fishermen to activate inappropriately high levels of effort that could place the target demersal scalefish resource at risk. The performance of current management arrangements can be evaluated on two levels – the micro level, i.e. the relevance of individual clauses/regulations and the role they play; and on the macro level, i.e. the relevance of the plans, endorsements or arrangements as a whole and the role that they play. Current Performance against each of the areas required within the “plan”3:

1. An explicit description of the management unit – The management unit for Pilbara Fish trawl fishery is explicitly described at Clause 19 of the Pilbara Fish Trawl Interim Managed Fishery Management Plan 1997.

2. The issues addressed by the plan –The issues that need to be addressed by

the Pilbara Fish Trawl fishery management arrangements have been examined thoroughly and are documented within the 8 ESD component trees and their reports.

3. Descriptions of the stocks, their habitat and the fishing activities – the

Pilbara Fish Trawl fishery demersal scalefish stocks are described in Section 2.1 and the fishing activities are described in Section 2.2.

3 “Plan” – includes all management arrangements


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4. Clear operational (measurable) objectives and their associated performance measures and indicators – These are now located in Section 5 for each of the major issues.

5. Clearly defined rules, including what actions are to be taken if

performance measures are triggered – For each of these major issues, the management actions that are planned to be taken if performance limits are exceeded are now articulated in Section 5.

6. Economic and social characteristics of the groups involved in the fishery –

A brief articulation of the economic and social characteristics of the fisheries is located in Section 3.3 and there is to be a greater level of detail accumulated during the process of completing the remainder of the ESD components.

7. Management and regulatory details for the implementation of the actual

management plan – The regulations relating to the Pilbara Fish Trawl Fishery are located in the Pilbara Fish Trawl Interim Management Plan, and the FRMR (A set of which has been provided to EA).

8. The reporting and assessment arrangements – These arrangements are

documented in Section 5.4.4.1 and include annual reporting against current agreed performance limits and targets and a five yearly review of these arrangements and assumptions.

9. How and when reviews of the plan will occur (including consultation

mechanisms). – The FRMA clearly sets out how the process for the review of any management plan must occur. A review of the Pilbara Fish Trawl fishery plans and management arrangements is currently underway with a view to developing a more comprehensive set of management arrangements for all Pilbara fisheries.

10. A synopsis of how each of the ESD issues are being addressed – A synopsis

of ESD issues has been compiled within the Overview Table of this report. Robustness: High The management plans and related legislation have provided a diverse but reasonably complete set of fisheries management legislation. The fact that the management arrangements are contained within legislation provides a high degree of stability with respect to how the fisheries are managed. The process for achieving management plan changes is well understood by the majority of stakeholders and the system is flexible enough for the management process to respond to change in stimuli. Fisheries Management Response The Department has successfully administered the management plans and related legislation to achieve and pursue the stated objectives for the PFTIMF. Changes have occasionally occurred to address key concerns or issues. The Management Plan was revised in 1999 with a 33% effort reduction in area 1 and 9% in areas 4 and 5.


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Furthermore, in the 2002 season, the effort in areas 1 and 5 were reduced by 10% in order to further conserve fish stocks. In addition, in 2002 amendments to the Management Plan limited the over-run time in any area to no more than 48 hours per licence. This has reduced the extra amount of effort expended in the fishery. A Bycatch Action Plan is also being developed for this fishery concurrently with the Department of Environments and Heritage ecological sustainability assessment. The Bycatch Action Plan is intended to compliment the ESD process, rather than duplicate it. Development of the Bycatch Action Plan is regarded as essential in progressing the PFTIMF from interim management arrangements to a fully managed fishery status. It is also expected to play a central role in the Pilbara Trawl Fishery being able to demonstrate ecological sustainability when the exemption from the requirement to obtain a permit to export marine species ceases. Preliminary work on the bycatch action plan for the PFTIMF commenced in 2002. In March 2002 a discussion paper entitled “Bycatch Action Plan in the Pilbara Fish Trawl Interim Managed Fishery” was sent to stakeholders for review. It is also proposed that the permit holders in the PFTIMF develop a Code of Conduct. Potentially, this Code of Conduct could incorporate the Bycatch Action Plan. It would be used to promote preferred fishing methods that minimize bycatch and maximize the survival of released species. It would also encourage the reporting in voluntary logbooks of the catch of selected retained and discarded species to improve the quality of environmental data associated with the fishery. It is proposed to address this issue at the 2003 annual management meeting for the Pilbara Trawl Fishery licensees. Comments and Actions The PFTIMF is managed in a consultative way and responds readily to changed circumstances. However, fishers are often resistant to change. This means that before the fishers accept effort-reduction methods, they require substantial evidence of the need for such measures. While most fishers have a very high level of confidence in the Department’s research activities, some members of the industry demand certain knowledge before accepting the need for change and can be skeptical of research findings no matter how statistically valid. Individual fishers’ views can understandably be greatly influenced by their own experiences and observations while fishing that sometimes may give them a contrary view of the state of the fishery. Nonetheless, there is generally a very good relationship between fishers and the Departmental research scientists and most will accept the advice of the researchers. The commercial success of the fishery also appears to have encouraged many fishers to be somewhat risk averse and inclined to a very conservative approach to managing the fishery (particularly given their level of investment). While this encourages an attitude to avoiding risks to the sustainability of the fishery, it can also sometimes make some fishers resistant to changes in fishing rules that are designed to ensure sustainability. There is also sometimes a failure to recognize that the success of the fishery is in part due to a history of adaptive management. Proposed changes are often questioned on the basis that “as the fishery is operating successfully, why should any changed be necessary or contemplated?”


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External Driver Check List

• Potential resistance of fishers to support Department initiated management arrangements.

• Potential reluctance of Minister to exercise power. • Potential reluctance of fishers to develop or support an Industry Code of

Conduct. 5.4.1.3 COMPLIANCE Rationale for Inclusion: Effective compliance is vital to achieve the management objectives of any fishery. This involves a mix of sea and land patrols, radar watches and since the plan’s inception in 1997, the VMS. The ability to conduct at sea compliance patrols on the Pilbara coast is limited because of patrol boat size and availability. However, these fisheries are monitored by VMS, and therefore there is little need for compliance vessels to monitor spatial and temporal boundary infringements, as the vessels position is automatically communicated to the Department’s compliance section at all times. Six offences were detected in 1999 and 3 breaches of major provisions of the plan in 2001/2002 resulted in Prosecution Briefs being submitted. Two of the three incidents involved vessels exceeding time unit quotas and one incident involved a vessel failing to nominate prior to entering the Area 6 closure. Operational Objective To have sufficiently high levels of compliance with the FRMA, FRMR and various fish trawl management plans, regulations, conditions [endorsements] and notices. Justification: The activities of the participants in the fishery need to be sufficiently consistent with the management framework and legislation in order to make it likely that the expected outcomes and objectives of the fishery will be achieved. Indicators The levels of compliance with the legislation, including the estimated level of boundary infringements, and compliance with conditions of licence. Degree of understanding and acceptance of rules governing the operation of the Pilbara Fish Trawl fishery by licensees and the broader fishing community. Performance Measure That 100% of VMS polls record vessels within allocated temporal and spatial boundaries.


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Data Collection Requirements and Processes Random inspections of vessels at sea and port. Ongoing collection of data on illegal activities. Comparative data on the relative effectiveness of certain compliance techniques. VMS and other vessel surveillance data. Evaluation Sea patrols and radar watches are also conducted on a random basis through the seasons. Compliance operations are mainly focussed on maintaining the integrity of the areas within the fisheries. The compliance staff also conducts annual licence and gear inspections both at sea and at port. With the introduction of VMS into these fisheries in 1997, it was expected that random patrol activities would decrease over time, while targeted patrols investigating specific incidences would become the major focus of patrol activities. Robustness: Medium The difficulties in identifying every illegal activity will remain. However, as the PFTIMF is monitored continuously by VMS, there is little risk of major temporal (seasonal) or spatial boundary infringements, and offenders are immediately notified and dealt with accordingly. Fisheries Management Response Despite the relatively low levels of compliance work being done in the PFTIMF, the Regional Services Branch of the Department continues to gather intelligence on suspected breaches within this fishery. Comments and Actions The Department will continue to provide high standard compliance service within budgetary and resourcing constraints to the Pilbara fisheries. It is expected that the completion of a compliance risk assessment for the fishery will enable the Department to better direct resources to further increase the effectiveness of the limited compliance activities. In 1997 the VMS was introduced into the PFTIMF, which enables the Department of Fisheries to monitor a vessel’s location, direction and speed. This allows for particular attention to be paid to the surveillance of nursery areas.


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External Driver Check List

• Changes to technology that may facilitate an increase the level of non-compliance.

• Changes to non-Fisheries legislation (National Competition Policy) may impact upon the Department’s ability to restrict activities in a way that assist compliance (e.g. processor receival restrictions).

5.4.1.4 ALLOCATION AMONG USERS Rationale for Inclusion: Within the broad context of ESD, the issue of how fish resources can best be shared between competing users requires consideration. In Western Australia, the Integrated Fisheries Management Review Committee (IFMRC) was established to develop a strategy to integrate the management and sustainable use of fish resources. The report produced by the Committee in November 2002 proposes an alternative management framework and a set of guiding principles for allocating fish stocks to ensure optimal benefits are realised for the WA community. The Department of Fisheries recognises that the integrated fisheries management approach applies to the demersal finfish fishery. In addition to the commercial fishery there is also a large recreational component for demersal scalefish in the Pilbara. There can also be non-extractive (i.e. Department of Conservation and Land Management, dive operations etc) interests in the resource and its related ecosystem, which also need to be considered in the management process. In recent years, the Pilbara region has experience significant growth in recreational fishing activity, with a booming fishing-based tour and ecotourism industry based around the region’s reputation as remote and pristine. Recreational fishing participation in marine waters between Onslow and the WA/NT border is estimated at about 12% of the State’s recreation anglers, or 70,000 anglers per year generating 1 million fishing days. A recent creel survey conducted between December 1999 and November 2000 has confirmed that the Pilbara region is a major focus of recreational fishing. Charter activity is also significant with 85 fishing tour and 5 ecotour licences issued for the north coast bioregion. Operational Objective To ensure that allocation decisions aim to maximize the overall benefit to the Western Australian community from the use of fish stocks and take account of the economic, social, cultural and environmental factors. Indicator The level of resource sharing conflict between users and the level of participation of interested groups in any focused resource sharing process.


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Data Requirements for Indicator In order to ensure satisfactory allocation among user groups the following data is required: Data Requirement Data Availability

Breeding stock abundance estimates Yes –not measured directly but data from

catch rates and size/age structure are consistent with sufficient oceanic stock to maintain ongoing recruitment.

Estimate of recreational catch Yes – measured in the 12 month creel Pilbara Recreational Fishing Survey in December 1999 and November 2000 estimated at 300 tonnes.

Estimate of projected growth of recreational snapper fishing in Shark Bay

Yes – can be estimated based on existing growth trends in recreational fishing and overall population growth.

It should also be noted that cost is another major factor when considering various management options. For example, a TAC, which incorporated a recreational ‘allocation’ may satisfy sustainability issues, but would be prohibitively expensive in terms of the management/administration of the recreational ‘quota’. Furthermore, the Department is currently awaiting the outcomes of the integrated fisheries, management review process in terms of processes that need to be used for resource allocation mechanisms among user groups and timeframes etc. Evaluation Preliminary creel survey results of recreational fishing in the Pilbara region of Western Australia suggest a total recreational catch of all scalefish species at approximately 300 tonnes, excluding charter vessel catches. This equates to approximately 10% of the commercial demersal scalefish catch for the region during the same period. Spangled emperor, Red emperor, barramundi, threadfin salmon species and mackerel species were taken by both the recreational and commercial sectors. Recreational fishing records from charter boats were not included in the survey. However, a logbook has been developed to collect catch and fishing effort information from tour operators and these data will be provided in future years. Robustness: Medium At present, while there is no specific allocation made to the recreational sector, the current level of recreational take is considered sustainable. However, catch and release of unwanted demersal scalefish (including undersize) might be having an additional impact on stocks given the preliminary results of the post capture mortality rate study.


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It should also be noted that a significantly increased recreational take would prompt a reassessment of current management arrangements for both recreational and commercial sectors. Fisheries Management Response Scientific information to support recreationally fished stock management in the north coast bioregion has come largely from previous Department of Fisheries studies focused on commercial fisheries. This research has provided good biological data on the major Lethrinid species (nor-west snappers), the red emperor and some related Lutjanid species (cods and coral trout), in the North West Shelf sector. A three-year research project on mackerel species is now being developed and will provide detailed biological and fishery data on these important recreational species. A major project, which commenced in July 2000, is collecting baseline data on the inshore finfish species targeted by recreational anglers across the north coast bioregion. In addition, a collaborative project is being undertaken with Murdoch University to provide biological data on the species subject to shore-based fishing by both recreational and commercial fishers. To estimate coral catch for recreational stock management purposes, a 12 month creel survey of recreational boat and shore based fishing from Exmouth Gulf to Broome, was undertaken between December 1999 and November 2000. The results from this study will be complemented by data from the National Recreational Fishing Survey undertaken during 2000/2001. These data, integrated with the long run commercial CAES databases and the current fishery independent projects, will provide the basis for ongoing management of the most important recreational stocks in this region. Comments and Actions Through the processes already established, the Department will continue to promote the integration of fisheries management across all user groups. To this end, the Department has a number of initiatives related to improving the governance and allocation and reallocation. An Integrated Fisheries Management Policy was released in 2000. This policy has been followed up by the formation of the IFMRC, which was required to report directly to the Minister on the most appropriate framework to try and achieve the integrated objectives of resource allocation in the state. In November 2002, the Committee released its report to the Minister. It is expected that the Minister would finalise his determinations on the new framework in 2003. External Driver Checklist Resource sharing issues being raised with the Minister independently of the IFMRC recommended process.


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5.4.2 DEPARTMENT OF FISHERIES – CONSULTATION 5.4.2.1 CONSULTATION (INCLUDING COMMUNICATION) Rationale for Inclusion: The FRMA has certain requirements with regard to consultation that must be undertaken in the course of managing fisheries. The management of the PFTIMF is based around a robust consultation and communication process. There are sections in the FRMA that relate to the development of management plans (Section 64) and to the amendment of a management plan (Section 65). Given that the Pilbara Fish Trawl fishery already has a working management plan, Section 65 is the most relevant.

Section 65 of the FRMA states:

Section 65. Procedure before amending management plan

(1) A management plan must specify an advisory committee or advisory committees or a person or persons who are to be consulted before the plan is amended or revoked.

(2) Before amending or revoking a management plan the Minister must consult with the advisory committee or advisory committees or the person or persons specified for that purpose in the plan.

(3) Despite subsection (2), the Minister may amend a management plan without consulting in accordance with that subsection if, in the Ministers opinion, the amendment is –

(a) required urgently; or

(b) of a minor nature

(4) If –

(a) the Minister amends a management plan; and

(b) the amendment is made without consultation because it is, in the Minister’s opinion , required urgently,


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the Minister must consult with the advisory committee or advisory committees or the person or persons specified for that purpose in the plan as soon as practicable after the plan has been amended.

Each year in late October, the Department holds meetings with the PFTIMF licence holders. These meetings typically involve discussions about management, research and compliance issues in the fishery, and provide a forum for industry to raise concerns and/or ask questions of the Department concerning management arrangements. Operational Objective To administer a consultation process that is in accordance with the requirements of the FRMA and allows for the best possible advice from all relevant stakeholders to be provided to the decision maker (Minister/ED) in a timely manner. Indicators

• The Minister (or the Department on his behalf) conforms to the consultation requirements of the FRMA and the Management Plan.

• The level to which licensees and other stakeholders consider that they are adequately and appropriately consulted.

Performance Measures Proper consultation procedures have been followed in any amendment of the management plan.

Industry meetings held annually. Data Requirements

The views of industry collected from stakeholders at each annual meeting.

When an amendment is proposed, documentation of the formal consultation procedures. Evaluation Consultation on management of the PFTIMF is conducted in an open, accountable and inclusive environment where all sectors of the industry and the Department’s managers and researchers collectively identify and discuss appropriate courses of action.

Decision makers are provided with advice based on this consultation and reasons are provided for decisions that vary from consultation-based advice.


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Robustness: High The consultation process is very well understood with relatively high levels of participation from the various stakeholder groups. Fisheries Management Response The Department is attempting to improve communication links with industry in the PFTIMF through regular correspondence and encouraging communications with the fishery manager. Given the remote location of many of the operators, it can be logistically difficult and costly to undertake field trips and plan meeting dates more than once every year. Comments and Actions The Department will continue to provide a commercial fisheries management officer who coordinates and further develops the consultation process for the PFTIMF. External Driver Check List Despite the aforementioned consultation processes that are in place, disaffected parties may still seek to use political avenues to further their cause.

5.4.3 DEPARTMENT OF FISHERIES - REPORTING 5.4.3.1 ASSESSMENT AND REVIEWS Rationale for Inclusion: It is important that the community is sufficiently informed on the status of fisheries, given that fisheries utilise a community resource. It is also important that the outcomes of the fisheries management processes administered by the Department for the PFTIMF are available for review by external parties. The reports that are currently developed annually include: the State of the Fisheries Report, the Annual report to the Auditor, the ESD report, and this application to DEH. There is also a longer-term plan to have the entire system of management audited by the WA Environmental Protection Agency (EPA). Operational Objective To continue to report annually to the Parliament and community on the status of all fisheries including the PFTIMF and to prepare a framework for reporting on ESD for all Western Australian fisheries.


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Indicators The extent to which external bodies with knowledge on the management of fisheries resources have access to relevant material and the level of acceptance within the community. Performance Measure General acceptance of the management system by the community. Data Requirements The majority of data required to generate reports are already collected in the course of pursuing resource management objectives. The Department conducts an annual survey of the community with respect to the community’s opinion on the status of the State’s fisheries and attitudes to the performance of the Department. Evaluation The Department has implemented more then one process to report on the performance of this fishery and in doing so has acted to ensure that the community has access to this information. In addition to this base level reporting, continual development of the management process will see the fishery undergo regular independent audits ensuring that the evaluation of the management arrangements in these fisheries is robust. The Department also undertakes formal stakeholder opinion surveys. The Department has been the recipient of a number of awards for excellence for its standard of reporting - Premiers Awards in 1998, 1999 for Public Service excellence, Category Awards in Annual Reporting in 1998, 1999, 2000; Lonnie Awards in 2000, 2001 and 2004. Current Reporting Arrangements for this fishery include: State of Fisheries There is annual reporting on the performance of the fishery against the agreed objectives within the “State Of The Fishery Report”. The document is available in hard copy format but is also available from the Department’s web site in PDF format. Annual Report A summary of this report is presented within the Department’s Annual Report and is used in some of the Performance Indicators that are reviewed annually by the OAG. ESD The Department is currently completing a full ESD report (of which the material presented in this application is a subset) that will cover not only the environmental


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aspects of the fishery but the full social and economic issues. Once completed this too will be available from the web site. Reports to Industry Each year, the status of the resource and effectiveness of current management are presented to industry in a series of meetings in major population centres in the Pilbara Region and the Perth Metropolitan area. Robustness: High Fisheries Management Response Current: For many years the Department has produced substantial and high quality documents that report on the operation of the Department and the status of its fisheries – these reports are the Annual Report and the State of the Fisheries. Future: The Department is working with the EPA to prepare a framework for reporting on ESD for all Western Australian fisheries. It is proposed that this framework will be linked to a regular audit cycle involving the EPA and periodic reporting to the OAG. The Department is working to combine the processes for reporting to the States and the Commonwealth and believes that this can best be achieved by using a Bilateral Agreement with DEH under the EPBC. Comments and Actions The assessment and review processes already established together with proposed external review processes should ensure that there would be many opportunities for the appropriateness of the management regime and the results it produces to be reviewed. External Driver Check List The assessments provided by independent review bodies and the community.

5.4.4 DEPARTMENT OF FISHERIES – LEGAL FRAMEWORK 5.4.4.1 OCS ARRANGEMENTS Rationale for Inclusion: The Pilbara Fish Trawl Fishery operates in Commonwealth waters but within the 200 metre isobath and therefore is managed by the State under the Offshore Constitutional Settlement 1995 (OCS) Operational Objective To uphold the existing jurisdictional arrangements for the management of this fishery.


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Indicators Approaches from the Commonwealth Government to alter the existing OCS. Performance Measure Maintenance of the existing responsibility of the State for the management of the fishery. Data Requirements None specific Evaluation The current jurisdictional arrangements are appropriate given the operations of the Fishery are within 200m isobath and the good track record that exists under these arrangements for the management of these fisheries. Robustness Very high. Fisheries Management Response The Department has successfully managed the Pilbara Fish Trawl Fishery for many years and sees no reason to alter the jurisdictional arrangements that currently exist. Comments and Action No action required. External Driver Check List Pressure to change any of the OCS arrangements.


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6. REFERENCES Allen GR 1985. Fishes of Western Australia. Pacific marine fishes Book 9. TFH

Publications, Neptune City.

Allen GR 1997. Marine fishes of tropical Australia and south-east Asia. Western Australian Museum, Perth. 292 pp.

Allen GR 1985. FAO species catalogue. Vol. 6. Snappers of the world. An annotated and illustrated catalogue of lutjanid species known to date. FAO Fisheries Synopsis No. 125 Volume 6. Rome, FAO. 1985. 208p.

Bergmann M and Moore PG 2001. Mortality of Asterias rubens and Ophiura ophiura discarded in the Nephrops fishery of the Clyde Sea area, Scotland. ICES J Mar Sci 58:531-542.

Blaber SMJ, Brewer DT and Harris AN 1994. Distribution, biomass and community structure of demersal fishes of the Gulf of Carpentaria, Australia. Aust J Mar Freshwat Res 45:375-396.

Broadhurst MK 1998. Bottlenose dolphins, Tursiops truncates, removing by-catch from prawn-trawl codends during fishing in New South Wales, Australia. Marine Fisheries Review 60:9-14.

Carpenter KE and Niem VH (eds) 2001. FAO species identification guide for fishery purposes. The living marine resources of the Western Central Pacific. Volume 5. Bony fishes part 3 (Menidae to Pomacentridae). Rome, FAO. Pp. 2791-3380.

Casey JG and Natanson LJ 1992, Revised estimates of age and growth of the sandbar shark (Carcharhinus plumbeus ) from the western North Atlantic. Can J Fish Aquat Sci 49:1474-1477.

Clucas I 1997. The utilisation of bycatch/discards. In Clucas I and James D (eds) 'Papers presented at the technical consultation on reduction and wastage in fisheries, Tokyo, Japan. 28 October-1 November, 1996. pp 25-44. FAO Fisheries Report 547 (Suppl.) 338 pp.

Chilvers BL and Corkeron PJ 2001. Trawling and bottlenose dolphin social structure. Proceedings of the Royal Society of London, Series B: Biological Sciences 268:1901-1905.

Collie JS, Hall SJ, Kaiser MJ and Poiner IR 2000. A quantitative analysis of fishing impacts on megafauna of Georges Bank. Marine Ecology Progress Series 155:159-172.

Compagno LJV 1984. FAO species catalogue. Vol 4, sharks of the world. An annoted and illustrated catalogue of sharks species known to date. Part 1 – Hexanchiformes to Lamniformes: viii, 1-250. Part 2 – Carcharhiniformes: x, 251-655. FAO Fisheries Synopsis 125: 1-655.

Dawson CE 1985. Indo-Pacific Pipefishes (Red Sea to the Americas). Gulf Coast Research Laboratory, Ocean Springs, Mississippi, USA. 230pp.


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APPENDIX 1 ACRONYMS CAES Catch and Effort Statistics System DEH Australian Government Department of the Environment and Heritage ED Executive Director of the Department of Fisheries EPA Western Australia Environment Protection Agency EPBC Environment Protection and Biodiversity Conservation Act 1999 ESD Ecologically Sustainable Development FRDC Fisheries Research and Development Corporation FRMA Fisheries Resources Management Act 1994 FRMR Fisheries Resources Management Regulations 1995 JASDGDLF Joint Authority Southern Demersal Gillnet and Demersal Longline Fishery NCSF North Coast Shark Fishery NDSMF Northern Demersal Scalefish Managed Fishery NPF Northern Prawn Fishery KPMF Kimberley Prawn Managed Fishery OAG Office of the Auditor General OCS Offshore Constitutional Settlement PFTIMF Pilbara Fish Trawl Interim Managed Fishery PTMF Pilbara Trap Managed Fishery TEDs Turtle Exclusion Devices VMS Vessel Monitoring System WA Western Australia WAFIC WA Fishing Industry Council WCA Wildlife Conservation Act 1950 WCDGDLF West Coast Demersal Gillnet and Demersal Longline Fishery


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APPENDIX 2 DETAILS OF CONSEQUENCES TABLE

Level Ecological

Negligible General - Insignificant impacts to habitat or populations, Unlikely to be measurable against background variability Target Stock/Non-retained: undetectable for this population Byproduct/Other Non-retained: Area where fishing occurs is negligible compared

to where the relevant stock of these species reside (< 1%) Protected Species: Relatively few are impacted. Ecosystem: Interactions may be occurring but it is unlikely that there would be any

change outside of natural variation Habitat: Affecting < 1% of area of original habitat area No Recovery Time Needed

Minor Target/Non-retained: Possibly detectable but little impact on population size but none on their dynamics.

By-product/Other Non-retained: Take in this fishery is small (< 10% of total) compared to total take by all fisheries and these species are covered explicitly elsewhere.

Take and area of capture by this fishery is small compared to known area of distribution (< 20%).

Protected Species: Some are impacted but there is no impact on stock Ecosystem: Captured species do not play a keystone role – only minor changes in relative abundance of other constituents. Habitat: Possibly localised affects < 5% of total habitat area

Rapid recovery would occur if stopped - measured in days to months.

Moderate Target/Non-retained: Full exploitation rate where long term recruitment/dynamics

not adversely impacted By-product: Relative area of, or susceptibility to capture is suspected to be less than

50% and species do not have vulnerable life history traits

Protected Species: Levels of impact are at the maximum acceptable level Ecosystem: measurable changes to the ecosystem components without there being a major change in function. (no loss of components) Habitat: 5-30 % of habitat area is affected.

:or, if occurring over wider area, level of impact to habitat not major Recovery probably measured in months – years if activity stopped

Severe Target/Non Retained: Affecting recruitment levels of stocks/ or their capacity to

increase By-product/Other Non-retained: No information is available on the relative area or susceptibility to capture or on the vulnerability of life history traits of this type of species. Relative levels of capture/susceptibility greater than 50% and species should be examined explicitly. Protected Species: Same as target species Ecosystem: Ecosystem function altered measurably and some function or

components are missing/declining/increasing outside of historical range &/or allowed/facilitated new species to appear.

Habitat: 30- 60 % of habitat is affected/removed.

Recovery measured in years if stopped


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Major Target/Non retained: Likely to cause local extinctions By-product/Other Non-retained: N/A

Protected Species: same as target species Ecosystem: A major change to ecosystem structure and function (different dynamics now occur with different species/groups now the major targets of capture)

Habitat: 60 - 90% affected Recovery period measured in years to decades if stopped.

Catastrophic Target/Non-retained: Local extinctions are imminent/immediate

By-product/Other Non-retained: N/A Protected Species: Same as target Ecosystem: Total collapse of ecosystem processes.

Habitat: > 90% affected in a major way/removed Long-term recovery period will be greater than decades or never, even if stopped

application to the department of envrionment and heritage ...€¦ · application to the department...

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