Chapter 24 | Southern Bluefin Tuna Fishery | 359

24 Southern Bluefin Tuna Fishery

H Patterson, G Begg and M Hormis

Figure 24.1 Catch in the SBTF, 2010

Table 24.1 Status of the SBTF

Fishery status 2009 2010 Comments

Biological statusFishing mortality

Biomass Fishing mortality

Biomass

Southern bluefin tuna (Thunnus maccoyii)

Spawning stock biomass ~5% of unfished levels

Economic status (Fishery level)

Estimates of net economic returns not available Net economic returns are likely to be lower in 2009–10 (but still positive) as a result of lower catch and reduced prices. The overfished state of the stock undermines the economic status of the fishery.

Fishing mortality Not subject to overfishing Subject to overfishing Uncertain

Biomass Not overfished Overfished Uncertain

360 | Fishery status reports 2010

Table 24.2 Main features and statistics of the SBTF

Feature Description

Key target and byproduct species

Southern bluefin tuna (Thunnus maccoyii)

Other byproduct species None in the purse-seine fishery (see ETBF and WTBF chapters for longline byproduct species)

Fishing methods Purse-seine; pelagic longline: monofilament mainline gear (southern bluefin tuna is a byproduct in longline fishery); minor line (troll and poling)

Primary landing ports None; previously Port Lincoln, but the cannery closed in May 2010 and no product has been landed since

Management methods Output controls: individual transferable quotas, area restrictions to control incidental catches in the longline fishery

Management plan Southern Bluefin Tuna Fishery management plan 1995 (AFMA 1995) (amended 2010)

Harvest strategy No formal harvest strategy

Consultative forums Commission for the Conservation of Southern Bluefin Tuna (CCSBT), Southern Bluefin Tuna Management Advisory Committee (SBTMAC)

Main markets International: Japan—frozen, fresh

EPBC Act assessments:

—listed species (Part 13)

—international movement of wildlife specimens (Part 13A)

Current accreditation dated 19 October 2010

Current accreditation (Wildlife Trade Operation); expires 24 July 2013

Ecological risk assessment Level 1: Scale, Intensity, Consequence Analysis (SICA) completed on 207 species (Hobday et al. 2007)

Level 2: Productivity Susceptibility Analysis (PSA) completed on 193 species (Hobday et al. 2007)

Level 3: Sustainability Assessment for Fishing Effects (SAFE) completed on 83 species (Zhou et al. 2009)

Bycatch workplans Australia’s tuna purse seine fisheries bycatch action plan 2005 (AFMA 2005) Australia’s tuna and billfish longline fisheries, bycatch and discarding workplan, November 1, 2008 to October 31, 2010 (AFMA 2008)

Fishery statisticsa 2009 2010

Fishing season 1 December 2008 – 30 November 2009 1 December 2009 – 30 November 2010

Total allowable catch 5265 t 5265 t available, based on combined 8030 t TAC for 2010 and 2011

Catch Purse-seine: 5015 t

Pelagic longline: 227 t

Purse-seine: 3931 t

Pelagic longline: 160 t

Effort Purse-seine: 1180 hours; 140 shots Purse-seine: 417 hours; 78 shots

Fishing permits 96 SFR owners initially allocated quota at start of fishing season

97 SFR owners initially allocated quota at start of fishing season

Active vessels Purse-seine: 8

Longline: 21

Purse-seine: 6

Longline: 21

Observer coverage Purse-seine: 11 shots (7.9%)

Longline: 6.4% in ETBF, 8.5% in WTBF

Purse-seine: 8 shots (10.3%)

Longline: 3.6% in ETBF, 2.5% in WTBF

Real gross value of production (2009–10 dollars)

2008–09 Commonwealth fishery (all methods): $46.4 million

South Australia aquaculture: $161.5 million (farm gate value; includes Commonwealth input)

2009–10 Commonwealth fishery (all methods): $38 million

South Australia aquaculture: $102.2 million (farm gate value; includes Commonwealth input)

Allocated management costs 2008–09: $1.9 million 2009–10: $1.8 million

EPBC Act = Environment Protection and Biodiversity Conservation Act 1999; ETBF = Eastern Tuna and Billfish Fishery; SFR = statutory fishing right; WTBF = Western Tuna and Billfish Fishery a Fishery statistics are provided by calendar year unless otherwise indicated

Chapter 24 | Southern Bluefin Tuna Fishery | 361

24.1 BaCkGrounDSouthern bluefin tuna constitutes a single, highly migratory stock that spawns in the north-east Indian Ocean and migrates throughout the temperate, southern oceans. It is one of the most highly valued fish species for sashimi, especially in Japan, and is targeted by fishing fleets from a number of nations, both on the high seas and within the Exclusive Economic Zones of Australia, New Zealand, Indonesia and South Africa. Young fish (aged 1–4 years) move from the spawning ground (off north-western Australia, south of Indonesia) into the Australian Fishing Zone and southwards along the Western Australian coast.

Surface-schooling juveniles are found seasonally in the continental shelf region of southern Australia, but the proportion of the juvenile stock that migrates into this area is not known. Juvenile southern bluefin tuna are targeted in the Great Australian Bight by Australian purse seiners (figure 24.1), which predominantly take 2–3-year-old fish. Throughout the rest of its range, southern bluefin tuna is targeted by pelagic longliners, including domestic longliners operating along Australia’s east coast (figure 24.1). Longliners harvest all ages, from juveniles about 3 years old (~100 cm fork length; 20 kg whole weight) through to adults (12+ years old).

Table 24.3 History of the SBTF

Year Description

1930s Commercial fishing for southern bluefin tuna began off south-east Australia.

1950s Pole and live-bait fishing began for surface-schooling southern bluefin tuna (New South Wales and South Australia).

Early 1960s Global catch of southern bluefin tuna peaked at 81 605 t.

Pre-1979 Japanese vessels operated unregulated in what became the AFZ.

Early 1980s Clear signs that the southern bluefin tuna stock was overfished became evident.

1979 to 1997 Japanese longliners operated in AFZ under licence (Australia–Japan joint venture).

1982 Australia’s catch of southern bluefin tuna peaked at 21 500 t (most of the catch processed for canning).

1983 TAC of 21 000 t was introduced for Australian catch.

1984 Introduction of individual transferable quotas led to reduction in latent effort in New South Wales and Western Australia, and concentration of quota holdings in South Australia.

1987 Australia, Japan and New Zealand began trilateral discussions to set non-binding international management measures, including national allocations of 14 500 t (Australia), 23 150 t (Japan) and 1000 t (New Zealand).

1990 First trials of aquaculture (ranching) for southern bluefin tuna in South Australia.

1993 Australia, Japan and New Zealand developed informal, collaborative management arrangements and signed an international convention (to come into force in 1994).

1994 CCSBT was established—responsible for global management of the southern bluefin tuna stock.

Late 1990s Approximately a third of the global catch was not controlled by CCSBT. A lack of MCS mechanisms allowed large amounts of IUU fishing to remain unchecked.

1997 Japanese fishers were excluded from the AFZ following failure to agree on global TAC.

1998 to 2002 Failure to agree on global TAC or national allocations. Australia maintained TAC of 5265 t.

1998 Japan unilaterally embarked on its EFP, increasing its reported catch by 1464 t to 7500 t.

1999 Japan unilaterally conducted EFP, reporting a catch of 7554 t. Non-CCSBT catch, including 1464 t from Japanese EFP, was estimated to exceed 7400 t. Australia and New Zealand sought and obtained the prescription of interim measures by ITLOS to halt the Japanese EFP.

2000 Arbitral tribunal determined ITLOS did not have jurisdiction over EFP.

2001 Republic of Korea became a member of CCSBT.

362 | Fishery status reports 2010

Year Description

2002 Fishing Entity of Taiwan became a member of the Extended Commission.

2004 Philippines was formally accepted as a cooperating non-member of CCSBT.

2005 A nomination to list southern bluefin tuna as a threatened species under the EPBC Act was rejected by the then Minister for the Environment and Heritage.

2006 CCSBT revealed large, unreported catches of southern bluefin tuna from 1985 to 2005—some estimates exceeded 178 000 t (Polacheck & Davies 2008). Severe loss of confidence in the primary catch series used in stock assessment, and abandonment of the adoption of a management procedure (incorporating a rebuilding strategy) by CCSBT. CCSBT reduced the global TAC from 2007 to 2009 inclusive (to 11 810 t per year), including a reduced national allocation to Japan for 2007 to 2011, to be reviewed in 2011. South Africa and European Community were formally accepted as cooperating non-members of CCSBT.

2007 Southern bluefin tuna was nominated for listing as a threatened species under the EPBC Act.

2008 Indonesia became a member of CCSBT. CCSBT adopted MCS measures to eliminate IUU fishing (to be implemented in 2010). Spawning stock biomass was estimated to be <10% of pre-exploitation biomass (CCSBT 2008). CCSBT concluded there were no signs the stock had begun to rebuild; instead, historically low recruitment from 1999 to 2002 would lead to further declines in spawning stock biomass in the near future.

2009 CCSBT reduced the global TAC by 20% for 2010 and 2011 because the stock was estimated to be ~5% of unfished spawning stock biomass. Australia’s TAC was reduced to 8030 t for the next two years, with a maximum of 5265 t allowed in 2010. CCSBT agreed to implement a management procedure in 2011 to be used in TAC setting from 2012 and beyond. An interim rebuilding target of 20% of unfished spawning stock biomass was agreed.

2010 Southern bluefin tuna was listed as conservation dependent under the EPBC Act on 24 November 2010. CCSBT reviewed several potential management procedures, but none were adopted. Management plan was amended to accommodate the commercial trial of stereo-video in the Australian Farm Sector in 2011 and to provide for an extension of the live release trial.

AFZ = Australian Fishing Zone; CCSBT = Commission for the Conservation of Southern Bluefin Tuna; EFP = Experimental Fishing Program; EPBC Act = Environment Protection and Biodiversity Conservation Act 1999; ITLOS = International Tribunal for the Law of the Sea; IUU = illegal, unregulated and unreported; MCS = monitoring, control and surveillance; TAC = total allowable catch

24.2 THE 2010 FiSHErYNational annual catch allocations of southern bluefin tuna for 2010 were reduced following a decision by the Commission for the Conservation of Southern Bluefin Tuna (CCSBT) in 2009. The effective annual catch limits (after reductions were applied) for 2010 and 2011 were Australia—4015 t, Japan—2261 t, New Zealand—709 t, Republic of Korea—859 t, the Fishing Entity of Taiwan—859 t and Indonesia—651 t. Interim catch allocations for cooperating non-members for 2010 and 2011 were Philippines—45 t, South Africa—40 t, and the European Community—10 t. The effective annual global total allowable catch (TAC) for 2010 and 2011 is therefore 9449 t.

Australia set a two-year TAC of 8030 t for 2010 and 2011, with the catch in 2010 not to exceed 5265 t. Australia’s total catch for 2010 was 4091 t, the majority taken by the purse-seine fleet and about 4 per cent (160 t) taken by the longline fishery in the

Eastern Tuna and Billfish Fishery (ETBF). No southern bluefin tuna was taken in the Western Tuna and Billfish Fishery (WTBF) (figure 24.2). The 2010 catch is less than the 2009 catch (5242 t); this was the first year of the quota reduction. The global southern bluefin tuna catch up to 2009 is shown in figure 24.3.

In 2010, 6 purse-seine and 18 longline vessels contributed to the total catch. The observer program of the Australian Fisheries Management Authority (AFMA) aims to monitor 10 per cent of southern bluefin tuna fishing activities in compliance with CCSBT observer standards. In 2010, the purse-seine coverage was 10.3 per cent of sets. A coverage level of 7.7 per cent was achieved in the longline ETBF, south of 30°S, from May to September (the months in which southern bluefin tuna is usually caught), and 2.5 per cent was achieved in the longline WTBF.

Table 24.3 History of the SBTF – continued

Chapter 24 | Southern Bluefin Tuna Fishery | 363

1989−90 1993−94 1997−98 2001−02 2005−06 2009−100

1

2

3

4

5

6

Figure 24.2 Catch & TAC: southern bluefin tuna,Australian fishery

LonglineSurfaceQuota

Cat

ch (t

hous

and

tonn

es)

Figure 24.2 Southern bluefin tuna catch history (Australia), by financial year, 1989–90 to 2009–10

1955 1964 1973 1982 1991 2000 20090

10

20

30

40

50

60

70

80

90

Figure 24.3 Catch: southern bluefin tuna, global

OtherAustralia

Rep

orte

d ca

tch

(thou

sand

tonn

es)

Note: Total global catches exceeded reported global catches over

1985-2005; some scientists estimate unreported catches to have

surpassed 178 000 t over this period (Polacheck & Davies 2008)

Figure 24.3 Southern bluefin tuna catch history (reported global), 1952 to 2009

In 2009–10, the value of commercial production from the Commonwealth Southern Bluefin Tuna Fishery (SBTF) was $38 million (figure 24.4), which generates a farm gate value of $102.2 million after ranching. In real terms, this is 40 per cent lower than the 2002–03 value of $94.6 million and significantly lower than in earlier years. Recent exchange rate movements and competition from northern bluefin tuna farmed in the Mediterranean have reduced the price of southern bluefin tuna on the Japanese market (figure 24.4).

2003−04 2005−06 2007−08 2009−100

10

20

30

40

50

60

70

80

90

100

Figure 24.4 GVP: southern bluefin tuna, SBTF

Sold directInput to farm

GVP

(200

9−10

A$

milli

on)

Figure 24.4 Real GVP of southern bluefin tuna production, by financial year, 2002–03 to 2009–10

2003−04 2005−06 2007−08 2009−100

50

100

150

200

250

300

350

Figure 24.5 Real value of exports, SBTF

Fresh or chilledFrozen

Valu

e (2

009−

10 A

$ m

illion

)

Figure 24.5 Real value of southern bluefin tuna exports, by financial year and processing methods, 2002–03 to 2009–10

Australian logbook and observer data suggest that there is minimal incidental catch during purse-seine fishing for southern bluefin tuna. Longlining byproduct consists mainly of large pelagic fish, including substantial numbers of sharks (see chapters 22 and 25).

364 | Fishery status reports 2010

24.3 HarvEST STraTEGY

24.3.1 Harvest strategy description

The Commonwealth Fisheries Harvest Strategy Policy (HSP) is not prescribed for fisheries, such as the SBTF, managed by international management bodies. Significant work has been invested in developing a harvest strategy (or management procedure) for southern bluefin tuna. This management procedure is pending adoption by the CCSBT, and will include interim and long-term rebuilding targets and management objectives for the stock and will form the basis of setting the global TAC. The CCSBT has also agreed to an interim rebuilding target of 20 per cent of unfished spawning stock biomass.

24.3.2 Harvest strategy performance

Given the absence of an adopted CCSBT harvest strategy (or management procedure) for this fishery, no assessment is made against this criterion.

24.4 BioloGiCal STaTuS

24.4.1 SouTHErn BluEFin Tuna (Thunnus maccoyii)

Line drawing: FAO

Table 24.4 Biology of southern bluefin tuna

Parameter Description

Range Species: Mostly distributed between 30°S and 60°S in southern temperate oceans, excluding the eastern Pacific Ocean

Stock: Southern bluefin tuna constitutes a single, highly migratory pelagic stock.

Depth 0–500 m

Longevity 40+ years

Maturity (50%)

age: ~10–12 years

Size: 120–130 cm FL

Spawning season

September–April. A single-known spawning ground is located in the north-east Indian Ocean (10–20°S, 105–120°E).

Size Maximum: 225 cm FL; ~200 kg whole weight

recruitment into the fishery: ~55 cm FL; 3.5 kg whole weight (9–12 months of age)

FL = fork length Source: Gomon et al. (2008)

Stock assessment

In 2009, a revised operating model (the model used to assess the status of southern bluefin tuna based on a variety of data sources over a long period) was used to run various scenarios using different annual catch levels to determine the impact on the stock. All the scenarios gave results consistent with previous assessments in recent years; the stock remains at a very low level (approximately 5 per cent of unfished spawning stock biomass; 0.05SB

0) and well below the level that could Poling southern bluefin tuna, Jay Hender, BRS

Chapter 24 | Southern Bluefin Tuna Fishery | 365

produce maximum sustainable yield (CCSBT 2009). Recruitment during the past 20 years is estimated to be below the levels seen from 1950 to 1980. Recent trends in recruitment (since 2005) appear more positive, although poor recruitment from 2000 to 2002 is evident as weak year-classes, which will have a negative impact on the spawning stock. Given the state of depletion, model projections indicate that a significant recovery time is required for the stock.

Stock status determination

Given the spawning stock biomass of the stock is at a very low level, southern bluefin tuna remains overfished and subject to overfishing.

24.5 EConoMiC STaTuSAssessment of economic performance in the wild-catch sector of the SBTF is difficult because the wild-catch and aquaculture sectors are vertically integrated. Almost all southern bluefin tuna caught in Commonwealth waters are transferred to aquaculture farms off Port Lincoln in South Australia. The price paid for live fish at the point of transfer to these farms cannot be observed as operators are generally involved in both catching and grow-out operations. Consequently, GVP for the SBTF has to be estimated indirectly by adding fishing costs to an estimate of the fishery’s profit. The estimate of fishery profit is based on the value of the seasonal lease of southern bluefin tuna quota. In addition to GVP, and value of the seasonal lease quota, other available indicators of economic performance are, export prices, effort and catch rates.

The economic performance of the fishery in 2009–10 would have been affected by recent reductions in the TAC for southern bluefin tuna. In 2010, quota reductions were implemented, with the combined TAC for 2010 and 2011 set at 8030 t. AFMA allowed 5265 t to be taken in 2010, against which 4091 t was caught. Since 2005, the TAC has been caught annually. Therefore, it is likely that the combined TAC for 2010 and 2011 will also be caught.

24.5.1 Trade

The real value of Australian southern bluefin tuna exports decreased by 68.5 per cent between 2002–03 and 2009–10 (figure 24.5). Most of this decrease is attributed to reduced prices on the main Japanese market, combined with an increase in the exchange

rate, which has reduced the competitiveness of Australian exports. Since 2002–03, supplies to international markets from European tuna farms are also likely to have contributed to this decline. More recently, demand-side factors may have been a key driver of the decrease in prices on the Japanese market, particularly following the global financial crisis. In 2009–10, the real export price in the SBTF decreased by 30 per cent, from $18.40 per kilogram in 2008–09 to $14.03 per kilogram (2009–10 dollars). This continues a declining trend since 2003–04. The 2009–10 price was approximately half the 2003–04 price.

24.5.2 value of quota

The value a holder places on a unit of quota is related to the holder’s current and expected future profits from the fishery. In general, this implies that quota values can provide an indication of fishery profitability. In the SBTF, there is limited trade of quota among a small number of operators that undertake seasonal leasing to cover requirements to fish in other Commonwealth fisheries (e.g. ETBF). Given these characteristics, the value of quota may not be an accurate indication of profitability in the SBTF. However, movements in quota lease prices from season to season may still give a broad indication of relative profitability between fishing seasons.

Quota lease prices in the SBTF increased in 2009–10. This suggests an expectation of an increase in profit. However, since fishing costs are expected to have remained relatively constant, the decline in export prices suggests that these expectations may not have been met in 2009–10.

24.5.3 overall economic performance

The SBTF is a high-value fishery. Given the biological status of the southern bluefin tuna stock over the past decade, it is likely that a proportion of profits, at least at the global scale, have been generated by previous excessive fishing rather than harvesting at sustainable levels.

In recent years, prices have declined, reflecting increased competition from European farmed tuna and the reduced competitiveness of Australian exports due to the high value of the Australian dollar. The cost of fishing is likely to have decreased in 2009–10, following moderate declines in fuel prices, but fuel prices are still substantially higher than they were in 2002–03. Together, the economic indicators suggest that net economic returns (NER)

366 | Fishery status reports 2010

in the fishery are likely to have declined in 2009–10, but remained positive.

However, the very low biomass of southern bluefin tuna poses a risk to the future flow of NER from this fishery. Therefore, economic status could be improved in the SBTF through stock rebuilding.

24.6 EnvironMEnTal STaTuSThe CCSBT has several measures in place to mitigate the environmental impact of fishing, including mandatory use (by all members and cooperating non-members) of tori lines on southern bluefin tuna longline vessels fishing below 30°S to reduce seabird interactions. The CCSBT Scientific Observer Program has a target coverage level of 10 per cent for catch and effort in all fisheries. The CCSBT publishes education pamphlets and guides on seabirds and sharks for southern bluefin tuna fishers.

The CCSBT adopted the recommendation of the Working Group on Ecologically Related Species that all members and cooperating non-members:

>> implement international guidelines on sharks, seabirds and turtles (e.g. the guidelines of the Food and Agriculture Organization of the United Nations to reduce sea turtle mortality in fishing operations)

>> comply with all measures to protect ecologically related species (ERS) implemented by the Indian Ocean Tuna Commission (IOTC) and Western Central Pacific Fisheries Commission (WCPFC)

>> collect and report data on ERS to the CCSBT, which will share the data with the IOTC and the WCPFC.

24.6.1 Ecological risk assessment

An ecological risk assessment of the purse-seine fishery was undertaken for the SBTF. The Level 2 assessment indicated that only southern bluefin tuna and white shark (Carcharodon carcharias) were considered to be at high risk (Hobday et al. 2007). A Level 3 assessment (Sustainability Assessment for Fishing Effects [SAFE]) was also conducted on 83 non-target species (6 chondrichthyans and 77 teleosts) to determine the impact of southern bluefin tuna fishing on the sustainability of these species. The risk to the sustainability of these non-target species was assessed as low (Zhou et al. 2009). Given this outcome, the priority of the ecological risk management report is to respond to interactions with protected species (AFMA 2009).

24.6.2 Threatened, endangered and protected species

Southern bluefin tuna was listed as conservation dependent under the EPBC Act on 24 November 2010.

Sharks

The aim of the observer program is to monitor 10 per cent of both purse seine and longline catch. Based on the observer data, interactions between sharks and purse seines appear to be relatively rare. Observer data from 2003 to 2009 indicate one interaction with a hammerhead shark and one interaction with a mako shark during that period. Both sharks were released alive. No shark interactions were recorded in logbooks for 2010. Interactions with sharks using longline gear are discussed in chapters 22 and 25.

Marine mammals

In 2010, there was a single interaction with a threatened, endangered and protected species when an unidentified seal became entangled in the boat propeller of a vessel that was purse seining. The animal was released alive.

Feeder vessel at a pontoon, Katrina Phillips, DAFF

Chapter 24 | Southern Bluefin Tuna Fishery | 367

24.7 liTEraTurE CiTEDAFMA (Australian Fisheries Management Authority) 1995, Southern Bluefin Tuna Fishery management plan 1995, DAFF, Canberra, Federal Register of Legislative Instruments F2008C00099.

—2005, Australia’s tuna purse seine fisheries bycatch action plan 2005, AFMA, Canberra.

—2008, Australia’s tuna and billfish longline fisheries, bycatch and discarding workplan, November 1, 2008 to October 31, 2010, AFMA, Canberra.

—2009, Ecological risk management report for the Southern Bluefin Tuna Fishery, AFMA, Canberra.

CCSBT (Commission for the Conservation of Southern Bluefin Tuna) 2008, Report of the thirteenth meeting of the Scientific Committee, Rotorua, 5–12 September 2008, CCSBT, Canberra.

—2009, Report of the fourteenth meeting of the Scientific Committee, Busan, 5–11 September 2009, CCSBT, Canberra.

Gomon, M, Bray, D & Kuiter, R 2008, Fishes of Australia’s south coast, New Holland Publishers, Sydney.

Hobday, AJ, Dowdney, J, Bulman, C, Sporcic, M, Fuller, M & Ling, S 2007, Ecological risk assessment for the effects of fishing: Southern Bluefin Tuna Purse Seine Fishery, report for the AFMA, Canberra.

Polacheck, T & Davies, C 2008, Considerations of implications of large unreported catches of southern bluefin tuna for assessments of tropical tunas, and the need for independent verification of catch and effort statistics, CSIRO Marine and Atmospheric Research paper 023, CSIRO, Hobart.

Zhou, S, Fuller, M & Smith, T 2009, Rapid quantitative risk assessment for fish species in seven Commonwealth fisheries, report for the AFMA, Canberra.