tuvalu bottomfish project final biological …
TRANSCRIPT
P-151 94-07
TUVALU BOTTOMFISH PROJECT FINAL BIOLOGICAL ASSESSMENT
Pacific Islands Marine Resource Project Tuvalu Component
Project No 879-0020
Prepared by RDA International Inc under Contract No 879-0020-C-00-1 231-00
with USAIDRDOSouth Pacific
Prepared by Wayne Haight
RDA Marine Biologist
December 1994
RDA INTERNATIONAL INC 801 Morey Drive
Placerville California 95667-4411 Telephone (916) 622-8800 Facsimile (91 6) 626-7391
This report was made possible through support provided byUSAID under terms of Contract No AID-0020-C-O0- 1231shy00 The opinions expressed and conclusions reached here are those of the author and do not necessarily reflect the views of USAID
Hi
TABLE OF CONTENTS
Eage
10 EXECUTIVE SUMMARY1-1
20 INTRODUCTION 2-1
30 BIOLOGICAL ASSESSMENT 3-1 31 Hydrographic program 3-1 32 Research fishing 3-17 33 Biomass and MSY estimation 3-17
40 CONCLUSION 4-1
50 REFERENCES 5-1
iii
LIST OF TABLES
Page
Table 3-1 Length of 200 m isobath within the Tuvalu EEZ 3-3
Table 3-2 Total catch by number and weight (marketable species only) 3-18
Table 3-3 Unexploited biomass and MSY range for Tuvalu 3-19
LIST OF FIGURES
Page
Figure 2-1 Republic of Tuvalu EEZ 2-2
of Tuvalu
Figure 3-1 Survey areas of the islands banks and seamounts 3-2
Figure 3-2 Depth contour map of Luao Bank 3-4
Figure 3-3 3-dimensional profile of Luao Bank 3-5
Figure 3-4 Depth contour map of RDA Bank 3-6
Figure 3-5 3-dimensional profile of RDA Bank 3-7
Figure 3-6 Depth contour map of Talie Bank 3-8
Figure 3-7 3-dimensional profile of Talie Bank 3-9
Figure 3-8 Depth contour map of Hera Bank 3-10
Figure 3-10 Depth contour map of Takalo Bank 3-12
Figure 3-9 3-dimensional profile of Hera Bank 3-11
Figure 3-11 3-dimensional profile of Takalo Bank 3-13
Figure 3-12 Depth contour map of Kosciusco Area 3-14
Figure 3-13 Depth contour map of Bayonnaise Bank 3-15
Figure 3-14 Depth contour map of Macaw Bank Area 3-16
iv
ABBREv ATIONS
CPUE Catch per unit effort
EEZ Exclusive Economic Zone
FAD Fish aggregating device
GPS Geographical positioning system
GOT Government of Tuvalu
MRA Marine Resource Adviser
MSY Maximum sustainable yield
NAFICOT National Fishing Corporation of Tuvalu
NMI Nautical mile
PCC Project Coordination Committee
PIMAR Pacific Island Marine Resource
RDO Regional Development Office
SP South Pacific
USAID United States Agency for International Development
v
TUVALU BOTTOMFISH PROJECT FINAL BIOLOGICAL ASSESSMENT
10 EXECUTIVE SUMMARY
Twenty-nine iesearch cruises were completedduring the biological assessment phaseof the project using the Government of Tuvalu vessel the RV Manaui Thirteen different geographical areas were hydrographically surveyed and systematically fished Included in the areas surveyed were 2 previously unknown and uncharted seamountsRDA Bank and Takalo Bank which were located and hydrographically surveyed A total of 9981 kg of fish of 44 different species were caught during research fishingoperations Of this total 24 species were marketable with atotal weight of 7661 kgThree species Eteis carbunculus Etelis coruscans and Caranx lugubris made up the majority of catch by weight The average CPUE of all species was 555 kgline-hourand 405 kgline-hour for marketable species values similar to other regions in theSouth Pacific Based on hydrographic research survey results the total length of the 200 m contour (seamounts islands and banks) is estimated to be 376 nautical miles (nmi) within the Tuvalu EEZ (The area defined by the 200 m depth contour (isobath)has become a standard measure of bottomfish habitat useful in calculating the estimated biomass and fish stock and in comparing habitat size among various geographic areas throughout the South Pacific) The associated unexploited biomassof deep-water bottomfish is estimated to be 639 mt Estimated yield at MSY rangesfrom 64 to 192 mt Based on these MSY estimates it has been calculated that this fishery could potentially support about Avessels fishing on the distant seamounts and about 2 additional vessels fishing around Tuvalus islands
1-1
20 INTRODUCTION
The Republic of Tuvalu consists of nine emergent coral atolls and several submergedbanks lying between 4-140S latitude and 1720 E to 1760 VV longitude The Exclusive Economic Zone (EEZ) of the Republic of Tuvalu covers approximately 600000 km 2
(Figure 2-1) The Government of Tuvalu considers marine resources their mostimportant natural asset It realizes that while exploitation of deep-water bottomfish fishery resources could provide potential economic development tropical deep-waterbottomfish have a long life span slow growth rate and variable larval recruitmentwhich make these species highly susceptible to over-fishing Therefore to scale aviable long-term commercial fishery it is imperative that the sustainable yield of bottomfish stocks within the EEZ first be estimated Several approaches can be used to determine maximum sustainable yield (MSY) for an exploited commercial fisherydepending on the type quality and quantity of data available Most of theseapproaches depend on an extensive time series of catch-per-unit-effort (CPUE) data or a large sample of both CPUE and length data Unfortunately time and budgetconstraints precluded this type of research program and analysis for the Tuvaluan bottomfish stock However relative abundance and hydrographic data collected in this program allow the unexploited biomass within the EEZ to be estimated The range of MSY values can then be calculated for the unexploited stock
2-1
_ _
Figure 2-1 R
epublic of T
uvalu EEZ
tl
__ ___I _
_ _
_ I
---- _
S
- -
I i
_ _
_ _
2-2
0
30 BIOLOGICAL ASSESSMENT
31 Hydrographic program
Twenty-nine research cruises were completed during the assessment phase of theproject The Government of Tuvalu vessel the RV Manaui was used exclusively as the research platform Systematic surveys were conducted throughout the archipelago(Figure 3-1) to provide information on local bathymetry species composition lengthfrequency catch rates and depth distributions
One hundred one (101) data sets were compiled from the data collected during the biological assessment phase of the project The data were entered into database software in Tuvalu These data were subsequently sent to the RDA Marine Biologistfor analysis Statistical analyses were done using the SAS statistical packageHydrographic data were analyzed and plotted using a commercial digitizing templateand Quattro Pro and SURFER hydrographic plotting software
Hydrographic measurements were taken using a GPS positioning unit and a color sounding chromoscope From this data hydrographic chartlets of areas of potentialfishery habitat were produced and plotted Approximately 95 of fishable seamount and submerged bank habitat in the Tuvaluan Archipelago was surveyed byhydrographic measurements and research fishing During the course of fishing andhydrographic operations five small seamounts were located and charted (Figures 3-2 through 3-11) In addition the poorly charted submerged bank areas in the south ofthe archipelago (Kosciusco Bank Bayonnaise Bank and Macaw Bank areas) wereextensively surveyed (Figures 3-12 3-13 and 3-14) The hydrographic data were digitized using the electronic template to calculate the length of the 200 m contour foreach seamount or bank system Potential fishery habitat expressed as the length of the 200 m contour is given in Table 3-1
3-1
Figure 3-1 S
urvey areas of the islands banks and seam
ounts of Tuvalu
-CD
I 0
2
1r4pj
_ _
_ shy
oc
(S) epnjpe shy
Arrow
s denote survey areas
3-2
Table 3-1 Length of 200m isobath within the Tuvalu EEZ
Bank
Luao
Kosciusko-Martha-Niulakita
Macaw
RDA
Talie
Bayonnaise
Hera
Takalo
Roseb
Total (seamounts)
Total (islands)
Total (Tuvalu)
Isobath Length (nautical miles)
672
8047
2479
175
323
9562
965
1212
1331
24766
12820C
37586
The large seamount surface extending from Niulakita was included in the 200 m isobath measurement for Kosciusko Martha Bank was also included with the Kosciusko Bank b The isobath length for Rose Bank is presented here separately but it is sufficiently indistinguishable from Kosciusko Bank that it could as well have been included along with Martha Bank with the isobath length for Kosciusko Bank
C Reference Dalzell and Preston 1991
3-3
Figure 3-2 Depth contour map of Luao Bank
10 153
-10157
-10161
-l0165
-10169
-10173
-10177
j_
f_
L_
LUAO BANK
=shy
-_
_
Q
_
-10181 T
-10197 ---- - -0 F -10201
-179708 -179703 -179698 -179693
I oncitude (W) -179688
3-4 12
Figure 3-3 3-dimensional profile of Luao Bank
LUAO SANK
3-5 1
C
Figure 3-4 D
epth contour map o
f RD
A B
ank
I1A
-
_
_ __
7
-17 k
V___ I
C
4J
In
D 0
I
I
b
d
N
I
I
ii p
Nr-
IN
I
N
I
0
3-6
Figure 3-5 3-dim
ensional profile of R
DA
B
ank
w
z z lt
S-
let-
ci-d
ti-IC
O-
Z-
-ee-
ZS
-E
G-
60C-
5C
fshy
3-7
Figure 3-6 Depth contour map of Talie Bank
-6226
TALIE BANK
-6229 - - - -I -
-62 3 1
-( -6234 -7
i
-shy_
7 (NT--- -shy
_
-6237
-6240
S-6243
-62436-
_
I
-
- -
t
- -
- -
~ ~1~-
I
PI
--1 - - - -
shy
-I- - - -
-6249
176324 1763327 176330 1763-3 176336
Longitude 176339
(E) 176342 176345 1763
3-8
Figure 3-7 3-dimensional profile of Talie Bank
TeI Le Ben k
3-9
Figure 3-8 Depth contour map of Hera Bank
HERA BANK
-1215
0 -12160
Q
j 12169 - -
- 12 18 5 -179251 -179242 -179233 -179224 -1792 14
I r -179205 -179196
Longitude (W)
3-10
Figure 3-9 3-dimensional profile of Hera Bank
Hera Benk
3-11
Figure 3-10 Depth contour map of Takalo Bank
TAKALO BANK -1144
-1145 shy
-114
-114 0_49
- 115o0shy
-1151
-17961 -17960 -17959 -17958 -17957 -17956 -17955
Longitude (W)
3-12
Figure 3-1 1 3-dimensional profile of Takalo Bank
TekaIo Benk
C
Ic2
3-13
-1038
Figure 3-12 Depth contour map of Kosciusco Bank Area
KOSCIUSKO AREA
1042 + -1
-1046 -0
-1058-1054 -0 Cgt1 (j70
ci)i
-1067
-1071 L _ _j
- 1075 -- 1--
-1083 C __I
- 1087 fill 1 f
17937 17941 17945 17949 17953 17957 17961 17965 17969
Longitude (E) 3-14
-------
-----
Figure 3-13 Depth contour map of Bayonnaise Bank
BAYONNAISE BANK
-1158 ----- 190 -I I
I I
- --------- I
-1158 L ----- L-----GI
I -1108 ---- L- I -I I I
I I
K)I I
(f)-1188 K
-31198 -121 --------L--------L-------------shy
-J 0 K -1178 --- -- L ------- L----- -
1208------LI~p
00
-1218-- ------ L L __
II I I I I I I I
I-1228---------- -I
- L-- - 7 --- L II I II
I I
I I
-1238 -17989 -17979 -17969 -17959 -17949 -17939
Longitude (W)
3-15
Figure 3-14 Depth contour map of Macaw Bank Area
v-CAW BANK AREA
1060I -- I - L -I
I II
I I I-1060-----------shy
k I I II
oI
-o~1 - - - L
II
-1066ii~I amp )
-1065---- -
I I
-1067
I I I
-1069 -17926 -17925 -17924- - 7923 -17922 -17921 -17920 -17919 -17918
Longitude (W)
3-16
32 Research fishing
A total of 9981 kg of fish of 44 different species were caught Of this total 24 species were marketable with a total weight of 7661 kg (77) (Table 3-2) Three species Etelis carbunculus Etelis coruscans and Caranx lugubris made up the majorityof catch by weight The average CPUE of all species was 555 kgline-hour and 405 kgline-hour for marketable species These CPUE values are average by regionalstandards and probably represent the lower bound of a commercial CPUE range This is because research fishing is usually not as directed or intense as commercial fishing
33 Biomass and MSY estimation
Unexploited hiomass was calculated using a comparative approach based on data from 18 depletion surveys from similar regions in the South Pacific These surveys are outlined in Polovina and Shomura (1990) The estimated unexploited biomass (mtnmi) per unit area for seamount and insular areas was calculated (Table 3-3) usinghabitat estimates from the hydrographic surveys (Table 3-1) relative abundance estimates from the research fishing and the depletion survey information The results of applying 3 different fishery models (Beverton-Holt Gulland and Pauly) to data from the above regions in the South Pacific suggests the potential yield at MSY of stocks in the region is 10-30 of the unexploited biomass (Polovina and Shomura 1990)Based on these calculations the potential yield at MSY is 42-126 mt for seamounts in the Tuvaluan EEZ (Table 3-3) If atoll areas are included the MSY is estimated to be 64 to 192 mt
Using the range of landings from the research fishing (250-700 kgtrip) as a lowerbound of predicted commercial catch per trip the scale of the fishery can be estimated assuming 1 vessels catch = 1mt fishtrip 1 trip = 6 days fishing + 4 days in port for a total of 10 daystrip 1 vessel makes 3 tripsmonth the fishing season is 7 months Based on these assumptions 1 vessel could make 21 tripsseason By dividing the number of trips (lmttrip) into the MSY range (42-126 mt) it is estimated the seamount fishery could support 2 to 6 vessels If the 200m contour of the islands is included hypothetically the fishery could support 3 to 9 vessels (Alternatively if each vessel should catch 150 kg of bottomfish per fishing day for 90 fishing days per year then the mid-range estimate of the MSY on the seamounts could be caught byabout 6 vessels and the mid-range estimate of the MSY on both the seamounts and around the atolls could be caught with about 9 vessels) Care should be taken in applying an analysis of this type to the island contour as it assumes the bottomfishstocks are currently unexploited in those areas Furthermore the total allowable catch and thererore the number of fishing vessels will need to be restricted below the above estimates if financial considerations require the maintenance of high CPUEs
Finally it should be noted that the MSY estimates presented here are based on the results of research fishing trials and represent a preliminary estimate of yield after the commercial fishery reaches an equilibrium exploitation level As the commercial fisherydevelops catch and effort data should be collected to create a time series database which can be used to refine the MSY estimates
3-17 c
Table 3-2 Total catch by number and weight (marketable specieb only)
Species
A furcatus
A rutfans
A virescens
E carbunculus
E coruscans
E radiosus
P lausakari
P auricila
P filamentousus
P flavipinnus
P multidens
P zonatus
E areolatus
E chlorostigma
E fasciatus
E morrhua
Eseptemfasciatus
V out
V albomarginata
Other grouper
C ignobilis
C lugubris
S susmerili
S rivoliana
TOTAL
Weight(kq)
121
6352
1369
16827
9624
627
1336
1090
5200
3698
685
3366
160
519
20
3292
5389
263
150
356
452
13435
540
1640
76608
3-18
Percent of Total Weight ()
016
829
179
2196
1256
082
174
142
679
483
089
439
021
068
003
430
703
034
020
06
059
1754
070
214
10000
Table 3-3 Unexploited biomass and MSY range for Tuvalu
[Fishable Habitat Boo (mt) MSY Range(mt
Seamounts 421 42- 126
Islands 218 22 - 65
Total 639 64- 192
3-19
40 CONCLUSION
The hydrographic surveys on approximately 95 of Tuvalus fishable seamount and submerged bank habitat taken by the project staff on research and test fishing cruises show that Tuvalus distant seamounts have about 248 nautical miles of botomfish habitat as defined by the 200 m isobath or depth contour Together with the fishable habitat near the islands Tuvalu has a total 200 m depth contour of about 376 nautical miles The associated unexploited biomass of Tuvalus deep-water bottomfish on the distant seamounts is estimated at 421 mt while that for all of the Tuvalu EEZ is estimated at 639 mt The estimated MSY range for Tuvalus seamounts is 42-126 mtand the estimated MSY range for the entire Tuvalu EEZ is 64-192 mt Based on theseMSY estimates it has been calculated that this fishery could potentially support about 4 vessels fishing on the distant seamounts and about 2 additional vessels fishingaround Tuvalus islands
Contour maps of all of Tuvalus distant seamounts and 3-dimensional profiles of the smaller seamounts have been prepared and should prove useful to the Government of Tuvalu and to new entrants to the fishery
This final biological assessment by the Tuvalu Bottomfish Project concludes that Tuvalu does indeed have sufficient bottomfish habitat stock biomass and MSY to warrant the development of a modest commercial bottomfishing industry
4-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1
This report was made possible through support provided byUSAID under terms of Contract No AID-0020-C-O0- 1231shy00 The opinions expressed and conclusions reached here are those of the author and do not necessarily reflect the views of USAID
Hi
TABLE OF CONTENTS
Eage
10 EXECUTIVE SUMMARY1-1
20 INTRODUCTION 2-1
30 BIOLOGICAL ASSESSMENT 3-1 31 Hydrographic program 3-1 32 Research fishing 3-17 33 Biomass and MSY estimation 3-17
40 CONCLUSION 4-1
50 REFERENCES 5-1
iii
LIST OF TABLES
Page
Table 3-1 Length of 200 m isobath within the Tuvalu EEZ 3-3
Table 3-2 Total catch by number and weight (marketable species only) 3-18
Table 3-3 Unexploited biomass and MSY range for Tuvalu 3-19
LIST OF FIGURES
Page
Figure 2-1 Republic of Tuvalu EEZ 2-2
of Tuvalu
Figure 3-1 Survey areas of the islands banks and seamounts 3-2
Figure 3-2 Depth contour map of Luao Bank 3-4
Figure 3-3 3-dimensional profile of Luao Bank 3-5
Figure 3-4 Depth contour map of RDA Bank 3-6
Figure 3-5 3-dimensional profile of RDA Bank 3-7
Figure 3-6 Depth contour map of Talie Bank 3-8
Figure 3-7 3-dimensional profile of Talie Bank 3-9
Figure 3-8 Depth contour map of Hera Bank 3-10
Figure 3-10 Depth contour map of Takalo Bank 3-12
Figure 3-9 3-dimensional profile of Hera Bank 3-11
Figure 3-11 3-dimensional profile of Takalo Bank 3-13
Figure 3-12 Depth contour map of Kosciusco Area 3-14
Figure 3-13 Depth contour map of Bayonnaise Bank 3-15
Figure 3-14 Depth contour map of Macaw Bank Area 3-16
iv
ABBREv ATIONS
CPUE Catch per unit effort
EEZ Exclusive Economic Zone
FAD Fish aggregating device
GPS Geographical positioning system
GOT Government of Tuvalu
MRA Marine Resource Adviser
MSY Maximum sustainable yield
NAFICOT National Fishing Corporation of Tuvalu
NMI Nautical mile
PCC Project Coordination Committee
PIMAR Pacific Island Marine Resource
RDO Regional Development Office
SP South Pacific
USAID United States Agency for International Development
v
TUVALU BOTTOMFISH PROJECT FINAL BIOLOGICAL ASSESSMENT
10 EXECUTIVE SUMMARY
Twenty-nine iesearch cruises were completedduring the biological assessment phaseof the project using the Government of Tuvalu vessel the RV Manaui Thirteen different geographical areas were hydrographically surveyed and systematically fished Included in the areas surveyed were 2 previously unknown and uncharted seamountsRDA Bank and Takalo Bank which were located and hydrographically surveyed A total of 9981 kg of fish of 44 different species were caught during research fishingoperations Of this total 24 species were marketable with atotal weight of 7661 kgThree species Eteis carbunculus Etelis coruscans and Caranx lugubris made up the majority of catch by weight The average CPUE of all species was 555 kgline-hourand 405 kgline-hour for marketable species values similar to other regions in theSouth Pacific Based on hydrographic research survey results the total length of the 200 m contour (seamounts islands and banks) is estimated to be 376 nautical miles (nmi) within the Tuvalu EEZ (The area defined by the 200 m depth contour (isobath)has become a standard measure of bottomfish habitat useful in calculating the estimated biomass and fish stock and in comparing habitat size among various geographic areas throughout the South Pacific) The associated unexploited biomassof deep-water bottomfish is estimated to be 639 mt Estimated yield at MSY rangesfrom 64 to 192 mt Based on these MSY estimates it has been calculated that this fishery could potentially support about Avessels fishing on the distant seamounts and about 2 additional vessels fishing around Tuvalus islands
1-1
20 INTRODUCTION
The Republic of Tuvalu consists of nine emergent coral atolls and several submergedbanks lying between 4-140S latitude and 1720 E to 1760 VV longitude The Exclusive Economic Zone (EEZ) of the Republic of Tuvalu covers approximately 600000 km 2
(Figure 2-1) The Government of Tuvalu considers marine resources their mostimportant natural asset It realizes that while exploitation of deep-water bottomfish fishery resources could provide potential economic development tropical deep-waterbottomfish have a long life span slow growth rate and variable larval recruitmentwhich make these species highly susceptible to over-fishing Therefore to scale aviable long-term commercial fishery it is imperative that the sustainable yield of bottomfish stocks within the EEZ first be estimated Several approaches can be used to determine maximum sustainable yield (MSY) for an exploited commercial fisherydepending on the type quality and quantity of data available Most of theseapproaches depend on an extensive time series of catch-per-unit-effort (CPUE) data or a large sample of both CPUE and length data Unfortunately time and budgetconstraints precluded this type of research program and analysis for the Tuvaluan bottomfish stock However relative abundance and hydrographic data collected in this program allow the unexploited biomass within the EEZ to be estimated The range of MSY values can then be calculated for the unexploited stock
2-1
_ _
Figure 2-1 R
epublic of T
uvalu EEZ
tl
__ ___I _
_ _
_ I
---- _
S
- -
I i
_ _
_ _
2-2
0
30 BIOLOGICAL ASSESSMENT
31 Hydrographic program
Twenty-nine research cruises were completed during the assessment phase of theproject The Government of Tuvalu vessel the RV Manaui was used exclusively as the research platform Systematic surveys were conducted throughout the archipelago(Figure 3-1) to provide information on local bathymetry species composition lengthfrequency catch rates and depth distributions
One hundred one (101) data sets were compiled from the data collected during the biological assessment phase of the project The data were entered into database software in Tuvalu These data were subsequently sent to the RDA Marine Biologistfor analysis Statistical analyses were done using the SAS statistical packageHydrographic data were analyzed and plotted using a commercial digitizing templateand Quattro Pro and SURFER hydrographic plotting software
Hydrographic measurements were taken using a GPS positioning unit and a color sounding chromoscope From this data hydrographic chartlets of areas of potentialfishery habitat were produced and plotted Approximately 95 of fishable seamount and submerged bank habitat in the Tuvaluan Archipelago was surveyed byhydrographic measurements and research fishing During the course of fishing andhydrographic operations five small seamounts were located and charted (Figures 3-2 through 3-11) In addition the poorly charted submerged bank areas in the south ofthe archipelago (Kosciusco Bank Bayonnaise Bank and Macaw Bank areas) wereextensively surveyed (Figures 3-12 3-13 and 3-14) The hydrographic data were digitized using the electronic template to calculate the length of the 200 m contour foreach seamount or bank system Potential fishery habitat expressed as the length of the 200 m contour is given in Table 3-1
3-1
Figure 3-1 S
urvey areas of the islands banks and seam
ounts of Tuvalu
-CD
I 0
2
1r4pj
_ _
_ shy
oc
(S) epnjpe shy
Arrow
s denote survey areas
3-2
Table 3-1 Length of 200m isobath within the Tuvalu EEZ
Bank
Luao
Kosciusko-Martha-Niulakita
Macaw
RDA
Talie
Bayonnaise
Hera
Takalo
Roseb
Total (seamounts)
Total (islands)
Total (Tuvalu)
Isobath Length (nautical miles)
672
8047
2479
175
323
9562
965
1212
1331
24766
12820C
37586
The large seamount surface extending from Niulakita was included in the 200 m isobath measurement for Kosciusko Martha Bank was also included with the Kosciusko Bank b The isobath length for Rose Bank is presented here separately but it is sufficiently indistinguishable from Kosciusko Bank that it could as well have been included along with Martha Bank with the isobath length for Kosciusko Bank
C Reference Dalzell and Preston 1991
3-3
Figure 3-2 Depth contour map of Luao Bank
10 153
-10157
-10161
-l0165
-10169
-10173
-10177
j_
f_
L_
LUAO BANK
=shy
-_
_
Q
_
-10181 T
-10197 ---- - -0 F -10201
-179708 -179703 -179698 -179693
I oncitude (W) -179688
3-4 12
Figure 3-3 3-dimensional profile of Luao Bank
LUAO SANK
3-5 1
C
Figure 3-4 D
epth contour map o
f RD
A B
ank
I1A
-
_
_ __
7
-17 k
V___ I
C
4J
In
D 0
I
I
b
d
N
I
I
ii p
Nr-
IN
I
N
I
0
3-6
Figure 3-5 3-dim
ensional profile of R
DA
B
ank
w
z z lt
S-
let-
ci-d
ti-IC
O-
Z-
-ee-
ZS
-E
G-
60C-
5C
fshy
3-7
Figure 3-6 Depth contour map of Talie Bank
-6226
TALIE BANK
-6229 - - - -I -
-62 3 1
-( -6234 -7
i
-shy_
7 (NT--- -shy
_
-6237
-6240
S-6243
-62436-
_
I
-
- -
t
- -
- -
~ ~1~-
I
PI
--1 - - - -
shy
-I- - - -
-6249
176324 1763327 176330 1763-3 176336
Longitude 176339
(E) 176342 176345 1763
3-8
Figure 3-7 3-dimensional profile of Talie Bank
TeI Le Ben k
3-9
Figure 3-8 Depth contour map of Hera Bank
HERA BANK
-1215
0 -12160
Q
j 12169 - -
- 12 18 5 -179251 -179242 -179233 -179224 -1792 14
I r -179205 -179196
Longitude (W)
3-10
Figure 3-9 3-dimensional profile of Hera Bank
Hera Benk
3-11
Figure 3-10 Depth contour map of Takalo Bank
TAKALO BANK -1144
-1145 shy
-114
-114 0_49
- 115o0shy
-1151
-17961 -17960 -17959 -17958 -17957 -17956 -17955
Longitude (W)
3-12
Figure 3-1 1 3-dimensional profile of Takalo Bank
TekaIo Benk
C
Ic2
3-13
-1038
Figure 3-12 Depth contour map of Kosciusco Bank Area
KOSCIUSKO AREA
1042 + -1
-1046 -0
-1058-1054 -0 Cgt1 (j70
ci)i
-1067
-1071 L _ _j
- 1075 -- 1--
-1083 C __I
- 1087 fill 1 f
17937 17941 17945 17949 17953 17957 17961 17965 17969
Longitude (E) 3-14
-------
-----
Figure 3-13 Depth contour map of Bayonnaise Bank
BAYONNAISE BANK
-1158 ----- 190 -I I
I I
- --------- I
-1158 L ----- L-----GI
I -1108 ---- L- I -I I I
I I
K)I I
(f)-1188 K
-31198 -121 --------L--------L-------------shy
-J 0 K -1178 --- -- L ------- L----- -
1208------LI~p
00
-1218-- ------ L L __
II I I I I I I I
I-1228---------- -I
- L-- - 7 --- L II I II
I I
I I
-1238 -17989 -17979 -17969 -17959 -17949 -17939
Longitude (W)
3-15
Figure 3-14 Depth contour map of Macaw Bank Area
v-CAW BANK AREA
1060I -- I - L -I
I II
I I I-1060-----------shy
k I I II
oI
-o~1 - - - L
II
-1066ii~I amp )
-1065---- -
I I
-1067
I I I
-1069 -17926 -17925 -17924- - 7923 -17922 -17921 -17920 -17919 -17918
Longitude (W)
3-16
32 Research fishing
A total of 9981 kg of fish of 44 different species were caught Of this total 24 species were marketable with a total weight of 7661 kg (77) (Table 3-2) Three species Etelis carbunculus Etelis coruscans and Caranx lugubris made up the majorityof catch by weight The average CPUE of all species was 555 kgline-hour and 405 kgline-hour for marketable species These CPUE values are average by regionalstandards and probably represent the lower bound of a commercial CPUE range This is because research fishing is usually not as directed or intense as commercial fishing
33 Biomass and MSY estimation
Unexploited hiomass was calculated using a comparative approach based on data from 18 depletion surveys from similar regions in the South Pacific These surveys are outlined in Polovina and Shomura (1990) The estimated unexploited biomass (mtnmi) per unit area for seamount and insular areas was calculated (Table 3-3) usinghabitat estimates from the hydrographic surveys (Table 3-1) relative abundance estimates from the research fishing and the depletion survey information The results of applying 3 different fishery models (Beverton-Holt Gulland and Pauly) to data from the above regions in the South Pacific suggests the potential yield at MSY of stocks in the region is 10-30 of the unexploited biomass (Polovina and Shomura 1990)Based on these calculations the potential yield at MSY is 42-126 mt for seamounts in the Tuvaluan EEZ (Table 3-3) If atoll areas are included the MSY is estimated to be 64 to 192 mt
Using the range of landings from the research fishing (250-700 kgtrip) as a lowerbound of predicted commercial catch per trip the scale of the fishery can be estimated assuming 1 vessels catch = 1mt fishtrip 1 trip = 6 days fishing + 4 days in port for a total of 10 daystrip 1 vessel makes 3 tripsmonth the fishing season is 7 months Based on these assumptions 1 vessel could make 21 tripsseason By dividing the number of trips (lmttrip) into the MSY range (42-126 mt) it is estimated the seamount fishery could support 2 to 6 vessels If the 200m contour of the islands is included hypothetically the fishery could support 3 to 9 vessels (Alternatively if each vessel should catch 150 kg of bottomfish per fishing day for 90 fishing days per year then the mid-range estimate of the MSY on the seamounts could be caught byabout 6 vessels and the mid-range estimate of the MSY on both the seamounts and around the atolls could be caught with about 9 vessels) Care should be taken in applying an analysis of this type to the island contour as it assumes the bottomfishstocks are currently unexploited in those areas Furthermore the total allowable catch and thererore the number of fishing vessels will need to be restricted below the above estimates if financial considerations require the maintenance of high CPUEs
Finally it should be noted that the MSY estimates presented here are based on the results of research fishing trials and represent a preliminary estimate of yield after the commercial fishery reaches an equilibrium exploitation level As the commercial fisherydevelops catch and effort data should be collected to create a time series database which can be used to refine the MSY estimates
3-17 c
Table 3-2 Total catch by number and weight (marketable specieb only)
Species
A furcatus
A rutfans
A virescens
E carbunculus
E coruscans
E radiosus
P lausakari
P auricila
P filamentousus
P flavipinnus
P multidens
P zonatus
E areolatus
E chlorostigma
E fasciatus
E morrhua
Eseptemfasciatus
V out
V albomarginata
Other grouper
C ignobilis
C lugubris
S susmerili
S rivoliana
TOTAL
Weight(kq)
121
6352
1369
16827
9624
627
1336
1090
5200
3698
685
3366
160
519
20
3292
5389
263
150
356
452
13435
540
1640
76608
3-18
Percent of Total Weight ()
016
829
179
2196
1256
082
174
142
679
483
089
439
021
068
003
430
703
034
020
06
059
1754
070
214
10000
Table 3-3 Unexploited biomass and MSY range for Tuvalu
[Fishable Habitat Boo (mt) MSY Range(mt
Seamounts 421 42- 126
Islands 218 22 - 65
Total 639 64- 192
3-19
40 CONCLUSION
The hydrographic surveys on approximately 95 of Tuvalus fishable seamount and submerged bank habitat taken by the project staff on research and test fishing cruises show that Tuvalus distant seamounts have about 248 nautical miles of botomfish habitat as defined by the 200 m isobath or depth contour Together with the fishable habitat near the islands Tuvalu has a total 200 m depth contour of about 376 nautical miles The associated unexploited biomass of Tuvalus deep-water bottomfish on the distant seamounts is estimated at 421 mt while that for all of the Tuvalu EEZ is estimated at 639 mt The estimated MSY range for Tuvalus seamounts is 42-126 mtand the estimated MSY range for the entire Tuvalu EEZ is 64-192 mt Based on theseMSY estimates it has been calculated that this fishery could potentially support about 4 vessels fishing on the distant seamounts and about 2 additional vessels fishingaround Tuvalus islands
Contour maps of all of Tuvalus distant seamounts and 3-dimensional profiles of the smaller seamounts have been prepared and should prove useful to the Government of Tuvalu and to new entrants to the fishery
This final biological assessment by the Tuvalu Bottomfish Project concludes that Tuvalu does indeed have sufficient bottomfish habitat stock biomass and MSY to warrant the development of a modest commercial bottomfishing industry
4-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1
TABLE OF CONTENTS
Eage
10 EXECUTIVE SUMMARY1-1
20 INTRODUCTION 2-1
30 BIOLOGICAL ASSESSMENT 3-1 31 Hydrographic program 3-1 32 Research fishing 3-17 33 Biomass and MSY estimation 3-17
40 CONCLUSION 4-1
50 REFERENCES 5-1
iii
LIST OF TABLES
Page
Table 3-1 Length of 200 m isobath within the Tuvalu EEZ 3-3
Table 3-2 Total catch by number and weight (marketable species only) 3-18
Table 3-3 Unexploited biomass and MSY range for Tuvalu 3-19
LIST OF FIGURES
Page
Figure 2-1 Republic of Tuvalu EEZ 2-2
of Tuvalu
Figure 3-1 Survey areas of the islands banks and seamounts 3-2
Figure 3-2 Depth contour map of Luao Bank 3-4
Figure 3-3 3-dimensional profile of Luao Bank 3-5
Figure 3-4 Depth contour map of RDA Bank 3-6
Figure 3-5 3-dimensional profile of RDA Bank 3-7
Figure 3-6 Depth contour map of Talie Bank 3-8
Figure 3-7 3-dimensional profile of Talie Bank 3-9
Figure 3-8 Depth contour map of Hera Bank 3-10
Figure 3-10 Depth contour map of Takalo Bank 3-12
Figure 3-9 3-dimensional profile of Hera Bank 3-11
Figure 3-11 3-dimensional profile of Takalo Bank 3-13
Figure 3-12 Depth contour map of Kosciusco Area 3-14
Figure 3-13 Depth contour map of Bayonnaise Bank 3-15
Figure 3-14 Depth contour map of Macaw Bank Area 3-16
iv
ABBREv ATIONS
CPUE Catch per unit effort
EEZ Exclusive Economic Zone
FAD Fish aggregating device
GPS Geographical positioning system
GOT Government of Tuvalu
MRA Marine Resource Adviser
MSY Maximum sustainable yield
NAFICOT National Fishing Corporation of Tuvalu
NMI Nautical mile
PCC Project Coordination Committee
PIMAR Pacific Island Marine Resource
RDO Regional Development Office
SP South Pacific
USAID United States Agency for International Development
v
TUVALU BOTTOMFISH PROJECT FINAL BIOLOGICAL ASSESSMENT
10 EXECUTIVE SUMMARY
Twenty-nine iesearch cruises were completedduring the biological assessment phaseof the project using the Government of Tuvalu vessel the RV Manaui Thirteen different geographical areas were hydrographically surveyed and systematically fished Included in the areas surveyed were 2 previously unknown and uncharted seamountsRDA Bank and Takalo Bank which were located and hydrographically surveyed A total of 9981 kg of fish of 44 different species were caught during research fishingoperations Of this total 24 species were marketable with atotal weight of 7661 kgThree species Eteis carbunculus Etelis coruscans and Caranx lugubris made up the majority of catch by weight The average CPUE of all species was 555 kgline-hourand 405 kgline-hour for marketable species values similar to other regions in theSouth Pacific Based on hydrographic research survey results the total length of the 200 m contour (seamounts islands and banks) is estimated to be 376 nautical miles (nmi) within the Tuvalu EEZ (The area defined by the 200 m depth contour (isobath)has become a standard measure of bottomfish habitat useful in calculating the estimated biomass and fish stock and in comparing habitat size among various geographic areas throughout the South Pacific) The associated unexploited biomassof deep-water bottomfish is estimated to be 639 mt Estimated yield at MSY rangesfrom 64 to 192 mt Based on these MSY estimates it has been calculated that this fishery could potentially support about Avessels fishing on the distant seamounts and about 2 additional vessels fishing around Tuvalus islands
1-1
20 INTRODUCTION
The Republic of Tuvalu consists of nine emergent coral atolls and several submergedbanks lying between 4-140S latitude and 1720 E to 1760 VV longitude The Exclusive Economic Zone (EEZ) of the Republic of Tuvalu covers approximately 600000 km 2
(Figure 2-1) The Government of Tuvalu considers marine resources their mostimportant natural asset It realizes that while exploitation of deep-water bottomfish fishery resources could provide potential economic development tropical deep-waterbottomfish have a long life span slow growth rate and variable larval recruitmentwhich make these species highly susceptible to over-fishing Therefore to scale aviable long-term commercial fishery it is imperative that the sustainable yield of bottomfish stocks within the EEZ first be estimated Several approaches can be used to determine maximum sustainable yield (MSY) for an exploited commercial fisherydepending on the type quality and quantity of data available Most of theseapproaches depend on an extensive time series of catch-per-unit-effort (CPUE) data or a large sample of both CPUE and length data Unfortunately time and budgetconstraints precluded this type of research program and analysis for the Tuvaluan bottomfish stock However relative abundance and hydrographic data collected in this program allow the unexploited biomass within the EEZ to be estimated The range of MSY values can then be calculated for the unexploited stock
2-1
_ _
Figure 2-1 R
epublic of T
uvalu EEZ
tl
__ ___I _
_ _
_ I
---- _
S
- -
I i
_ _
_ _
2-2
0
30 BIOLOGICAL ASSESSMENT
31 Hydrographic program
Twenty-nine research cruises were completed during the assessment phase of theproject The Government of Tuvalu vessel the RV Manaui was used exclusively as the research platform Systematic surveys were conducted throughout the archipelago(Figure 3-1) to provide information on local bathymetry species composition lengthfrequency catch rates and depth distributions
One hundred one (101) data sets were compiled from the data collected during the biological assessment phase of the project The data were entered into database software in Tuvalu These data were subsequently sent to the RDA Marine Biologistfor analysis Statistical analyses were done using the SAS statistical packageHydrographic data were analyzed and plotted using a commercial digitizing templateand Quattro Pro and SURFER hydrographic plotting software
Hydrographic measurements were taken using a GPS positioning unit and a color sounding chromoscope From this data hydrographic chartlets of areas of potentialfishery habitat were produced and plotted Approximately 95 of fishable seamount and submerged bank habitat in the Tuvaluan Archipelago was surveyed byhydrographic measurements and research fishing During the course of fishing andhydrographic operations five small seamounts were located and charted (Figures 3-2 through 3-11) In addition the poorly charted submerged bank areas in the south ofthe archipelago (Kosciusco Bank Bayonnaise Bank and Macaw Bank areas) wereextensively surveyed (Figures 3-12 3-13 and 3-14) The hydrographic data were digitized using the electronic template to calculate the length of the 200 m contour foreach seamount or bank system Potential fishery habitat expressed as the length of the 200 m contour is given in Table 3-1
3-1
Figure 3-1 S
urvey areas of the islands banks and seam
ounts of Tuvalu
-CD
I 0
2
1r4pj
_ _
_ shy
oc
(S) epnjpe shy
Arrow
s denote survey areas
3-2
Table 3-1 Length of 200m isobath within the Tuvalu EEZ
Bank
Luao
Kosciusko-Martha-Niulakita
Macaw
RDA
Talie
Bayonnaise
Hera
Takalo
Roseb
Total (seamounts)
Total (islands)
Total (Tuvalu)
Isobath Length (nautical miles)
672
8047
2479
175
323
9562
965
1212
1331
24766
12820C
37586
The large seamount surface extending from Niulakita was included in the 200 m isobath measurement for Kosciusko Martha Bank was also included with the Kosciusko Bank b The isobath length for Rose Bank is presented here separately but it is sufficiently indistinguishable from Kosciusko Bank that it could as well have been included along with Martha Bank with the isobath length for Kosciusko Bank
C Reference Dalzell and Preston 1991
3-3
Figure 3-2 Depth contour map of Luao Bank
10 153
-10157
-10161
-l0165
-10169
-10173
-10177
j_
f_
L_
LUAO BANK
=shy
-_
_
Q
_
-10181 T
-10197 ---- - -0 F -10201
-179708 -179703 -179698 -179693
I oncitude (W) -179688
3-4 12
Figure 3-3 3-dimensional profile of Luao Bank
LUAO SANK
3-5 1
C
Figure 3-4 D
epth contour map o
f RD
A B
ank
I1A
-
_
_ __
7
-17 k
V___ I
C
4J
In
D 0
I
I
b
d
N
I
I
ii p
Nr-
IN
I
N
I
0
3-6
Figure 3-5 3-dim
ensional profile of R
DA
B
ank
w
z z lt
S-
let-
ci-d
ti-IC
O-
Z-
-ee-
ZS
-E
G-
60C-
5C
fshy
3-7
Figure 3-6 Depth contour map of Talie Bank
-6226
TALIE BANK
-6229 - - - -I -
-62 3 1
-( -6234 -7
i
-shy_
7 (NT--- -shy
_
-6237
-6240
S-6243
-62436-
_
I
-
- -
t
- -
- -
~ ~1~-
I
PI
--1 - - - -
shy
-I- - - -
-6249
176324 1763327 176330 1763-3 176336
Longitude 176339
(E) 176342 176345 1763
3-8
Figure 3-7 3-dimensional profile of Talie Bank
TeI Le Ben k
3-9
Figure 3-8 Depth contour map of Hera Bank
HERA BANK
-1215
0 -12160
Q
j 12169 - -
- 12 18 5 -179251 -179242 -179233 -179224 -1792 14
I r -179205 -179196
Longitude (W)
3-10
Figure 3-9 3-dimensional profile of Hera Bank
Hera Benk
3-11
Figure 3-10 Depth contour map of Takalo Bank
TAKALO BANK -1144
-1145 shy
-114
-114 0_49
- 115o0shy
-1151
-17961 -17960 -17959 -17958 -17957 -17956 -17955
Longitude (W)
3-12
Figure 3-1 1 3-dimensional profile of Takalo Bank
TekaIo Benk
C
Ic2
3-13
-1038
Figure 3-12 Depth contour map of Kosciusco Bank Area
KOSCIUSKO AREA
1042 + -1
-1046 -0
-1058-1054 -0 Cgt1 (j70
ci)i
-1067
-1071 L _ _j
- 1075 -- 1--
-1083 C __I
- 1087 fill 1 f
17937 17941 17945 17949 17953 17957 17961 17965 17969
Longitude (E) 3-14
-------
-----
Figure 3-13 Depth contour map of Bayonnaise Bank
BAYONNAISE BANK
-1158 ----- 190 -I I
I I
- --------- I
-1158 L ----- L-----GI
I -1108 ---- L- I -I I I
I I
K)I I
(f)-1188 K
-31198 -121 --------L--------L-------------shy
-J 0 K -1178 --- -- L ------- L----- -
1208------LI~p
00
-1218-- ------ L L __
II I I I I I I I
I-1228---------- -I
- L-- - 7 --- L II I II
I I
I I
-1238 -17989 -17979 -17969 -17959 -17949 -17939
Longitude (W)
3-15
Figure 3-14 Depth contour map of Macaw Bank Area
v-CAW BANK AREA
1060I -- I - L -I
I II
I I I-1060-----------shy
k I I II
oI
-o~1 - - - L
II
-1066ii~I amp )
-1065---- -
I I
-1067
I I I
-1069 -17926 -17925 -17924- - 7923 -17922 -17921 -17920 -17919 -17918
Longitude (W)
3-16
32 Research fishing
A total of 9981 kg of fish of 44 different species were caught Of this total 24 species were marketable with a total weight of 7661 kg (77) (Table 3-2) Three species Etelis carbunculus Etelis coruscans and Caranx lugubris made up the majorityof catch by weight The average CPUE of all species was 555 kgline-hour and 405 kgline-hour for marketable species These CPUE values are average by regionalstandards and probably represent the lower bound of a commercial CPUE range This is because research fishing is usually not as directed or intense as commercial fishing
33 Biomass and MSY estimation
Unexploited hiomass was calculated using a comparative approach based on data from 18 depletion surveys from similar regions in the South Pacific These surveys are outlined in Polovina and Shomura (1990) The estimated unexploited biomass (mtnmi) per unit area for seamount and insular areas was calculated (Table 3-3) usinghabitat estimates from the hydrographic surveys (Table 3-1) relative abundance estimates from the research fishing and the depletion survey information The results of applying 3 different fishery models (Beverton-Holt Gulland and Pauly) to data from the above regions in the South Pacific suggests the potential yield at MSY of stocks in the region is 10-30 of the unexploited biomass (Polovina and Shomura 1990)Based on these calculations the potential yield at MSY is 42-126 mt for seamounts in the Tuvaluan EEZ (Table 3-3) If atoll areas are included the MSY is estimated to be 64 to 192 mt
Using the range of landings from the research fishing (250-700 kgtrip) as a lowerbound of predicted commercial catch per trip the scale of the fishery can be estimated assuming 1 vessels catch = 1mt fishtrip 1 trip = 6 days fishing + 4 days in port for a total of 10 daystrip 1 vessel makes 3 tripsmonth the fishing season is 7 months Based on these assumptions 1 vessel could make 21 tripsseason By dividing the number of trips (lmttrip) into the MSY range (42-126 mt) it is estimated the seamount fishery could support 2 to 6 vessels If the 200m contour of the islands is included hypothetically the fishery could support 3 to 9 vessels (Alternatively if each vessel should catch 150 kg of bottomfish per fishing day for 90 fishing days per year then the mid-range estimate of the MSY on the seamounts could be caught byabout 6 vessels and the mid-range estimate of the MSY on both the seamounts and around the atolls could be caught with about 9 vessels) Care should be taken in applying an analysis of this type to the island contour as it assumes the bottomfishstocks are currently unexploited in those areas Furthermore the total allowable catch and thererore the number of fishing vessels will need to be restricted below the above estimates if financial considerations require the maintenance of high CPUEs
Finally it should be noted that the MSY estimates presented here are based on the results of research fishing trials and represent a preliminary estimate of yield after the commercial fishery reaches an equilibrium exploitation level As the commercial fisherydevelops catch and effort data should be collected to create a time series database which can be used to refine the MSY estimates
3-17 c
Table 3-2 Total catch by number and weight (marketable specieb only)
Species
A furcatus
A rutfans
A virescens
E carbunculus
E coruscans
E radiosus
P lausakari
P auricila
P filamentousus
P flavipinnus
P multidens
P zonatus
E areolatus
E chlorostigma
E fasciatus
E morrhua
Eseptemfasciatus
V out
V albomarginata
Other grouper
C ignobilis
C lugubris
S susmerili
S rivoliana
TOTAL
Weight(kq)
121
6352
1369
16827
9624
627
1336
1090
5200
3698
685
3366
160
519
20
3292
5389
263
150
356
452
13435
540
1640
76608
3-18
Percent of Total Weight ()
016
829
179
2196
1256
082
174
142
679
483
089
439
021
068
003
430
703
034
020
06
059
1754
070
214
10000
Table 3-3 Unexploited biomass and MSY range for Tuvalu
[Fishable Habitat Boo (mt) MSY Range(mt
Seamounts 421 42- 126
Islands 218 22 - 65
Total 639 64- 192
3-19
40 CONCLUSION
The hydrographic surveys on approximately 95 of Tuvalus fishable seamount and submerged bank habitat taken by the project staff on research and test fishing cruises show that Tuvalus distant seamounts have about 248 nautical miles of botomfish habitat as defined by the 200 m isobath or depth contour Together with the fishable habitat near the islands Tuvalu has a total 200 m depth contour of about 376 nautical miles The associated unexploited biomass of Tuvalus deep-water bottomfish on the distant seamounts is estimated at 421 mt while that for all of the Tuvalu EEZ is estimated at 639 mt The estimated MSY range for Tuvalus seamounts is 42-126 mtand the estimated MSY range for the entire Tuvalu EEZ is 64-192 mt Based on theseMSY estimates it has been calculated that this fishery could potentially support about 4 vessels fishing on the distant seamounts and about 2 additional vessels fishingaround Tuvalus islands
Contour maps of all of Tuvalus distant seamounts and 3-dimensional profiles of the smaller seamounts have been prepared and should prove useful to the Government of Tuvalu and to new entrants to the fishery
This final biological assessment by the Tuvalu Bottomfish Project concludes that Tuvalu does indeed have sufficient bottomfish habitat stock biomass and MSY to warrant the development of a modest commercial bottomfishing industry
4-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1
LIST OF TABLES
Page
Table 3-1 Length of 200 m isobath within the Tuvalu EEZ 3-3
Table 3-2 Total catch by number and weight (marketable species only) 3-18
Table 3-3 Unexploited biomass and MSY range for Tuvalu 3-19
LIST OF FIGURES
Page
Figure 2-1 Republic of Tuvalu EEZ 2-2
of Tuvalu
Figure 3-1 Survey areas of the islands banks and seamounts 3-2
Figure 3-2 Depth contour map of Luao Bank 3-4
Figure 3-3 3-dimensional profile of Luao Bank 3-5
Figure 3-4 Depth contour map of RDA Bank 3-6
Figure 3-5 3-dimensional profile of RDA Bank 3-7
Figure 3-6 Depth contour map of Talie Bank 3-8
Figure 3-7 3-dimensional profile of Talie Bank 3-9
Figure 3-8 Depth contour map of Hera Bank 3-10
Figure 3-10 Depth contour map of Takalo Bank 3-12
Figure 3-9 3-dimensional profile of Hera Bank 3-11
Figure 3-11 3-dimensional profile of Takalo Bank 3-13
Figure 3-12 Depth contour map of Kosciusco Area 3-14
Figure 3-13 Depth contour map of Bayonnaise Bank 3-15
Figure 3-14 Depth contour map of Macaw Bank Area 3-16
iv
ABBREv ATIONS
CPUE Catch per unit effort
EEZ Exclusive Economic Zone
FAD Fish aggregating device
GPS Geographical positioning system
GOT Government of Tuvalu
MRA Marine Resource Adviser
MSY Maximum sustainable yield
NAFICOT National Fishing Corporation of Tuvalu
NMI Nautical mile
PCC Project Coordination Committee
PIMAR Pacific Island Marine Resource
RDO Regional Development Office
SP South Pacific
USAID United States Agency for International Development
v
TUVALU BOTTOMFISH PROJECT FINAL BIOLOGICAL ASSESSMENT
10 EXECUTIVE SUMMARY
Twenty-nine iesearch cruises were completedduring the biological assessment phaseof the project using the Government of Tuvalu vessel the RV Manaui Thirteen different geographical areas were hydrographically surveyed and systematically fished Included in the areas surveyed were 2 previously unknown and uncharted seamountsRDA Bank and Takalo Bank which were located and hydrographically surveyed A total of 9981 kg of fish of 44 different species were caught during research fishingoperations Of this total 24 species were marketable with atotal weight of 7661 kgThree species Eteis carbunculus Etelis coruscans and Caranx lugubris made up the majority of catch by weight The average CPUE of all species was 555 kgline-hourand 405 kgline-hour for marketable species values similar to other regions in theSouth Pacific Based on hydrographic research survey results the total length of the 200 m contour (seamounts islands and banks) is estimated to be 376 nautical miles (nmi) within the Tuvalu EEZ (The area defined by the 200 m depth contour (isobath)has become a standard measure of bottomfish habitat useful in calculating the estimated biomass and fish stock and in comparing habitat size among various geographic areas throughout the South Pacific) The associated unexploited biomassof deep-water bottomfish is estimated to be 639 mt Estimated yield at MSY rangesfrom 64 to 192 mt Based on these MSY estimates it has been calculated that this fishery could potentially support about Avessels fishing on the distant seamounts and about 2 additional vessels fishing around Tuvalus islands
1-1
20 INTRODUCTION
The Republic of Tuvalu consists of nine emergent coral atolls and several submergedbanks lying between 4-140S latitude and 1720 E to 1760 VV longitude The Exclusive Economic Zone (EEZ) of the Republic of Tuvalu covers approximately 600000 km 2
(Figure 2-1) The Government of Tuvalu considers marine resources their mostimportant natural asset It realizes that while exploitation of deep-water bottomfish fishery resources could provide potential economic development tropical deep-waterbottomfish have a long life span slow growth rate and variable larval recruitmentwhich make these species highly susceptible to over-fishing Therefore to scale aviable long-term commercial fishery it is imperative that the sustainable yield of bottomfish stocks within the EEZ first be estimated Several approaches can be used to determine maximum sustainable yield (MSY) for an exploited commercial fisherydepending on the type quality and quantity of data available Most of theseapproaches depend on an extensive time series of catch-per-unit-effort (CPUE) data or a large sample of both CPUE and length data Unfortunately time and budgetconstraints precluded this type of research program and analysis for the Tuvaluan bottomfish stock However relative abundance and hydrographic data collected in this program allow the unexploited biomass within the EEZ to be estimated The range of MSY values can then be calculated for the unexploited stock
2-1
_ _
Figure 2-1 R
epublic of T
uvalu EEZ
tl
__ ___I _
_ _
_ I
---- _
S
- -
I i
_ _
_ _
2-2
0
30 BIOLOGICAL ASSESSMENT
31 Hydrographic program
Twenty-nine research cruises were completed during the assessment phase of theproject The Government of Tuvalu vessel the RV Manaui was used exclusively as the research platform Systematic surveys were conducted throughout the archipelago(Figure 3-1) to provide information on local bathymetry species composition lengthfrequency catch rates and depth distributions
One hundred one (101) data sets were compiled from the data collected during the biological assessment phase of the project The data were entered into database software in Tuvalu These data were subsequently sent to the RDA Marine Biologistfor analysis Statistical analyses were done using the SAS statistical packageHydrographic data were analyzed and plotted using a commercial digitizing templateand Quattro Pro and SURFER hydrographic plotting software
Hydrographic measurements were taken using a GPS positioning unit and a color sounding chromoscope From this data hydrographic chartlets of areas of potentialfishery habitat were produced and plotted Approximately 95 of fishable seamount and submerged bank habitat in the Tuvaluan Archipelago was surveyed byhydrographic measurements and research fishing During the course of fishing andhydrographic operations five small seamounts were located and charted (Figures 3-2 through 3-11) In addition the poorly charted submerged bank areas in the south ofthe archipelago (Kosciusco Bank Bayonnaise Bank and Macaw Bank areas) wereextensively surveyed (Figures 3-12 3-13 and 3-14) The hydrographic data were digitized using the electronic template to calculate the length of the 200 m contour foreach seamount or bank system Potential fishery habitat expressed as the length of the 200 m contour is given in Table 3-1
3-1
Figure 3-1 S
urvey areas of the islands banks and seam
ounts of Tuvalu
-CD
I 0
2
1r4pj
_ _
_ shy
oc
(S) epnjpe shy
Arrow
s denote survey areas
3-2
Table 3-1 Length of 200m isobath within the Tuvalu EEZ
Bank
Luao
Kosciusko-Martha-Niulakita
Macaw
RDA
Talie
Bayonnaise
Hera
Takalo
Roseb
Total (seamounts)
Total (islands)
Total (Tuvalu)
Isobath Length (nautical miles)
672
8047
2479
175
323
9562
965
1212
1331
24766
12820C
37586
The large seamount surface extending from Niulakita was included in the 200 m isobath measurement for Kosciusko Martha Bank was also included with the Kosciusko Bank b The isobath length for Rose Bank is presented here separately but it is sufficiently indistinguishable from Kosciusko Bank that it could as well have been included along with Martha Bank with the isobath length for Kosciusko Bank
C Reference Dalzell and Preston 1991
3-3
Figure 3-2 Depth contour map of Luao Bank
10 153
-10157
-10161
-l0165
-10169
-10173
-10177
j_
f_
L_
LUAO BANK
=shy
-_
_
Q
_
-10181 T
-10197 ---- - -0 F -10201
-179708 -179703 -179698 -179693
I oncitude (W) -179688
3-4 12
Figure 3-3 3-dimensional profile of Luao Bank
LUAO SANK
3-5 1
C
Figure 3-4 D
epth contour map o
f RD
A B
ank
I1A
-
_
_ __
7
-17 k
V___ I
C
4J
In
D 0
I
I
b
d
N
I
I
ii p
Nr-
IN
I
N
I
0
3-6
Figure 3-5 3-dim
ensional profile of R
DA
B
ank
w
z z lt
S-
let-
ci-d
ti-IC
O-
Z-
-ee-
ZS
-E
G-
60C-
5C
fshy
3-7
Figure 3-6 Depth contour map of Talie Bank
-6226
TALIE BANK
-6229 - - - -I -
-62 3 1
-( -6234 -7
i
-shy_
7 (NT--- -shy
_
-6237
-6240
S-6243
-62436-
_
I
-
- -
t
- -
- -
~ ~1~-
I
PI
--1 - - - -
shy
-I- - - -
-6249
176324 1763327 176330 1763-3 176336
Longitude 176339
(E) 176342 176345 1763
3-8
Figure 3-7 3-dimensional profile of Talie Bank
TeI Le Ben k
3-9
Figure 3-8 Depth contour map of Hera Bank
HERA BANK
-1215
0 -12160
Q
j 12169 - -
- 12 18 5 -179251 -179242 -179233 -179224 -1792 14
I r -179205 -179196
Longitude (W)
3-10
Figure 3-9 3-dimensional profile of Hera Bank
Hera Benk
3-11
Figure 3-10 Depth contour map of Takalo Bank
TAKALO BANK -1144
-1145 shy
-114
-114 0_49
- 115o0shy
-1151
-17961 -17960 -17959 -17958 -17957 -17956 -17955
Longitude (W)
3-12
Figure 3-1 1 3-dimensional profile of Takalo Bank
TekaIo Benk
C
Ic2
3-13
-1038
Figure 3-12 Depth contour map of Kosciusco Bank Area
KOSCIUSKO AREA
1042 + -1
-1046 -0
-1058-1054 -0 Cgt1 (j70
ci)i
-1067
-1071 L _ _j
- 1075 -- 1--
-1083 C __I
- 1087 fill 1 f
17937 17941 17945 17949 17953 17957 17961 17965 17969
Longitude (E) 3-14
-------
-----
Figure 3-13 Depth contour map of Bayonnaise Bank
BAYONNAISE BANK
-1158 ----- 190 -I I
I I
- --------- I
-1158 L ----- L-----GI
I -1108 ---- L- I -I I I
I I
K)I I
(f)-1188 K
-31198 -121 --------L--------L-------------shy
-J 0 K -1178 --- -- L ------- L----- -
1208------LI~p
00
-1218-- ------ L L __
II I I I I I I I
I-1228---------- -I
- L-- - 7 --- L II I II
I I
I I
-1238 -17989 -17979 -17969 -17959 -17949 -17939
Longitude (W)
3-15
Figure 3-14 Depth contour map of Macaw Bank Area
v-CAW BANK AREA
1060I -- I - L -I
I II
I I I-1060-----------shy
k I I II
oI
-o~1 - - - L
II
-1066ii~I amp )
-1065---- -
I I
-1067
I I I
-1069 -17926 -17925 -17924- - 7923 -17922 -17921 -17920 -17919 -17918
Longitude (W)
3-16
32 Research fishing
A total of 9981 kg of fish of 44 different species were caught Of this total 24 species were marketable with a total weight of 7661 kg (77) (Table 3-2) Three species Etelis carbunculus Etelis coruscans and Caranx lugubris made up the majorityof catch by weight The average CPUE of all species was 555 kgline-hour and 405 kgline-hour for marketable species These CPUE values are average by regionalstandards and probably represent the lower bound of a commercial CPUE range This is because research fishing is usually not as directed or intense as commercial fishing
33 Biomass and MSY estimation
Unexploited hiomass was calculated using a comparative approach based on data from 18 depletion surveys from similar regions in the South Pacific These surveys are outlined in Polovina and Shomura (1990) The estimated unexploited biomass (mtnmi) per unit area for seamount and insular areas was calculated (Table 3-3) usinghabitat estimates from the hydrographic surveys (Table 3-1) relative abundance estimates from the research fishing and the depletion survey information The results of applying 3 different fishery models (Beverton-Holt Gulland and Pauly) to data from the above regions in the South Pacific suggests the potential yield at MSY of stocks in the region is 10-30 of the unexploited biomass (Polovina and Shomura 1990)Based on these calculations the potential yield at MSY is 42-126 mt for seamounts in the Tuvaluan EEZ (Table 3-3) If atoll areas are included the MSY is estimated to be 64 to 192 mt
Using the range of landings from the research fishing (250-700 kgtrip) as a lowerbound of predicted commercial catch per trip the scale of the fishery can be estimated assuming 1 vessels catch = 1mt fishtrip 1 trip = 6 days fishing + 4 days in port for a total of 10 daystrip 1 vessel makes 3 tripsmonth the fishing season is 7 months Based on these assumptions 1 vessel could make 21 tripsseason By dividing the number of trips (lmttrip) into the MSY range (42-126 mt) it is estimated the seamount fishery could support 2 to 6 vessels If the 200m contour of the islands is included hypothetically the fishery could support 3 to 9 vessels (Alternatively if each vessel should catch 150 kg of bottomfish per fishing day for 90 fishing days per year then the mid-range estimate of the MSY on the seamounts could be caught byabout 6 vessels and the mid-range estimate of the MSY on both the seamounts and around the atolls could be caught with about 9 vessels) Care should be taken in applying an analysis of this type to the island contour as it assumes the bottomfishstocks are currently unexploited in those areas Furthermore the total allowable catch and thererore the number of fishing vessels will need to be restricted below the above estimates if financial considerations require the maintenance of high CPUEs
Finally it should be noted that the MSY estimates presented here are based on the results of research fishing trials and represent a preliminary estimate of yield after the commercial fishery reaches an equilibrium exploitation level As the commercial fisherydevelops catch and effort data should be collected to create a time series database which can be used to refine the MSY estimates
3-17 c
Table 3-2 Total catch by number and weight (marketable specieb only)
Species
A furcatus
A rutfans
A virescens
E carbunculus
E coruscans
E radiosus
P lausakari
P auricila
P filamentousus
P flavipinnus
P multidens
P zonatus
E areolatus
E chlorostigma
E fasciatus
E morrhua
Eseptemfasciatus
V out
V albomarginata
Other grouper
C ignobilis
C lugubris
S susmerili
S rivoliana
TOTAL
Weight(kq)
121
6352
1369
16827
9624
627
1336
1090
5200
3698
685
3366
160
519
20
3292
5389
263
150
356
452
13435
540
1640
76608
3-18
Percent of Total Weight ()
016
829
179
2196
1256
082
174
142
679
483
089
439
021
068
003
430
703
034
020
06
059
1754
070
214
10000
Table 3-3 Unexploited biomass and MSY range for Tuvalu
[Fishable Habitat Boo (mt) MSY Range(mt
Seamounts 421 42- 126
Islands 218 22 - 65
Total 639 64- 192
3-19
40 CONCLUSION
The hydrographic surveys on approximately 95 of Tuvalus fishable seamount and submerged bank habitat taken by the project staff on research and test fishing cruises show that Tuvalus distant seamounts have about 248 nautical miles of botomfish habitat as defined by the 200 m isobath or depth contour Together with the fishable habitat near the islands Tuvalu has a total 200 m depth contour of about 376 nautical miles The associated unexploited biomass of Tuvalus deep-water bottomfish on the distant seamounts is estimated at 421 mt while that for all of the Tuvalu EEZ is estimated at 639 mt The estimated MSY range for Tuvalus seamounts is 42-126 mtand the estimated MSY range for the entire Tuvalu EEZ is 64-192 mt Based on theseMSY estimates it has been calculated that this fishery could potentially support about 4 vessels fishing on the distant seamounts and about 2 additional vessels fishingaround Tuvalus islands
Contour maps of all of Tuvalus distant seamounts and 3-dimensional profiles of the smaller seamounts have been prepared and should prove useful to the Government of Tuvalu and to new entrants to the fishery
This final biological assessment by the Tuvalu Bottomfish Project concludes that Tuvalu does indeed have sufficient bottomfish habitat stock biomass and MSY to warrant the development of a modest commercial bottomfishing industry
4-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1
ABBREv ATIONS
CPUE Catch per unit effort
EEZ Exclusive Economic Zone
FAD Fish aggregating device
GPS Geographical positioning system
GOT Government of Tuvalu
MRA Marine Resource Adviser
MSY Maximum sustainable yield
NAFICOT National Fishing Corporation of Tuvalu
NMI Nautical mile
PCC Project Coordination Committee
PIMAR Pacific Island Marine Resource
RDO Regional Development Office
SP South Pacific
USAID United States Agency for International Development
v
TUVALU BOTTOMFISH PROJECT FINAL BIOLOGICAL ASSESSMENT
10 EXECUTIVE SUMMARY
Twenty-nine iesearch cruises were completedduring the biological assessment phaseof the project using the Government of Tuvalu vessel the RV Manaui Thirteen different geographical areas were hydrographically surveyed and systematically fished Included in the areas surveyed were 2 previously unknown and uncharted seamountsRDA Bank and Takalo Bank which were located and hydrographically surveyed A total of 9981 kg of fish of 44 different species were caught during research fishingoperations Of this total 24 species were marketable with atotal weight of 7661 kgThree species Eteis carbunculus Etelis coruscans and Caranx lugubris made up the majority of catch by weight The average CPUE of all species was 555 kgline-hourand 405 kgline-hour for marketable species values similar to other regions in theSouth Pacific Based on hydrographic research survey results the total length of the 200 m contour (seamounts islands and banks) is estimated to be 376 nautical miles (nmi) within the Tuvalu EEZ (The area defined by the 200 m depth contour (isobath)has become a standard measure of bottomfish habitat useful in calculating the estimated biomass and fish stock and in comparing habitat size among various geographic areas throughout the South Pacific) The associated unexploited biomassof deep-water bottomfish is estimated to be 639 mt Estimated yield at MSY rangesfrom 64 to 192 mt Based on these MSY estimates it has been calculated that this fishery could potentially support about Avessels fishing on the distant seamounts and about 2 additional vessels fishing around Tuvalus islands
1-1
20 INTRODUCTION
The Republic of Tuvalu consists of nine emergent coral atolls and several submergedbanks lying between 4-140S latitude and 1720 E to 1760 VV longitude The Exclusive Economic Zone (EEZ) of the Republic of Tuvalu covers approximately 600000 km 2
(Figure 2-1) The Government of Tuvalu considers marine resources their mostimportant natural asset It realizes that while exploitation of deep-water bottomfish fishery resources could provide potential economic development tropical deep-waterbottomfish have a long life span slow growth rate and variable larval recruitmentwhich make these species highly susceptible to over-fishing Therefore to scale aviable long-term commercial fishery it is imperative that the sustainable yield of bottomfish stocks within the EEZ first be estimated Several approaches can be used to determine maximum sustainable yield (MSY) for an exploited commercial fisherydepending on the type quality and quantity of data available Most of theseapproaches depend on an extensive time series of catch-per-unit-effort (CPUE) data or a large sample of both CPUE and length data Unfortunately time and budgetconstraints precluded this type of research program and analysis for the Tuvaluan bottomfish stock However relative abundance and hydrographic data collected in this program allow the unexploited biomass within the EEZ to be estimated The range of MSY values can then be calculated for the unexploited stock
2-1
_ _
Figure 2-1 R
epublic of T
uvalu EEZ
tl
__ ___I _
_ _
_ I
---- _
S
- -
I i
_ _
_ _
2-2
0
30 BIOLOGICAL ASSESSMENT
31 Hydrographic program
Twenty-nine research cruises were completed during the assessment phase of theproject The Government of Tuvalu vessel the RV Manaui was used exclusively as the research platform Systematic surveys were conducted throughout the archipelago(Figure 3-1) to provide information on local bathymetry species composition lengthfrequency catch rates and depth distributions
One hundred one (101) data sets were compiled from the data collected during the biological assessment phase of the project The data were entered into database software in Tuvalu These data were subsequently sent to the RDA Marine Biologistfor analysis Statistical analyses were done using the SAS statistical packageHydrographic data were analyzed and plotted using a commercial digitizing templateand Quattro Pro and SURFER hydrographic plotting software
Hydrographic measurements were taken using a GPS positioning unit and a color sounding chromoscope From this data hydrographic chartlets of areas of potentialfishery habitat were produced and plotted Approximately 95 of fishable seamount and submerged bank habitat in the Tuvaluan Archipelago was surveyed byhydrographic measurements and research fishing During the course of fishing andhydrographic operations five small seamounts were located and charted (Figures 3-2 through 3-11) In addition the poorly charted submerged bank areas in the south ofthe archipelago (Kosciusco Bank Bayonnaise Bank and Macaw Bank areas) wereextensively surveyed (Figures 3-12 3-13 and 3-14) The hydrographic data were digitized using the electronic template to calculate the length of the 200 m contour foreach seamount or bank system Potential fishery habitat expressed as the length of the 200 m contour is given in Table 3-1
3-1
Figure 3-1 S
urvey areas of the islands banks and seam
ounts of Tuvalu
-CD
I 0
2
1r4pj
_ _
_ shy
oc
(S) epnjpe shy
Arrow
s denote survey areas
3-2
Table 3-1 Length of 200m isobath within the Tuvalu EEZ
Bank
Luao
Kosciusko-Martha-Niulakita
Macaw
RDA
Talie
Bayonnaise
Hera
Takalo
Roseb
Total (seamounts)
Total (islands)
Total (Tuvalu)
Isobath Length (nautical miles)
672
8047
2479
175
323
9562
965
1212
1331
24766
12820C
37586
The large seamount surface extending from Niulakita was included in the 200 m isobath measurement for Kosciusko Martha Bank was also included with the Kosciusko Bank b The isobath length for Rose Bank is presented here separately but it is sufficiently indistinguishable from Kosciusko Bank that it could as well have been included along with Martha Bank with the isobath length for Kosciusko Bank
C Reference Dalzell and Preston 1991
3-3
Figure 3-2 Depth contour map of Luao Bank
10 153
-10157
-10161
-l0165
-10169
-10173
-10177
j_
f_
L_
LUAO BANK
=shy
-_
_
Q
_
-10181 T
-10197 ---- - -0 F -10201
-179708 -179703 -179698 -179693
I oncitude (W) -179688
3-4 12
Figure 3-3 3-dimensional profile of Luao Bank
LUAO SANK
3-5 1
C
Figure 3-4 D
epth contour map o
f RD
A B
ank
I1A
-
_
_ __
7
-17 k
V___ I
C
4J
In
D 0
I
I
b
d
N
I
I
ii p
Nr-
IN
I
N
I
0
3-6
Figure 3-5 3-dim
ensional profile of R
DA
B
ank
w
z z lt
S-
let-
ci-d
ti-IC
O-
Z-
-ee-
ZS
-E
G-
60C-
5C
fshy
3-7
Figure 3-6 Depth contour map of Talie Bank
-6226
TALIE BANK
-6229 - - - -I -
-62 3 1
-( -6234 -7
i
-shy_
7 (NT--- -shy
_
-6237
-6240
S-6243
-62436-
_
I
-
- -
t
- -
- -
~ ~1~-
I
PI
--1 - - - -
shy
-I- - - -
-6249
176324 1763327 176330 1763-3 176336
Longitude 176339
(E) 176342 176345 1763
3-8
Figure 3-7 3-dimensional profile of Talie Bank
TeI Le Ben k
3-9
Figure 3-8 Depth contour map of Hera Bank
HERA BANK
-1215
0 -12160
Q
j 12169 - -
- 12 18 5 -179251 -179242 -179233 -179224 -1792 14
I r -179205 -179196
Longitude (W)
3-10
Figure 3-9 3-dimensional profile of Hera Bank
Hera Benk
3-11
Figure 3-10 Depth contour map of Takalo Bank
TAKALO BANK -1144
-1145 shy
-114
-114 0_49
- 115o0shy
-1151
-17961 -17960 -17959 -17958 -17957 -17956 -17955
Longitude (W)
3-12
Figure 3-1 1 3-dimensional profile of Takalo Bank
TekaIo Benk
C
Ic2
3-13
-1038
Figure 3-12 Depth contour map of Kosciusco Bank Area
KOSCIUSKO AREA
1042 + -1
-1046 -0
-1058-1054 -0 Cgt1 (j70
ci)i
-1067
-1071 L _ _j
- 1075 -- 1--
-1083 C __I
- 1087 fill 1 f
17937 17941 17945 17949 17953 17957 17961 17965 17969
Longitude (E) 3-14
-------
-----
Figure 3-13 Depth contour map of Bayonnaise Bank
BAYONNAISE BANK
-1158 ----- 190 -I I
I I
- --------- I
-1158 L ----- L-----GI
I -1108 ---- L- I -I I I
I I
K)I I
(f)-1188 K
-31198 -121 --------L--------L-------------shy
-J 0 K -1178 --- -- L ------- L----- -
1208------LI~p
00
-1218-- ------ L L __
II I I I I I I I
I-1228---------- -I
- L-- - 7 --- L II I II
I I
I I
-1238 -17989 -17979 -17969 -17959 -17949 -17939
Longitude (W)
3-15
Figure 3-14 Depth contour map of Macaw Bank Area
v-CAW BANK AREA
1060I -- I - L -I
I II
I I I-1060-----------shy
k I I II
oI
-o~1 - - - L
II
-1066ii~I amp )
-1065---- -
I I
-1067
I I I
-1069 -17926 -17925 -17924- - 7923 -17922 -17921 -17920 -17919 -17918
Longitude (W)
3-16
32 Research fishing
A total of 9981 kg of fish of 44 different species were caught Of this total 24 species were marketable with a total weight of 7661 kg (77) (Table 3-2) Three species Etelis carbunculus Etelis coruscans and Caranx lugubris made up the majorityof catch by weight The average CPUE of all species was 555 kgline-hour and 405 kgline-hour for marketable species These CPUE values are average by regionalstandards and probably represent the lower bound of a commercial CPUE range This is because research fishing is usually not as directed or intense as commercial fishing
33 Biomass and MSY estimation
Unexploited hiomass was calculated using a comparative approach based on data from 18 depletion surveys from similar regions in the South Pacific These surveys are outlined in Polovina and Shomura (1990) The estimated unexploited biomass (mtnmi) per unit area for seamount and insular areas was calculated (Table 3-3) usinghabitat estimates from the hydrographic surveys (Table 3-1) relative abundance estimates from the research fishing and the depletion survey information The results of applying 3 different fishery models (Beverton-Holt Gulland and Pauly) to data from the above regions in the South Pacific suggests the potential yield at MSY of stocks in the region is 10-30 of the unexploited biomass (Polovina and Shomura 1990)Based on these calculations the potential yield at MSY is 42-126 mt for seamounts in the Tuvaluan EEZ (Table 3-3) If atoll areas are included the MSY is estimated to be 64 to 192 mt
Using the range of landings from the research fishing (250-700 kgtrip) as a lowerbound of predicted commercial catch per trip the scale of the fishery can be estimated assuming 1 vessels catch = 1mt fishtrip 1 trip = 6 days fishing + 4 days in port for a total of 10 daystrip 1 vessel makes 3 tripsmonth the fishing season is 7 months Based on these assumptions 1 vessel could make 21 tripsseason By dividing the number of trips (lmttrip) into the MSY range (42-126 mt) it is estimated the seamount fishery could support 2 to 6 vessels If the 200m contour of the islands is included hypothetically the fishery could support 3 to 9 vessels (Alternatively if each vessel should catch 150 kg of bottomfish per fishing day for 90 fishing days per year then the mid-range estimate of the MSY on the seamounts could be caught byabout 6 vessels and the mid-range estimate of the MSY on both the seamounts and around the atolls could be caught with about 9 vessels) Care should be taken in applying an analysis of this type to the island contour as it assumes the bottomfishstocks are currently unexploited in those areas Furthermore the total allowable catch and thererore the number of fishing vessels will need to be restricted below the above estimates if financial considerations require the maintenance of high CPUEs
Finally it should be noted that the MSY estimates presented here are based on the results of research fishing trials and represent a preliminary estimate of yield after the commercial fishery reaches an equilibrium exploitation level As the commercial fisherydevelops catch and effort data should be collected to create a time series database which can be used to refine the MSY estimates
3-17 c
Table 3-2 Total catch by number and weight (marketable specieb only)
Species
A furcatus
A rutfans
A virescens
E carbunculus
E coruscans
E radiosus
P lausakari
P auricila
P filamentousus
P flavipinnus
P multidens
P zonatus
E areolatus
E chlorostigma
E fasciatus
E morrhua
Eseptemfasciatus
V out
V albomarginata
Other grouper
C ignobilis
C lugubris
S susmerili
S rivoliana
TOTAL
Weight(kq)
121
6352
1369
16827
9624
627
1336
1090
5200
3698
685
3366
160
519
20
3292
5389
263
150
356
452
13435
540
1640
76608
3-18
Percent of Total Weight ()
016
829
179
2196
1256
082
174
142
679
483
089
439
021
068
003
430
703
034
020
06
059
1754
070
214
10000
Table 3-3 Unexploited biomass and MSY range for Tuvalu
[Fishable Habitat Boo (mt) MSY Range(mt
Seamounts 421 42- 126
Islands 218 22 - 65
Total 639 64- 192
3-19
40 CONCLUSION
The hydrographic surveys on approximately 95 of Tuvalus fishable seamount and submerged bank habitat taken by the project staff on research and test fishing cruises show that Tuvalus distant seamounts have about 248 nautical miles of botomfish habitat as defined by the 200 m isobath or depth contour Together with the fishable habitat near the islands Tuvalu has a total 200 m depth contour of about 376 nautical miles The associated unexploited biomass of Tuvalus deep-water bottomfish on the distant seamounts is estimated at 421 mt while that for all of the Tuvalu EEZ is estimated at 639 mt The estimated MSY range for Tuvalus seamounts is 42-126 mtand the estimated MSY range for the entire Tuvalu EEZ is 64-192 mt Based on theseMSY estimates it has been calculated that this fishery could potentially support about 4 vessels fishing on the distant seamounts and about 2 additional vessels fishingaround Tuvalus islands
Contour maps of all of Tuvalus distant seamounts and 3-dimensional profiles of the smaller seamounts have been prepared and should prove useful to the Government of Tuvalu and to new entrants to the fishery
This final biological assessment by the Tuvalu Bottomfish Project concludes that Tuvalu does indeed have sufficient bottomfish habitat stock biomass and MSY to warrant the development of a modest commercial bottomfishing industry
4-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1
TUVALU BOTTOMFISH PROJECT FINAL BIOLOGICAL ASSESSMENT
10 EXECUTIVE SUMMARY
Twenty-nine iesearch cruises were completedduring the biological assessment phaseof the project using the Government of Tuvalu vessel the RV Manaui Thirteen different geographical areas were hydrographically surveyed and systematically fished Included in the areas surveyed were 2 previously unknown and uncharted seamountsRDA Bank and Takalo Bank which were located and hydrographically surveyed A total of 9981 kg of fish of 44 different species were caught during research fishingoperations Of this total 24 species were marketable with atotal weight of 7661 kgThree species Eteis carbunculus Etelis coruscans and Caranx lugubris made up the majority of catch by weight The average CPUE of all species was 555 kgline-hourand 405 kgline-hour for marketable species values similar to other regions in theSouth Pacific Based on hydrographic research survey results the total length of the 200 m contour (seamounts islands and banks) is estimated to be 376 nautical miles (nmi) within the Tuvalu EEZ (The area defined by the 200 m depth contour (isobath)has become a standard measure of bottomfish habitat useful in calculating the estimated biomass and fish stock and in comparing habitat size among various geographic areas throughout the South Pacific) The associated unexploited biomassof deep-water bottomfish is estimated to be 639 mt Estimated yield at MSY rangesfrom 64 to 192 mt Based on these MSY estimates it has been calculated that this fishery could potentially support about Avessels fishing on the distant seamounts and about 2 additional vessels fishing around Tuvalus islands
1-1
20 INTRODUCTION
The Republic of Tuvalu consists of nine emergent coral atolls and several submergedbanks lying between 4-140S latitude and 1720 E to 1760 VV longitude The Exclusive Economic Zone (EEZ) of the Republic of Tuvalu covers approximately 600000 km 2
(Figure 2-1) The Government of Tuvalu considers marine resources their mostimportant natural asset It realizes that while exploitation of deep-water bottomfish fishery resources could provide potential economic development tropical deep-waterbottomfish have a long life span slow growth rate and variable larval recruitmentwhich make these species highly susceptible to over-fishing Therefore to scale aviable long-term commercial fishery it is imperative that the sustainable yield of bottomfish stocks within the EEZ first be estimated Several approaches can be used to determine maximum sustainable yield (MSY) for an exploited commercial fisherydepending on the type quality and quantity of data available Most of theseapproaches depend on an extensive time series of catch-per-unit-effort (CPUE) data or a large sample of both CPUE and length data Unfortunately time and budgetconstraints precluded this type of research program and analysis for the Tuvaluan bottomfish stock However relative abundance and hydrographic data collected in this program allow the unexploited biomass within the EEZ to be estimated The range of MSY values can then be calculated for the unexploited stock
2-1
_ _
Figure 2-1 R
epublic of T
uvalu EEZ
tl
__ ___I _
_ _
_ I
---- _
S
- -
I i
_ _
_ _
2-2
0
30 BIOLOGICAL ASSESSMENT
31 Hydrographic program
Twenty-nine research cruises were completed during the assessment phase of theproject The Government of Tuvalu vessel the RV Manaui was used exclusively as the research platform Systematic surveys were conducted throughout the archipelago(Figure 3-1) to provide information on local bathymetry species composition lengthfrequency catch rates and depth distributions
One hundred one (101) data sets were compiled from the data collected during the biological assessment phase of the project The data were entered into database software in Tuvalu These data were subsequently sent to the RDA Marine Biologistfor analysis Statistical analyses were done using the SAS statistical packageHydrographic data were analyzed and plotted using a commercial digitizing templateand Quattro Pro and SURFER hydrographic plotting software
Hydrographic measurements were taken using a GPS positioning unit and a color sounding chromoscope From this data hydrographic chartlets of areas of potentialfishery habitat were produced and plotted Approximately 95 of fishable seamount and submerged bank habitat in the Tuvaluan Archipelago was surveyed byhydrographic measurements and research fishing During the course of fishing andhydrographic operations five small seamounts were located and charted (Figures 3-2 through 3-11) In addition the poorly charted submerged bank areas in the south ofthe archipelago (Kosciusco Bank Bayonnaise Bank and Macaw Bank areas) wereextensively surveyed (Figures 3-12 3-13 and 3-14) The hydrographic data were digitized using the electronic template to calculate the length of the 200 m contour foreach seamount or bank system Potential fishery habitat expressed as the length of the 200 m contour is given in Table 3-1
3-1
Figure 3-1 S
urvey areas of the islands banks and seam
ounts of Tuvalu
-CD
I 0
2
1r4pj
_ _
_ shy
oc
(S) epnjpe shy
Arrow
s denote survey areas
3-2
Table 3-1 Length of 200m isobath within the Tuvalu EEZ
Bank
Luao
Kosciusko-Martha-Niulakita
Macaw
RDA
Talie
Bayonnaise
Hera
Takalo
Roseb
Total (seamounts)
Total (islands)
Total (Tuvalu)
Isobath Length (nautical miles)
672
8047
2479
175
323
9562
965
1212
1331
24766
12820C
37586
The large seamount surface extending from Niulakita was included in the 200 m isobath measurement for Kosciusko Martha Bank was also included with the Kosciusko Bank b The isobath length for Rose Bank is presented here separately but it is sufficiently indistinguishable from Kosciusko Bank that it could as well have been included along with Martha Bank with the isobath length for Kosciusko Bank
C Reference Dalzell and Preston 1991
3-3
Figure 3-2 Depth contour map of Luao Bank
10 153
-10157
-10161
-l0165
-10169
-10173
-10177
j_
f_
L_
LUAO BANK
=shy
-_
_
Q
_
-10181 T
-10197 ---- - -0 F -10201
-179708 -179703 -179698 -179693
I oncitude (W) -179688
3-4 12
Figure 3-3 3-dimensional profile of Luao Bank
LUAO SANK
3-5 1
C
Figure 3-4 D
epth contour map o
f RD
A B
ank
I1A
-
_
_ __
7
-17 k
V___ I
C
4J
In
D 0
I
I
b
d
N
I
I
ii p
Nr-
IN
I
N
I
0
3-6
Figure 3-5 3-dim
ensional profile of R
DA
B
ank
w
z z lt
S-
let-
ci-d
ti-IC
O-
Z-
-ee-
ZS
-E
G-
60C-
5C
fshy
3-7
Figure 3-6 Depth contour map of Talie Bank
-6226
TALIE BANK
-6229 - - - -I -
-62 3 1
-( -6234 -7
i
-shy_
7 (NT--- -shy
_
-6237
-6240
S-6243
-62436-
_
I
-
- -
t
- -
- -
~ ~1~-
I
PI
--1 - - - -
shy
-I- - - -
-6249
176324 1763327 176330 1763-3 176336
Longitude 176339
(E) 176342 176345 1763
3-8
Figure 3-7 3-dimensional profile of Talie Bank
TeI Le Ben k
3-9
Figure 3-8 Depth contour map of Hera Bank
HERA BANK
-1215
0 -12160
Q
j 12169 - -
- 12 18 5 -179251 -179242 -179233 -179224 -1792 14
I r -179205 -179196
Longitude (W)
3-10
Figure 3-9 3-dimensional profile of Hera Bank
Hera Benk
3-11
Figure 3-10 Depth contour map of Takalo Bank
TAKALO BANK -1144
-1145 shy
-114
-114 0_49
- 115o0shy
-1151
-17961 -17960 -17959 -17958 -17957 -17956 -17955
Longitude (W)
3-12
Figure 3-1 1 3-dimensional profile of Takalo Bank
TekaIo Benk
C
Ic2
3-13
-1038
Figure 3-12 Depth contour map of Kosciusco Bank Area
KOSCIUSKO AREA
1042 + -1
-1046 -0
-1058-1054 -0 Cgt1 (j70
ci)i
-1067
-1071 L _ _j
- 1075 -- 1--
-1083 C __I
- 1087 fill 1 f
17937 17941 17945 17949 17953 17957 17961 17965 17969
Longitude (E) 3-14
-------
-----
Figure 3-13 Depth contour map of Bayonnaise Bank
BAYONNAISE BANK
-1158 ----- 190 -I I
I I
- --------- I
-1158 L ----- L-----GI
I -1108 ---- L- I -I I I
I I
K)I I
(f)-1188 K
-31198 -121 --------L--------L-------------shy
-J 0 K -1178 --- -- L ------- L----- -
1208------LI~p
00
-1218-- ------ L L __
II I I I I I I I
I-1228---------- -I
- L-- - 7 --- L II I II
I I
I I
-1238 -17989 -17979 -17969 -17959 -17949 -17939
Longitude (W)
3-15
Figure 3-14 Depth contour map of Macaw Bank Area
v-CAW BANK AREA
1060I -- I - L -I
I II
I I I-1060-----------shy
k I I II
oI
-o~1 - - - L
II
-1066ii~I amp )
-1065---- -
I I
-1067
I I I
-1069 -17926 -17925 -17924- - 7923 -17922 -17921 -17920 -17919 -17918
Longitude (W)
3-16
32 Research fishing
A total of 9981 kg of fish of 44 different species were caught Of this total 24 species were marketable with a total weight of 7661 kg (77) (Table 3-2) Three species Etelis carbunculus Etelis coruscans and Caranx lugubris made up the majorityof catch by weight The average CPUE of all species was 555 kgline-hour and 405 kgline-hour for marketable species These CPUE values are average by regionalstandards and probably represent the lower bound of a commercial CPUE range This is because research fishing is usually not as directed or intense as commercial fishing
33 Biomass and MSY estimation
Unexploited hiomass was calculated using a comparative approach based on data from 18 depletion surveys from similar regions in the South Pacific These surveys are outlined in Polovina and Shomura (1990) The estimated unexploited biomass (mtnmi) per unit area for seamount and insular areas was calculated (Table 3-3) usinghabitat estimates from the hydrographic surveys (Table 3-1) relative abundance estimates from the research fishing and the depletion survey information The results of applying 3 different fishery models (Beverton-Holt Gulland and Pauly) to data from the above regions in the South Pacific suggests the potential yield at MSY of stocks in the region is 10-30 of the unexploited biomass (Polovina and Shomura 1990)Based on these calculations the potential yield at MSY is 42-126 mt for seamounts in the Tuvaluan EEZ (Table 3-3) If atoll areas are included the MSY is estimated to be 64 to 192 mt
Using the range of landings from the research fishing (250-700 kgtrip) as a lowerbound of predicted commercial catch per trip the scale of the fishery can be estimated assuming 1 vessels catch = 1mt fishtrip 1 trip = 6 days fishing + 4 days in port for a total of 10 daystrip 1 vessel makes 3 tripsmonth the fishing season is 7 months Based on these assumptions 1 vessel could make 21 tripsseason By dividing the number of trips (lmttrip) into the MSY range (42-126 mt) it is estimated the seamount fishery could support 2 to 6 vessels If the 200m contour of the islands is included hypothetically the fishery could support 3 to 9 vessels (Alternatively if each vessel should catch 150 kg of bottomfish per fishing day for 90 fishing days per year then the mid-range estimate of the MSY on the seamounts could be caught byabout 6 vessels and the mid-range estimate of the MSY on both the seamounts and around the atolls could be caught with about 9 vessels) Care should be taken in applying an analysis of this type to the island contour as it assumes the bottomfishstocks are currently unexploited in those areas Furthermore the total allowable catch and thererore the number of fishing vessels will need to be restricted below the above estimates if financial considerations require the maintenance of high CPUEs
Finally it should be noted that the MSY estimates presented here are based on the results of research fishing trials and represent a preliminary estimate of yield after the commercial fishery reaches an equilibrium exploitation level As the commercial fisherydevelops catch and effort data should be collected to create a time series database which can be used to refine the MSY estimates
3-17 c
Table 3-2 Total catch by number and weight (marketable specieb only)
Species
A furcatus
A rutfans
A virescens
E carbunculus
E coruscans
E radiosus
P lausakari
P auricila
P filamentousus
P flavipinnus
P multidens
P zonatus
E areolatus
E chlorostigma
E fasciatus
E morrhua
Eseptemfasciatus
V out
V albomarginata
Other grouper
C ignobilis
C lugubris
S susmerili
S rivoliana
TOTAL
Weight(kq)
121
6352
1369
16827
9624
627
1336
1090
5200
3698
685
3366
160
519
20
3292
5389
263
150
356
452
13435
540
1640
76608
3-18
Percent of Total Weight ()
016
829
179
2196
1256
082
174
142
679
483
089
439
021
068
003
430
703
034
020
06
059
1754
070
214
10000
Table 3-3 Unexploited biomass and MSY range for Tuvalu
[Fishable Habitat Boo (mt) MSY Range(mt
Seamounts 421 42- 126
Islands 218 22 - 65
Total 639 64- 192
3-19
40 CONCLUSION
The hydrographic surveys on approximately 95 of Tuvalus fishable seamount and submerged bank habitat taken by the project staff on research and test fishing cruises show that Tuvalus distant seamounts have about 248 nautical miles of botomfish habitat as defined by the 200 m isobath or depth contour Together with the fishable habitat near the islands Tuvalu has a total 200 m depth contour of about 376 nautical miles The associated unexploited biomass of Tuvalus deep-water bottomfish on the distant seamounts is estimated at 421 mt while that for all of the Tuvalu EEZ is estimated at 639 mt The estimated MSY range for Tuvalus seamounts is 42-126 mtand the estimated MSY range for the entire Tuvalu EEZ is 64-192 mt Based on theseMSY estimates it has been calculated that this fishery could potentially support about 4 vessels fishing on the distant seamounts and about 2 additional vessels fishingaround Tuvalus islands
Contour maps of all of Tuvalus distant seamounts and 3-dimensional profiles of the smaller seamounts have been prepared and should prove useful to the Government of Tuvalu and to new entrants to the fishery
This final biological assessment by the Tuvalu Bottomfish Project concludes that Tuvalu does indeed have sufficient bottomfish habitat stock biomass and MSY to warrant the development of a modest commercial bottomfishing industry
4-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1
20 INTRODUCTION
The Republic of Tuvalu consists of nine emergent coral atolls and several submergedbanks lying between 4-140S latitude and 1720 E to 1760 VV longitude The Exclusive Economic Zone (EEZ) of the Republic of Tuvalu covers approximately 600000 km 2
(Figure 2-1) The Government of Tuvalu considers marine resources their mostimportant natural asset It realizes that while exploitation of deep-water bottomfish fishery resources could provide potential economic development tropical deep-waterbottomfish have a long life span slow growth rate and variable larval recruitmentwhich make these species highly susceptible to over-fishing Therefore to scale aviable long-term commercial fishery it is imperative that the sustainable yield of bottomfish stocks within the EEZ first be estimated Several approaches can be used to determine maximum sustainable yield (MSY) for an exploited commercial fisherydepending on the type quality and quantity of data available Most of theseapproaches depend on an extensive time series of catch-per-unit-effort (CPUE) data or a large sample of both CPUE and length data Unfortunately time and budgetconstraints precluded this type of research program and analysis for the Tuvaluan bottomfish stock However relative abundance and hydrographic data collected in this program allow the unexploited biomass within the EEZ to be estimated The range of MSY values can then be calculated for the unexploited stock
2-1
_ _
Figure 2-1 R
epublic of T
uvalu EEZ
tl
__ ___I _
_ _
_ I
---- _
S
- -
I i
_ _
_ _
2-2
0
30 BIOLOGICAL ASSESSMENT
31 Hydrographic program
Twenty-nine research cruises were completed during the assessment phase of theproject The Government of Tuvalu vessel the RV Manaui was used exclusively as the research platform Systematic surveys were conducted throughout the archipelago(Figure 3-1) to provide information on local bathymetry species composition lengthfrequency catch rates and depth distributions
One hundred one (101) data sets were compiled from the data collected during the biological assessment phase of the project The data were entered into database software in Tuvalu These data were subsequently sent to the RDA Marine Biologistfor analysis Statistical analyses were done using the SAS statistical packageHydrographic data were analyzed and plotted using a commercial digitizing templateand Quattro Pro and SURFER hydrographic plotting software
Hydrographic measurements were taken using a GPS positioning unit and a color sounding chromoscope From this data hydrographic chartlets of areas of potentialfishery habitat were produced and plotted Approximately 95 of fishable seamount and submerged bank habitat in the Tuvaluan Archipelago was surveyed byhydrographic measurements and research fishing During the course of fishing andhydrographic operations five small seamounts were located and charted (Figures 3-2 through 3-11) In addition the poorly charted submerged bank areas in the south ofthe archipelago (Kosciusco Bank Bayonnaise Bank and Macaw Bank areas) wereextensively surveyed (Figures 3-12 3-13 and 3-14) The hydrographic data were digitized using the electronic template to calculate the length of the 200 m contour foreach seamount or bank system Potential fishery habitat expressed as the length of the 200 m contour is given in Table 3-1
3-1
Figure 3-1 S
urvey areas of the islands banks and seam
ounts of Tuvalu
-CD
I 0
2
1r4pj
_ _
_ shy
oc
(S) epnjpe shy
Arrow
s denote survey areas
3-2
Table 3-1 Length of 200m isobath within the Tuvalu EEZ
Bank
Luao
Kosciusko-Martha-Niulakita
Macaw
RDA
Talie
Bayonnaise
Hera
Takalo
Roseb
Total (seamounts)
Total (islands)
Total (Tuvalu)
Isobath Length (nautical miles)
672
8047
2479
175
323
9562
965
1212
1331
24766
12820C
37586
The large seamount surface extending from Niulakita was included in the 200 m isobath measurement for Kosciusko Martha Bank was also included with the Kosciusko Bank b The isobath length for Rose Bank is presented here separately but it is sufficiently indistinguishable from Kosciusko Bank that it could as well have been included along with Martha Bank with the isobath length for Kosciusko Bank
C Reference Dalzell and Preston 1991
3-3
Figure 3-2 Depth contour map of Luao Bank
10 153
-10157
-10161
-l0165
-10169
-10173
-10177
j_
f_
L_
LUAO BANK
=shy
-_
_
Q
_
-10181 T
-10197 ---- - -0 F -10201
-179708 -179703 -179698 -179693
I oncitude (W) -179688
3-4 12
Figure 3-3 3-dimensional profile of Luao Bank
LUAO SANK
3-5 1
C
Figure 3-4 D
epth contour map o
f RD
A B
ank
I1A
-
_
_ __
7
-17 k
V___ I
C
4J
In
D 0
I
I
b
d
N
I
I
ii p
Nr-
IN
I
N
I
0
3-6
Figure 3-5 3-dim
ensional profile of R
DA
B
ank
w
z z lt
S-
let-
ci-d
ti-IC
O-
Z-
-ee-
ZS
-E
G-
60C-
5C
fshy
3-7
Figure 3-6 Depth contour map of Talie Bank
-6226
TALIE BANK
-6229 - - - -I -
-62 3 1
-( -6234 -7
i
-shy_
7 (NT--- -shy
_
-6237
-6240
S-6243
-62436-
_
I
-
- -
t
- -
- -
~ ~1~-
I
PI
--1 - - - -
shy
-I- - - -
-6249
176324 1763327 176330 1763-3 176336
Longitude 176339
(E) 176342 176345 1763
3-8
Figure 3-7 3-dimensional profile of Talie Bank
TeI Le Ben k
3-9
Figure 3-8 Depth contour map of Hera Bank
HERA BANK
-1215
0 -12160
Q
j 12169 - -
- 12 18 5 -179251 -179242 -179233 -179224 -1792 14
I r -179205 -179196
Longitude (W)
3-10
Figure 3-9 3-dimensional profile of Hera Bank
Hera Benk
3-11
Figure 3-10 Depth contour map of Takalo Bank
TAKALO BANK -1144
-1145 shy
-114
-114 0_49
- 115o0shy
-1151
-17961 -17960 -17959 -17958 -17957 -17956 -17955
Longitude (W)
3-12
Figure 3-1 1 3-dimensional profile of Takalo Bank
TekaIo Benk
C
Ic2
3-13
-1038
Figure 3-12 Depth contour map of Kosciusco Bank Area
KOSCIUSKO AREA
1042 + -1
-1046 -0
-1058-1054 -0 Cgt1 (j70
ci)i
-1067
-1071 L _ _j
- 1075 -- 1--
-1083 C __I
- 1087 fill 1 f
17937 17941 17945 17949 17953 17957 17961 17965 17969
Longitude (E) 3-14
-------
-----
Figure 3-13 Depth contour map of Bayonnaise Bank
BAYONNAISE BANK
-1158 ----- 190 -I I
I I
- --------- I
-1158 L ----- L-----GI
I -1108 ---- L- I -I I I
I I
K)I I
(f)-1188 K
-31198 -121 --------L--------L-------------shy
-J 0 K -1178 --- -- L ------- L----- -
1208------LI~p
00
-1218-- ------ L L __
II I I I I I I I
I-1228---------- -I
- L-- - 7 --- L II I II
I I
I I
-1238 -17989 -17979 -17969 -17959 -17949 -17939
Longitude (W)
3-15
Figure 3-14 Depth contour map of Macaw Bank Area
v-CAW BANK AREA
1060I -- I - L -I
I II
I I I-1060-----------shy
k I I II
oI
-o~1 - - - L
II
-1066ii~I amp )
-1065---- -
I I
-1067
I I I
-1069 -17926 -17925 -17924- - 7923 -17922 -17921 -17920 -17919 -17918
Longitude (W)
3-16
32 Research fishing
A total of 9981 kg of fish of 44 different species were caught Of this total 24 species were marketable with a total weight of 7661 kg (77) (Table 3-2) Three species Etelis carbunculus Etelis coruscans and Caranx lugubris made up the majorityof catch by weight The average CPUE of all species was 555 kgline-hour and 405 kgline-hour for marketable species These CPUE values are average by regionalstandards and probably represent the lower bound of a commercial CPUE range This is because research fishing is usually not as directed or intense as commercial fishing
33 Biomass and MSY estimation
Unexploited hiomass was calculated using a comparative approach based on data from 18 depletion surveys from similar regions in the South Pacific These surveys are outlined in Polovina and Shomura (1990) The estimated unexploited biomass (mtnmi) per unit area for seamount and insular areas was calculated (Table 3-3) usinghabitat estimates from the hydrographic surveys (Table 3-1) relative abundance estimates from the research fishing and the depletion survey information The results of applying 3 different fishery models (Beverton-Holt Gulland and Pauly) to data from the above regions in the South Pacific suggests the potential yield at MSY of stocks in the region is 10-30 of the unexploited biomass (Polovina and Shomura 1990)Based on these calculations the potential yield at MSY is 42-126 mt for seamounts in the Tuvaluan EEZ (Table 3-3) If atoll areas are included the MSY is estimated to be 64 to 192 mt
Using the range of landings from the research fishing (250-700 kgtrip) as a lowerbound of predicted commercial catch per trip the scale of the fishery can be estimated assuming 1 vessels catch = 1mt fishtrip 1 trip = 6 days fishing + 4 days in port for a total of 10 daystrip 1 vessel makes 3 tripsmonth the fishing season is 7 months Based on these assumptions 1 vessel could make 21 tripsseason By dividing the number of trips (lmttrip) into the MSY range (42-126 mt) it is estimated the seamount fishery could support 2 to 6 vessels If the 200m contour of the islands is included hypothetically the fishery could support 3 to 9 vessels (Alternatively if each vessel should catch 150 kg of bottomfish per fishing day for 90 fishing days per year then the mid-range estimate of the MSY on the seamounts could be caught byabout 6 vessels and the mid-range estimate of the MSY on both the seamounts and around the atolls could be caught with about 9 vessels) Care should be taken in applying an analysis of this type to the island contour as it assumes the bottomfishstocks are currently unexploited in those areas Furthermore the total allowable catch and thererore the number of fishing vessels will need to be restricted below the above estimates if financial considerations require the maintenance of high CPUEs
Finally it should be noted that the MSY estimates presented here are based on the results of research fishing trials and represent a preliminary estimate of yield after the commercial fishery reaches an equilibrium exploitation level As the commercial fisherydevelops catch and effort data should be collected to create a time series database which can be used to refine the MSY estimates
3-17 c
Table 3-2 Total catch by number and weight (marketable specieb only)
Species
A furcatus
A rutfans
A virescens
E carbunculus
E coruscans
E radiosus
P lausakari
P auricila
P filamentousus
P flavipinnus
P multidens
P zonatus
E areolatus
E chlorostigma
E fasciatus
E morrhua
Eseptemfasciatus
V out
V albomarginata
Other grouper
C ignobilis
C lugubris
S susmerili
S rivoliana
TOTAL
Weight(kq)
121
6352
1369
16827
9624
627
1336
1090
5200
3698
685
3366
160
519
20
3292
5389
263
150
356
452
13435
540
1640
76608
3-18
Percent of Total Weight ()
016
829
179
2196
1256
082
174
142
679
483
089
439
021
068
003
430
703
034
020
06
059
1754
070
214
10000
Table 3-3 Unexploited biomass and MSY range for Tuvalu
[Fishable Habitat Boo (mt) MSY Range(mt
Seamounts 421 42- 126
Islands 218 22 - 65
Total 639 64- 192
3-19
40 CONCLUSION
The hydrographic surveys on approximately 95 of Tuvalus fishable seamount and submerged bank habitat taken by the project staff on research and test fishing cruises show that Tuvalus distant seamounts have about 248 nautical miles of botomfish habitat as defined by the 200 m isobath or depth contour Together with the fishable habitat near the islands Tuvalu has a total 200 m depth contour of about 376 nautical miles The associated unexploited biomass of Tuvalus deep-water bottomfish on the distant seamounts is estimated at 421 mt while that for all of the Tuvalu EEZ is estimated at 639 mt The estimated MSY range for Tuvalus seamounts is 42-126 mtand the estimated MSY range for the entire Tuvalu EEZ is 64-192 mt Based on theseMSY estimates it has been calculated that this fishery could potentially support about 4 vessels fishing on the distant seamounts and about 2 additional vessels fishingaround Tuvalus islands
Contour maps of all of Tuvalus distant seamounts and 3-dimensional profiles of the smaller seamounts have been prepared and should prove useful to the Government of Tuvalu and to new entrants to the fishery
This final biological assessment by the Tuvalu Bottomfish Project concludes that Tuvalu does indeed have sufficient bottomfish habitat stock biomass and MSY to warrant the development of a modest commercial bottomfishing industry
4-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1
_ _
Figure 2-1 R
epublic of T
uvalu EEZ
tl
__ ___I _
_ _
_ I
---- _
S
- -
I i
_ _
_ _
2-2
0
30 BIOLOGICAL ASSESSMENT
31 Hydrographic program
Twenty-nine research cruises were completed during the assessment phase of theproject The Government of Tuvalu vessel the RV Manaui was used exclusively as the research platform Systematic surveys were conducted throughout the archipelago(Figure 3-1) to provide information on local bathymetry species composition lengthfrequency catch rates and depth distributions
One hundred one (101) data sets were compiled from the data collected during the biological assessment phase of the project The data were entered into database software in Tuvalu These data were subsequently sent to the RDA Marine Biologistfor analysis Statistical analyses were done using the SAS statistical packageHydrographic data were analyzed and plotted using a commercial digitizing templateand Quattro Pro and SURFER hydrographic plotting software
Hydrographic measurements were taken using a GPS positioning unit and a color sounding chromoscope From this data hydrographic chartlets of areas of potentialfishery habitat were produced and plotted Approximately 95 of fishable seamount and submerged bank habitat in the Tuvaluan Archipelago was surveyed byhydrographic measurements and research fishing During the course of fishing andhydrographic operations five small seamounts were located and charted (Figures 3-2 through 3-11) In addition the poorly charted submerged bank areas in the south ofthe archipelago (Kosciusco Bank Bayonnaise Bank and Macaw Bank areas) wereextensively surveyed (Figures 3-12 3-13 and 3-14) The hydrographic data were digitized using the electronic template to calculate the length of the 200 m contour foreach seamount or bank system Potential fishery habitat expressed as the length of the 200 m contour is given in Table 3-1
3-1
Figure 3-1 S
urvey areas of the islands banks and seam
ounts of Tuvalu
-CD
I 0
2
1r4pj
_ _
_ shy
oc
(S) epnjpe shy
Arrow
s denote survey areas
3-2
Table 3-1 Length of 200m isobath within the Tuvalu EEZ
Bank
Luao
Kosciusko-Martha-Niulakita
Macaw
RDA
Talie
Bayonnaise
Hera
Takalo
Roseb
Total (seamounts)
Total (islands)
Total (Tuvalu)
Isobath Length (nautical miles)
672
8047
2479
175
323
9562
965
1212
1331
24766
12820C
37586
The large seamount surface extending from Niulakita was included in the 200 m isobath measurement for Kosciusko Martha Bank was also included with the Kosciusko Bank b The isobath length for Rose Bank is presented here separately but it is sufficiently indistinguishable from Kosciusko Bank that it could as well have been included along with Martha Bank with the isobath length for Kosciusko Bank
C Reference Dalzell and Preston 1991
3-3
Figure 3-2 Depth contour map of Luao Bank
10 153
-10157
-10161
-l0165
-10169
-10173
-10177
j_
f_
L_
LUAO BANK
=shy
-_
_
Q
_
-10181 T
-10197 ---- - -0 F -10201
-179708 -179703 -179698 -179693
I oncitude (W) -179688
3-4 12
Figure 3-3 3-dimensional profile of Luao Bank
LUAO SANK
3-5 1
C
Figure 3-4 D
epth contour map o
f RD
A B
ank
I1A
-
_
_ __
7
-17 k
V___ I
C
4J
In
D 0
I
I
b
d
N
I
I
ii p
Nr-
IN
I
N
I
0
3-6
Figure 3-5 3-dim
ensional profile of R
DA
B
ank
w
z z lt
S-
let-
ci-d
ti-IC
O-
Z-
-ee-
ZS
-E
G-
60C-
5C
fshy
3-7
Figure 3-6 Depth contour map of Talie Bank
-6226
TALIE BANK
-6229 - - - -I -
-62 3 1
-( -6234 -7
i
-shy_
7 (NT--- -shy
_
-6237
-6240
S-6243
-62436-
_
I
-
- -
t
- -
- -
~ ~1~-
I
PI
--1 - - - -
shy
-I- - - -
-6249
176324 1763327 176330 1763-3 176336
Longitude 176339
(E) 176342 176345 1763
3-8
Figure 3-7 3-dimensional profile of Talie Bank
TeI Le Ben k
3-9
Figure 3-8 Depth contour map of Hera Bank
HERA BANK
-1215
0 -12160
Q
j 12169 - -
- 12 18 5 -179251 -179242 -179233 -179224 -1792 14
I r -179205 -179196
Longitude (W)
3-10
Figure 3-9 3-dimensional profile of Hera Bank
Hera Benk
3-11
Figure 3-10 Depth contour map of Takalo Bank
TAKALO BANK -1144
-1145 shy
-114
-114 0_49
- 115o0shy
-1151
-17961 -17960 -17959 -17958 -17957 -17956 -17955
Longitude (W)
3-12
Figure 3-1 1 3-dimensional profile of Takalo Bank
TekaIo Benk
C
Ic2
3-13
-1038
Figure 3-12 Depth contour map of Kosciusco Bank Area
KOSCIUSKO AREA
1042 + -1
-1046 -0
-1058-1054 -0 Cgt1 (j70
ci)i
-1067
-1071 L _ _j
- 1075 -- 1--
-1083 C __I
- 1087 fill 1 f
17937 17941 17945 17949 17953 17957 17961 17965 17969
Longitude (E) 3-14
-------
-----
Figure 3-13 Depth contour map of Bayonnaise Bank
BAYONNAISE BANK
-1158 ----- 190 -I I
I I
- --------- I
-1158 L ----- L-----GI
I -1108 ---- L- I -I I I
I I
K)I I
(f)-1188 K
-31198 -121 --------L--------L-------------shy
-J 0 K -1178 --- -- L ------- L----- -
1208------LI~p
00
-1218-- ------ L L __
II I I I I I I I
I-1228---------- -I
- L-- - 7 --- L II I II
I I
I I
-1238 -17989 -17979 -17969 -17959 -17949 -17939
Longitude (W)
3-15
Figure 3-14 Depth contour map of Macaw Bank Area
v-CAW BANK AREA
1060I -- I - L -I
I II
I I I-1060-----------shy
k I I II
oI
-o~1 - - - L
II
-1066ii~I amp )
-1065---- -
I I
-1067
I I I
-1069 -17926 -17925 -17924- - 7923 -17922 -17921 -17920 -17919 -17918
Longitude (W)
3-16
32 Research fishing
A total of 9981 kg of fish of 44 different species were caught Of this total 24 species were marketable with a total weight of 7661 kg (77) (Table 3-2) Three species Etelis carbunculus Etelis coruscans and Caranx lugubris made up the majorityof catch by weight The average CPUE of all species was 555 kgline-hour and 405 kgline-hour for marketable species These CPUE values are average by regionalstandards and probably represent the lower bound of a commercial CPUE range This is because research fishing is usually not as directed or intense as commercial fishing
33 Biomass and MSY estimation
Unexploited hiomass was calculated using a comparative approach based on data from 18 depletion surveys from similar regions in the South Pacific These surveys are outlined in Polovina and Shomura (1990) The estimated unexploited biomass (mtnmi) per unit area for seamount and insular areas was calculated (Table 3-3) usinghabitat estimates from the hydrographic surveys (Table 3-1) relative abundance estimates from the research fishing and the depletion survey information The results of applying 3 different fishery models (Beverton-Holt Gulland and Pauly) to data from the above regions in the South Pacific suggests the potential yield at MSY of stocks in the region is 10-30 of the unexploited biomass (Polovina and Shomura 1990)Based on these calculations the potential yield at MSY is 42-126 mt for seamounts in the Tuvaluan EEZ (Table 3-3) If atoll areas are included the MSY is estimated to be 64 to 192 mt
Using the range of landings from the research fishing (250-700 kgtrip) as a lowerbound of predicted commercial catch per trip the scale of the fishery can be estimated assuming 1 vessels catch = 1mt fishtrip 1 trip = 6 days fishing + 4 days in port for a total of 10 daystrip 1 vessel makes 3 tripsmonth the fishing season is 7 months Based on these assumptions 1 vessel could make 21 tripsseason By dividing the number of trips (lmttrip) into the MSY range (42-126 mt) it is estimated the seamount fishery could support 2 to 6 vessels If the 200m contour of the islands is included hypothetically the fishery could support 3 to 9 vessels (Alternatively if each vessel should catch 150 kg of bottomfish per fishing day for 90 fishing days per year then the mid-range estimate of the MSY on the seamounts could be caught byabout 6 vessels and the mid-range estimate of the MSY on both the seamounts and around the atolls could be caught with about 9 vessels) Care should be taken in applying an analysis of this type to the island contour as it assumes the bottomfishstocks are currently unexploited in those areas Furthermore the total allowable catch and thererore the number of fishing vessels will need to be restricted below the above estimates if financial considerations require the maintenance of high CPUEs
Finally it should be noted that the MSY estimates presented here are based on the results of research fishing trials and represent a preliminary estimate of yield after the commercial fishery reaches an equilibrium exploitation level As the commercial fisherydevelops catch and effort data should be collected to create a time series database which can be used to refine the MSY estimates
3-17 c
Table 3-2 Total catch by number and weight (marketable specieb only)
Species
A furcatus
A rutfans
A virescens
E carbunculus
E coruscans
E radiosus
P lausakari
P auricila
P filamentousus
P flavipinnus
P multidens
P zonatus
E areolatus
E chlorostigma
E fasciatus
E morrhua
Eseptemfasciatus
V out
V albomarginata
Other grouper
C ignobilis
C lugubris
S susmerili
S rivoliana
TOTAL
Weight(kq)
121
6352
1369
16827
9624
627
1336
1090
5200
3698
685
3366
160
519
20
3292
5389
263
150
356
452
13435
540
1640
76608
3-18
Percent of Total Weight ()
016
829
179
2196
1256
082
174
142
679
483
089
439
021
068
003
430
703
034
020
06
059
1754
070
214
10000
Table 3-3 Unexploited biomass and MSY range for Tuvalu
[Fishable Habitat Boo (mt) MSY Range(mt
Seamounts 421 42- 126
Islands 218 22 - 65
Total 639 64- 192
3-19
40 CONCLUSION
The hydrographic surveys on approximately 95 of Tuvalus fishable seamount and submerged bank habitat taken by the project staff on research and test fishing cruises show that Tuvalus distant seamounts have about 248 nautical miles of botomfish habitat as defined by the 200 m isobath or depth contour Together with the fishable habitat near the islands Tuvalu has a total 200 m depth contour of about 376 nautical miles The associated unexploited biomass of Tuvalus deep-water bottomfish on the distant seamounts is estimated at 421 mt while that for all of the Tuvalu EEZ is estimated at 639 mt The estimated MSY range for Tuvalus seamounts is 42-126 mtand the estimated MSY range for the entire Tuvalu EEZ is 64-192 mt Based on theseMSY estimates it has been calculated that this fishery could potentially support about 4 vessels fishing on the distant seamounts and about 2 additional vessels fishingaround Tuvalus islands
Contour maps of all of Tuvalus distant seamounts and 3-dimensional profiles of the smaller seamounts have been prepared and should prove useful to the Government of Tuvalu and to new entrants to the fishery
This final biological assessment by the Tuvalu Bottomfish Project concludes that Tuvalu does indeed have sufficient bottomfish habitat stock biomass and MSY to warrant the development of a modest commercial bottomfishing industry
4-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1
30 BIOLOGICAL ASSESSMENT
31 Hydrographic program
Twenty-nine research cruises were completed during the assessment phase of theproject The Government of Tuvalu vessel the RV Manaui was used exclusively as the research platform Systematic surveys were conducted throughout the archipelago(Figure 3-1) to provide information on local bathymetry species composition lengthfrequency catch rates and depth distributions
One hundred one (101) data sets were compiled from the data collected during the biological assessment phase of the project The data were entered into database software in Tuvalu These data were subsequently sent to the RDA Marine Biologistfor analysis Statistical analyses were done using the SAS statistical packageHydrographic data were analyzed and plotted using a commercial digitizing templateand Quattro Pro and SURFER hydrographic plotting software
Hydrographic measurements were taken using a GPS positioning unit and a color sounding chromoscope From this data hydrographic chartlets of areas of potentialfishery habitat were produced and plotted Approximately 95 of fishable seamount and submerged bank habitat in the Tuvaluan Archipelago was surveyed byhydrographic measurements and research fishing During the course of fishing andhydrographic operations five small seamounts were located and charted (Figures 3-2 through 3-11) In addition the poorly charted submerged bank areas in the south ofthe archipelago (Kosciusco Bank Bayonnaise Bank and Macaw Bank areas) wereextensively surveyed (Figures 3-12 3-13 and 3-14) The hydrographic data were digitized using the electronic template to calculate the length of the 200 m contour foreach seamount or bank system Potential fishery habitat expressed as the length of the 200 m contour is given in Table 3-1
3-1
Figure 3-1 S
urvey areas of the islands banks and seam
ounts of Tuvalu
-CD
I 0
2
1r4pj
_ _
_ shy
oc
(S) epnjpe shy
Arrow
s denote survey areas
3-2
Table 3-1 Length of 200m isobath within the Tuvalu EEZ
Bank
Luao
Kosciusko-Martha-Niulakita
Macaw
RDA
Talie
Bayonnaise
Hera
Takalo
Roseb
Total (seamounts)
Total (islands)
Total (Tuvalu)
Isobath Length (nautical miles)
672
8047
2479
175
323
9562
965
1212
1331
24766
12820C
37586
The large seamount surface extending from Niulakita was included in the 200 m isobath measurement for Kosciusko Martha Bank was also included with the Kosciusko Bank b The isobath length for Rose Bank is presented here separately but it is sufficiently indistinguishable from Kosciusko Bank that it could as well have been included along with Martha Bank with the isobath length for Kosciusko Bank
C Reference Dalzell and Preston 1991
3-3
Figure 3-2 Depth contour map of Luao Bank
10 153
-10157
-10161
-l0165
-10169
-10173
-10177
j_
f_
L_
LUAO BANK
=shy
-_
_
Q
_
-10181 T
-10197 ---- - -0 F -10201
-179708 -179703 -179698 -179693
I oncitude (W) -179688
3-4 12
Figure 3-3 3-dimensional profile of Luao Bank
LUAO SANK
3-5 1
C
Figure 3-4 D
epth contour map o
f RD
A B
ank
I1A
-
_
_ __
7
-17 k
V___ I
C
4J
In
D 0
I
I
b
d
N
I
I
ii p
Nr-
IN
I
N
I
0
3-6
Figure 3-5 3-dim
ensional profile of R
DA
B
ank
w
z z lt
S-
let-
ci-d
ti-IC
O-
Z-
-ee-
ZS
-E
G-
60C-
5C
fshy
3-7
Figure 3-6 Depth contour map of Talie Bank
-6226
TALIE BANK
-6229 - - - -I -
-62 3 1
-( -6234 -7
i
-shy_
7 (NT--- -shy
_
-6237
-6240
S-6243
-62436-
_
I
-
- -
t
- -
- -
~ ~1~-
I
PI
--1 - - - -
shy
-I- - - -
-6249
176324 1763327 176330 1763-3 176336
Longitude 176339
(E) 176342 176345 1763
3-8
Figure 3-7 3-dimensional profile of Talie Bank
TeI Le Ben k
3-9
Figure 3-8 Depth contour map of Hera Bank
HERA BANK
-1215
0 -12160
Q
j 12169 - -
- 12 18 5 -179251 -179242 -179233 -179224 -1792 14
I r -179205 -179196
Longitude (W)
3-10
Figure 3-9 3-dimensional profile of Hera Bank
Hera Benk
3-11
Figure 3-10 Depth contour map of Takalo Bank
TAKALO BANK -1144
-1145 shy
-114
-114 0_49
- 115o0shy
-1151
-17961 -17960 -17959 -17958 -17957 -17956 -17955
Longitude (W)
3-12
Figure 3-1 1 3-dimensional profile of Takalo Bank
TekaIo Benk
C
Ic2
3-13
-1038
Figure 3-12 Depth contour map of Kosciusco Bank Area
KOSCIUSKO AREA
1042 + -1
-1046 -0
-1058-1054 -0 Cgt1 (j70
ci)i
-1067
-1071 L _ _j
- 1075 -- 1--
-1083 C __I
- 1087 fill 1 f
17937 17941 17945 17949 17953 17957 17961 17965 17969
Longitude (E) 3-14
-------
-----
Figure 3-13 Depth contour map of Bayonnaise Bank
BAYONNAISE BANK
-1158 ----- 190 -I I
I I
- --------- I
-1158 L ----- L-----GI
I -1108 ---- L- I -I I I
I I
K)I I
(f)-1188 K
-31198 -121 --------L--------L-------------shy
-J 0 K -1178 --- -- L ------- L----- -
1208------LI~p
00
-1218-- ------ L L __
II I I I I I I I
I-1228---------- -I
- L-- - 7 --- L II I II
I I
I I
-1238 -17989 -17979 -17969 -17959 -17949 -17939
Longitude (W)
3-15
Figure 3-14 Depth contour map of Macaw Bank Area
v-CAW BANK AREA
1060I -- I - L -I
I II
I I I-1060-----------shy
k I I II
oI
-o~1 - - - L
II
-1066ii~I amp )
-1065---- -
I I
-1067
I I I
-1069 -17926 -17925 -17924- - 7923 -17922 -17921 -17920 -17919 -17918
Longitude (W)
3-16
32 Research fishing
A total of 9981 kg of fish of 44 different species were caught Of this total 24 species were marketable with a total weight of 7661 kg (77) (Table 3-2) Three species Etelis carbunculus Etelis coruscans and Caranx lugubris made up the majorityof catch by weight The average CPUE of all species was 555 kgline-hour and 405 kgline-hour for marketable species These CPUE values are average by regionalstandards and probably represent the lower bound of a commercial CPUE range This is because research fishing is usually not as directed or intense as commercial fishing
33 Biomass and MSY estimation
Unexploited hiomass was calculated using a comparative approach based on data from 18 depletion surveys from similar regions in the South Pacific These surveys are outlined in Polovina and Shomura (1990) The estimated unexploited biomass (mtnmi) per unit area for seamount and insular areas was calculated (Table 3-3) usinghabitat estimates from the hydrographic surveys (Table 3-1) relative abundance estimates from the research fishing and the depletion survey information The results of applying 3 different fishery models (Beverton-Holt Gulland and Pauly) to data from the above regions in the South Pacific suggests the potential yield at MSY of stocks in the region is 10-30 of the unexploited biomass (Polovina and Shomura 1990)Based on these calculations the potential yield at MSY is 42-126 mt for seamounts in the Tuvaluan EEZ (Table 3-3) If atoll areas are included the MSY is estimated to be 64 to 192 mt
Using the range of landings from the research fishing (250-700 kgtrip) as a lowerbound of predicted commercial catch per trip the scale of the fishery can be estimated assuming 1 vessels catch = 1mt fishtrip 1 trip = 6 days fishing + 4 days in port for a total of 10 daystrip 1 vessel makes 3 tripsmonth the fishing season is 7 months Based on these assumptions 1 vessel could make 21 tripsseason By dividing the number of trips (lmttrip) into the MSY range (42-126 mt) it is estimated the seamount fishery could support 2 to 6 vessels If the 200m contour of the islands is included hypothetically the fishery could support 3 to 9 vessels (Alternatively if each vessel should catch 150 kg of bottomfish per fishing day for 90 fishing days per year then the mid-range estimate of the MSY on the seamounts could be caught byabout 6 vessels and the mid-range estimate of the MSY on both the seamounts and around the atolls could be caught with about 9 vessels) Care should be taken in applying an analysis of this type to the island contour as it assumes the bottomfishstocks are currently unexploited in those areas Furthermore the total allowable catch and thererore the number of fishing vessels will need to be restricted below the above estimates if financial considerations require the maintenance of high CPUEs
Finally it should be noted that the MSY estimates presented here are based on the results of research fishing trials and represent a preliminary estimate of yield after the commercial fishery reaches an equilibrium exploitation level As the commercial fisherydevelops catch and effort data should be collected to create a time series database which can be used to refine the MSY estimates
3-17 c
Table 3-2 Total catch by number and weight (marketable specieb only)
Species
A furcatus
A rutfans
A virescens
E carbunculus
E coruscans
E radiosus
P lausakari
P auricila
P filamentousus
P flavipinnus
P multidens
P zonatus
E areolatus
E chlorostigma
E fasciatus
E morrhua
Eseptemfasciatus
V out
V albomarginata
Other grouper
C ignobilis
C lugubris
S susmerili
S rivoliana
TOTAL
Weight(kq)
121
6352
1369
16827
9624
627
1336
1090
5200
3698
685
3366
160
519
20
3292
5389
263
150
356
452
13435
540
1640
76608
3-18
Percent of Total Weight ()
016
829
179
2196
1256
082
174
142
679
483
089
439
021
068
003
430
703
034
020
06
059
1754
070
214
10000
Table 3-3 Unexploited biomass and MSY range for Tuvalu
[Fishable Habitat Boo (mt) MSY Range(mt
Seamounts 421 42- 126
Islands 218 22 - 65
Total 639 64- 192
3-19
40 CONCLUSION
The hydrographic surveys on approximately 95 of Tuvalus fishable seamount and submerged bank habitat taken by the project staff on research and test fishing cruises show that Tuvalus distant seamounts have about 248 nautical miles of botomfish habitat as defined by the 200 m isobath or depth contour Together with the fishable habitat near the islands Tuvalu has a total 200 m depth contour of about 376 nautical miles The associated unexploited biomass of Tuvalus deep-water bottomfish on the distant seamounts is estimated at 421 mt while that for all of the Tuvalu EEZ is estimated at 639 mt The estimated MSY range for Tuvalus seamounts is 42-126 mtand the estimated MSY range for the entire Tuvalu EEZ is 64-192 mt Based on theseMSY estimates it has been calculated that this fishery could potentially support about 4 vessels fishing on the distant seamounts and about 2 additional vessels fishingaround Tuvalus islands
Contour maps of all of Tuvalus distant seamounts and 3-dimensional profiles of the smaller seamounts have been prepared and should prove useful to the Government of Tuvalu and to new entrants to the fishery
This final biological assessment by the Tuvalu Bottomfish Project concludes that Tuvalu does indeed have sufficient bottomfish habitat stock biomass and MSY to warrant the development of a modest commercial bottomfishing industry
4-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1
Figure 3-1 S
urvey areas of the islands banks and seam
ounts of Tuvalu
-CD
I 0
2
1r4pj
_ _
_ shy
oc
(S) epnjpe shy
Arrow
s denote survey areas
3-2
Table 3-1 Length of 200m isobath within the Tuvalu EEZ
Bank
Luao
Kosciusko-Martha-Niulakita
Macaw
RDA
Talie
Bayonnaise
Hera
Takalo
Roseb
Total (seamounts)
Total (islands)
Total (Tuvalu)
Isobath Length (nautical miles)
672
8047
2479
175
323
9562
965
1212
1331
24766
12820C
37586
The large seamount surface extending from Niulakita was included in the 200 m isobath measurement for Kosciusko Martha Bank was also included with the Kosciusko Bank b The isobath length for Rose Bank is presented here separately but it is sufficiently indistinguishable from Kosciusko Bank that it could as well have been included along with Martha Bank with the isobath length for Kosciusko Bank
C Reference Dalzell and Preston 1991
3-3
Figure 3-2 Depth contour map of Luao Bank
10 153
-10157
-10161
-l0165
-10169
-10173
-10177
j_
f_
L_
LUAO BANK
=shy
-_
_
Q
_
-10181 T
-10197 ---- - -0 F -10201
-179708 -179703 -179698 -179693
I oncitude (W) -179688
3-4 12
Figure 3-3 3-dimensional profile of Luao Bank
LUAO SANK
3-5 1
C
Figure 3-4 D
epth contour map o
f RD
A B
ank
I1A
-
_
_ __
7
-17 k
V___ I
C
4J
In
D 0
I
I
b
d
N
I
I
ii p
Nr-
IN
I
N
I
0
3-6
Figure 3-5 3-dim
ensional profile of R
DA
B
ank
w
z z lt
S-
let-
ci-d
ti-IC
O-
Z-
-ee-
ZS
-E
G-
60C-
5C
fshy
3-7
Figure 3-6 Depth contour map of Talie Bank
-6226
TALIE BANK
-6229 - - - -I -
-62 3 1
-( -6234 -7
i
-shy_
7 (NT--- -shy
_
-6237
-6240
S-6243
-62436-
_
I
-
- -
t
- -
- -
~ ~1~-
I
PI
--1 - - - -
shy
-I- - - -
-6249
176324 1763327 176330 1763-3 176336
Longitude 176339
(E) 176342 176345 1763
3-8
Figure 3-7 3-dimensional profile of Talie Bank
TeI Le Ben k
3-9
Figure 3-8 Depth contour map of Hera Bank
HERA BANK
-1215
0 -12160
Q
j 12169 - -
- 12 18 5 -179251 -179242 -179233 -179224 -1792 14
I r -179205 -179196
Longitude (W)
3-10
Figure 3-9 3-dimensional profile of Hera Bank
Hera Benk
3-11
Figure 3-10 Depth contour map of Takalo Bank
TAKALO BANK -1144
-1145 shy
-114
-114 0_49
- 115o0shy
-1151
-17961 -17960 -17959 -17958 -17957 -17956 -17955
Longitude (W)
3-12
Figure 3-1 1 3-dimensional profile of Takalo Bank
TekaIo Benk
C
Ic2
3-13
-1038
Figure 3-12 Depth contour map of Kosciusco Bank Area
KOSCIUSKO AREA
1042 + -1
-1046 -0
-1058-1054 -0 Cgt1 (j70
ci)i
-1067
-1071 L _ _j
- 1075 -- 1--
-1083 C __I
- 1087 fill 1 f
17937 17941 17945 17949 17953 17957 17961 17965 17969
Longitude (E) 3-14
-------
-----
Figure 3-13 Depth contour map of Bayonnaise Bank
BAYONNAISE BANK
-1158 ----- 190 -I I
I I
- --------- I
-1158 L ----- L-----GI
I -1108 ---- L- I -I I I
I I
K)I I
(f)-1188 K
-31198 -121 --------L--------L-------------shy
-J 0 K -1178 --- -- L ------- L----- -
1208------LI~p
00
-1218-- ------ L L __
II I I I I I I I
I-1228---------- -I
- L-- - 7 --- L II I II
I I
I I
-1238 -17989 -17979 -17969 -17959 -17949 -17939
Longitude (W)
3-15
Figure 3-14 Depth contour map of Macaw Bank Area
v-CAW BANK AREA
1060I -- I - L -I
I II
I I I-1060-----------shy
k I I II
oI
-o~1 - - - L
II
-1066ii~I amp )
-1065---- -
I I
-1067
I I I
-1069 -17926 -17925 -17924- - 7923 -17922 -17921 -17920 -17919 -17918
Longitude (W)
3-16
32 Research fishing
A total of 9981 kg of fish of 44 different species were caught Of this total 24 species were marketable with a total weight of 7661 kg (77) (Table 3-2) Three species Etelis carbunculus Etelis coruscans and Caranx lugubris made up the majorityof catch by weight The average CPUE of all species was 555 kgline-hour and 405 kgline-hour for marketable species These CPUE values are average by regionalstandards and probably represent the lower bound of a commercial CPUE range This is because research fishing is usually not as directed or intense as commercial fishing
33 Biomass and MSY estimation
Unexploited hiomass was calculated using a comparative approach based on data from 18 depletion surveys from similar regions in the South Pacific These surveys are outlined in Polovina and Shomura (1990) The estimated unexploited biomass (mtnmi) per unit area for seamount and insular areas was calculated (Table 3-3) usinghabitat estimates from the hydrographic surveys (Table 3-1) relative abundance estimates from the research fishing and the depletion survey information The results of applying 3 different fishery models (Beverton-Holt Gulland and Pauly) to data from the above regions in the South Pacific suggests the potential yield at MSY of stocks in the region is 10-30 of the unexploited biomass (Polovina and Shomura 1990)Based on these calculations the potential yield at MSY is 42-126 mt for seamounts in the Tuvaluan EEZ (Table 3-3) If atoll areas are included the MSY is estimated to be 64 to 192 mt
Using the range of landings from the research fishing (250-700 kgtrip) as a lowerbound of predicted commercial catch per trip the scale of the fishery can be estimated assuming 1 vessels catch = 1mt fishtrip 1 trip = 6 days fishing + 4 days in port for a total of 10 daystrip 1 vessel makes 3 tripsmonth the fishing season is 7 months Based on these assumptions 1 vessel could make 21 tripsseason By dividing the number of trips (lmttrip) into the MSY range (42-126 mt) it is estimated the seamount fishery could support 2 to 6 vessels If the 200m contour of the islands is included hypothetically the fishery could support 3 to 9 vessels (Alternatively if each vessel should catch 150 kg of bottomfish per fishing day for 90 fishing days per year then the mid-range estimate of the MSY on the seamounts could be caught byabout 6 vessels and the mid-range estimate of the MSY on both the seamounts and around the atolls could be caught with about 9 vessels) Care should be taken in applying an analysis of this type to the island contour as it assumes the bottomfishstocks are currently unexploited in those areas Furthermore the total allowable catch and thererore the number of fishing vessels will need to be restricted below the above estimates if financial considerations require the maintenance of high CPUEs
Finally it should be noted that the MSY estimates presented here are based on the results of research fishing trials and represent a preliminary estimate of yield after the commercial fishery reaches an equilibrium exploitation level As the commercial fisherydevelops catch and effort data should be collected to create a time series database which can be used to refine the MSY estimates
3-17 c
Table 3-2 Total catch by number and weight (marketable specieb only)
Species
A furcatus
A rutfans
A virescens
E carbunculus
E coruscans
E radiosus
P lausakari
P auricila
P filamentousus
P flavipinnus
P multidens
P zonatus
E areolatus
E chlorostigma
E fasciatus
E morrhua
Eseptemfasciatus
V out
V albomarginata
Other grouper
C ignobilis
C lugubris
S susmerili
S rivoliana
TOTAL
Weight(kq)
121
6352
1369
16827
9624
627
1336
1090
5200
3698
685
3366
160
519
20
3292
5389
263
150
356
452
13435
540
1640
76608
3-18
Percent of Total Weight ()
016
829
179
2196
1256
082
174
142
679
483
089
439
021
068
003
430
703
034
020
06
059
1754
070
214
10000
Table 3-3 Unexploited biomass and MSY range for Tuvalu
[Fishable Habitat Boo (mt) MSY Range(mt
Seamounts 421 42- 126
Islands 218 22 - 65
Total 639 64- 192
3-19
40 CONCLUSION
The hydrographic surveys on approximately 95 of Tuvalus fishable seamount and submerged bank habitat taken by the project staff on research and test fishing cruises show that Tuvalus distant seamounts have about 248 nautical miles of botomfish habitat as defined by the 200 m isobath or depth contour Together with the fishable habitat near the islands Tuvalu has a total 200 m depth contour of about 376 nautical miles The associated unexploited biomass of Tuvalus deep-water bottomfish on the distant seamounts is estimated at 421 mt while that for all of the Tuvalu EEZ is estimated at 639 mt The estimated MSY range for Tuvalus seamounts is 42-126 mtand the estimated MSY range for the entire Tuvalu EEZ is 64-192 mt Based on theseMSY estimates it has been calculated that this fishery could potentially support about 4 vessels fishing on the distant seamounts and about 2 additional vessels fishingaround Tuvalus islands
Contour maps of all of Tuvalus distant seamounts and 3-dimensional profiles of the smaller seamounts have been prepared and should prove useful to the Government of Tuvalu and to new entrants to the fishery
This final biological assessment by the Tuvalu Bottomfish Project concludes that Tuvalu does indeed have sufficient bottomfish habitat stock biomass and MSY to warrant the development of a modest commercial bottomfishing industry
4-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1
Table 3-1 Length of 200m isobath within the Tuvalu EEZ
Bank
Luao
Kosciusko-Martha-Niulakita
Macaw
RDA
Talie
Bayonnaise
Hera
Takalo
Roseb
Total (seamounts)
Total (islands)
Total (Tuvalu)
Isobath Length (nautical miles)
672
8047
2479
175
323
9562
965
1212
1331
24766
12820C
37586
The large seamount surface extending from Niulakita was included in the 200 m isobath measurement for Kosciusko Martha Bank was also included with the Kosciusko Bank b The isobath length for Rose Bank is presented here separately but it is sufficiently indistinguishable from Kosciusko Bank that it could as well have been included along with Martha Bank with the isobath length for Kosciusko Bank
C Reference Dalzell and Preston 1991
3-3
Figure 3-2 Depth contour map of Luao Bank
10 153
-10157
-10161
-l0165
-10169
-10173
-10177
j_
f_
L_
LUAO BANK
=shy
-_
_
Q
_
-10181 T
-10197 ---- - -0 F -10201
-179708 -179703 -179698 -179693
I oncitude (W) -179688
3-4 12
Figure 3-3 3-dimensional profile of Luao Bank
LUAO SANK
3-5 1
C
Figure 3-4 D
epth contour map o
f RD
A B
ank
I1A
-
_
_ __
7
-17 k
V___ I
C
4J
In
D 0
I
I
b
d
N
I
I
ii p
Nr-
IN
I
N
I
0
3-6
Figure 3-5 3-dim
ensional profile of R
DA
B
ank
w
z z lt
S-
let-
ci-d
ti-IC
O-
Z-
-ee-
ZS
-E
G-
60C-
5C
fshy
3-7
Figure 3-6 Depth contour map of Talie Bank
-6226
TALIE BANK
-6229 - - - -I -
-62 3 1
-( -6234 -7
i
-shy_
7 (NT--- -shy
_
-6237
-6240
S-6243
-62436-
_
I
-
- -
t
- -
- -
~ ~1~-
I
PI
--1 - - - -
shy
-I- - - -
-6249
176324 1763327 176330 1763-3 176336
Longitude 176339
(E) 176342 176345 1763
3-8
Figure 3-7 3-dimensional profile of Talie Bank
TeI Le Ben k
3-9
Figure 3-8 Depth contour map of Hera Bank
HERA BANK
-1215
0 -12160
Q
j 12169 - -
- 12 18 5 -179251 -179242 -179233 -179224 -1792 14
I r -179205 -179196
Longitude (W)
3-10
Figure 3-9 3-dimensional profile of Hera Bank
Hera Benk
3-11
Figure 3-10 Depth contour map of Takalo Bank
TAKALO BANK -1144
-1145 shy
-114
-114 0_49
- 115o0shy
-1151
-17961 -17960 -17959 -17958 -17957 -17956 -17955
Longitude (W)
3-12
Figure 3-1 1 3-dimensional profile of Takalo Bank
TekaIo Benk
C
Ic2
3-13
-1038
Figure 3-12 Depth contour map of Kosciusco Bank Area
KOSCIUSKO AREA
1042 + -1
-1046 -0
-1058-1054 -0 Cgt1 (j70
ci)i
-1067
-1071 L _ _j
- 1075 -- 1--
-1083 C __I
- 1087 fill 1 f
17937 17941 17945 17949 17953 17957 17961 17965 17969
Longitude (E) 3-14
-------
-----
Figure 3-13 Depth contour map of Bayonnaise Bank
BAYONNAISE BANK
-1158 ----- 190 -I I
I I
- --------- I
-1158 L ----- L-----GI
I -1108 ---- L- I -I I I
I I
K)I I
(f)-1188 K
-31198 -121 --------L--------L-------------shy
-J 0 K -1178 --- -- L ------- L----- -
1208------LI~p
00
-1218-- ------ L L __
II I I I I I I I
I-1228---------- -I
- L-- - 7 --- L II I II
I I
I I
-1238 -17989 -17979 -17969 -17959 -17949 -17939
Longitude (W)
3-15
Figure 3-14 Depth contour map of Macaw Bank Area
v-CAW BANK AREA
1060I -- I - L -I
I II
I I I-1060-----------shy
k I I II
oI
-o~1 - - - L
II
-1066ii~I amp )
-1065---- -
I I
-1067
I I I
-1069 -17926 -17925 -17924- - 7923 -17922 -17921 -17920 -17919 -17918
Longitude (W)
3-16
32 Research fishing
A total of 9981 kg of fish of 44 different species were caught Of this total 24 species were marketable with a total weight of 7661 kg (77) (Table 3-2) Three species Etelis carbunculus Etelis coruscans and Caranx lugubris made up the majorityof catch by weight The average CPUE of all species was 555 kgline-hour and 405 kgline-hour for marketable species These CPUE values are average by regionalstandards and probably represent the lower bound of a commercial CPUE range This is because research fishing is usually not as directed or intense as commercial fishing
33 Biomass and MSY estimation
Unexploited hiomass was calculated using a comparative approach based on data from 18 depletion surveys from similar regions in the South Pacific These surveys are outlined in Polovina and Shomura (1990) The estimated unexploited biomass (mtnmi) per unit area for seamount and insular areas was calculated (Table 3-3) usinghabitat estimates from the hydrographic surveys (Table 3-1) relative abundance estimates from the research fishing and the depletion survey information The results of applying 3 different fishery models (Beverton-Holt Gulland and Pauly) to data from the above regions in the South Pacific suggests the potential yield at MSY of stocks in the region is 10-30 of the unexploited biomass (Polovina and Shomura 1990)Based on these calculations the potential yield at MSY is 42-126 mt for seamounts in the Tuvaluan EEZ (Table 3-3) If atoll areas are included the MSY is estimated to be 64 to 192 mt
Using the range of landings from the research fishing (250-700 kgtrip) as a lowerbound of predicted commercial catch per trip the scale of the fishery can be estimated assuming 1 vessels catch = 1mt fishtrip 1 trip = 6 days fishing + 4 days in port for a total of 10 daystrip 1 vessel makes 3 tripsmonth the fishing season is 7 months Based on these assumptions 1 vessel could make 21 tripsseason By dividing the number of trips (lmttrip) into the MSY range (42-126 mt) it is estimated the seamount fishery could support 2 to 6 vessels If the 200m contour of the islands is included hypothetically the fishery could support 3 to 9 vessels (Alternatively if each vessel should catch 150 kg of bottomfish per fishing day for 90 fishing days per year then the mid-range estimate of the MSY on the seamounts could be caught byabout 6 vessels and the mid-range estimate of the MSY on both the seamounts and around the atolls could be caught with about 9 vessels) Care should be taken in applying an analysis of this type to the island contour as it assumes the bottomfishstocks are currently unexploited in those areas Furthermore the total allowable catch and thererore the number of fishing vessels will need to be restricted below the above estimates if financial considerations require the maintenance of high CPUEs
Finally it should be noted that the MSY estimates presented here are based on the results of research fishing trials and represent a preliminary estimate of yield after the commercial fishery reaches an equilibrium exploitation level As the commercial fisherydevelops catch and effort data should be collected to create a time series database which can be used to refine the MSY estimates
3-17 c
Table 3-2 Total catch by number and weight (marketable specieb only)
Species
A furcatus
A rutfans
A virescens
E carbunculus
E coruscans
E radiosus
P lausakari
P auricila
P filamentousus
P flavipinnus
P multidens
P zonatus
E areolatus
E chlorostigma
E fasciatus
E morrhua
Eseptemfasciatus
V out
V albomarginata
Other grouper
C ignobilis
C lugubris
S susmerili
S rivoliana
TOTAL
Weight(kq)
121
6352
1369
16827
9624
627
1336
1090
5200
3698
685
3366
160
519
20
3292
5389
263
150
356
452
13435
540
1640
76608
3-18
Percent of Total Weight ()
016
829
179
2196
1256
082
174
142
679
483
089
439
021
068
003
430
703
034
020
06
059
1754
070
214
10000
Table 3-3 Unexploited biomass and MSY range for Tuvalu
[Fishable Habitat Boo (mt) MSY Range(mt
Seamounts 421 42- 126
Islands 218 22 - 65
Total 639 64- 192
3-19
40 CONCLUSION
The hydrographic surveys on approximately 95 of Tuvalus fishable seamount and submerged bank habitat taken by the project staff on research and test fishing cruises show that Tuvalus distant seamounts have about 248 nautical miles of botomfish habitat as defined by the 200 m isobath or depth contour Together with the fishable habitat near the islands Tuvalu has a total 200 m depth contour of about 376 nautical miles The associated unexploited biomass of Tuvalus deep-water bottomfish on the distant seamounts is estimated at 421 mt while that for all of the Tuvalu EEZ is estimated at 639 mt The estimated MSY range for Tuvalus seamounts is 42-126 mtand the estimated MSY range for the entire Tuvalu EEZ is 64-192 mt Based on theseMSY estimates it has been calculated that this fishery could potentially support about 4 vessels fishing on the distant seamounts and about 2 additional vessels fishingaround Tuvalus islands
Contour maps of all of Tuvalus distant seamounts and 3-dimensional profiles of the smaller seamounts have been prepared and should prove useful to the Government of Tuvalu and to new entrants to the fishery
This final biological assessment by the Tuvalu Bottomfish Project concludes that Tuvalu does indeed have sufficient bottomfish habitat stock biomass and MSY to warrant the development of a modest commercial bottomfishing industry
4-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1
Figure 3-2 Depth contour map of Luao Bank
10 153
-10157
-10161
-l0165
-10169
-10173
-10177
j_
f_
L_
LUAO BANK
=shy
-_
_
Q
_
-10181 T
-10197 ---- - -0 F -10201
-179708 -179703 -179698 -179693
I oncitude (W) -179688
3-4 12
Figure 3-3 3-dimensional profile of Luao Bank
LUAO SANK
3-5 1
C
Figure 3-4 D
epth contour map o
f RD
A B
ank
I1A
-
_
_ __
7
-17 k
V___ I
C
4J
In
D 0
I
I
b
d
N
I
I
ii p
Nr-
IN
I
N
I
0
3-6
Figure 3-5 3-dim
ensional profile of R
DA
B
ank
w
z z lt
S-
let-
ci-d
ti-IC
O-
Z-
-ee-
ZS
-E
G-
60C-
5C
fshy
3-7
Figure 3-6 Depth contour map of Talie Bank
-6226
TALIE BANK
-6229 - - - -I -
-62 3 1
-( -6234 -7
i
-shy_
7 (NT--- -shy
_
-6237
-6240
S-6243
-62436-
_
I
-
- -
t
- -
- -
~ ~1~-
I
PI
--1 - - - -
shy
-I- - - -
-6249
176324 1763327 176330 1763-3 176336
Longitude 176339
(E) 176342 176345 1763
3-8
Figure 3-7 3-dimensional profile of Talie Bank
TeI Le Ben k
3-9
Figure 3-8 Depth contour map of Hera Bank
HERA BANK
-1215
0 -12160
Q
j 12169 - -
- 12 18 5 -179251 -179242 -179233 -179224 -1792 14
I r -179205 -179196
Longitude (W)
3-10
Figure 3-9 3-dimensional profile of Hera Bank
Hera Benk
3-11
Figure 3-10 Depth contour map of Takalo Bank
TAKALO BANK -1144
-1145 shy
-114
-114 0_49
- 115o0shy
-1151
-17961 -17960 -17959 -17958 -17957 -17956 -17955
Longitude (W)
3-12
Figure 3-1 1 3-dimensional profile of Takalo Bank
TekaIo Benk
C
Ic2
3-13
-1038
Figure 3-12 Depth contour map of Kosciusco Bank Area
KOSCIUSKO AREA
1042 + -1
-1046 -0
-1058-1054 -0 Cgt1 (j70
ci)i
-1067
-1071 L _ _j
- 1075 -- 1--
-1083 C __I
- 1087 fill 1 f
17937 17941 17945 17949 17953 17957 17961 17965 17969
Longitude (E) 3-14
-------
-----
Figure 3-13 Depth contour map of Bayonnaise Bank
BAYONNAISE BANK
-1158 ----- 190 -I I
I I
- --------- I
-1158 L ----- L-----GI
I -1108 ---- L- I -I I I
I I
K)I I
(f)-1188 K
-31198 -121 --------L--------L-------------shy
-J 0 K -1178 --- -- L ------- L----- -
1208------LI~p
00
-1218-- ------ L L __
II I I I I I I I
I-1228---------- -I
- L-- - 7 --- L II I II
I I
I I
-1238 -17989 -17979 -17969 -17959 -17949 -17939
Longitude (W)
3-15
Figure 3-14 Depth contour map of Macaw Bank Area
v-CAW BANK AREA
1060I -- I - L -I
I II
I I I-1060-----------shy
k I I II
oI
-o~1 - - - L
II
-1066ii~I amp )
-1065---- -
I I
-1067
I I I
-1069 -17926 -17925 -17924- - 7923 -17922 -17921 -17920 -17919 -17918
Longitude (W)
3-16
32 Research fishing
A total of 9981 kg of fish of 44 different species were caught Of this total 24 species were marketable with a total weight of 7661 kg (77) (Table 3-2) Three species Etelis carbunculus Etelis coruscans and Caranx lugubris made up the majorityof catch by weight The average CPUE of all species was 555 kgline-hour and 405 kgline-hour for marketable species These CPUE values are average by regionalstandards and probably represent the lower bound of a commercial CPUE range This is because research fishing is usually not as directed or intense as commercial fishing
33 Biomass and MSY estimation
Unexploited hiomass was calculated using a comparative approach based on data from 18 depletion surveys from similar regions in the South Pacific These surveys are outlined in Polovina and Shomura (1990) The estimated unexploited biomass (mtnmi) per unit area for seamount and insular areas was calculated (Table 3-3) usinghabitat estimates from the hydrographic surveys (Table 3-1) relative abundance estimates from the research fishing and the depletion survey information The results of applying 3 different fishery models (Beverton-Holt Gulland and Pauly) to data from the above regions in the South Pacific suggests the potential yield at MSY of stocks in the region is 10-30 of the unexploited biomass (Polovina and Shomura 1990)Based on these calculations the potential yield at MSY is 42-126 mt for seamounts in the Tuvaluan EEZ (Table 3-3) If atoll areas are included the MSY is estimated to be 64 to 192 mt
Using the range of landings from the research fishing (250-700 kgtrip) as a lowerbound of predicted commercial catch per trip the scale of the fishery can be estimated assuming 1 vessels catch = 1mt fishtrip 1 trip = 6 days fishing + 4 days in port for a total of 10 daystrip 1 vessel makes 3 tripsmonth the fishing season is 7 months Based on these assumptions 1 vessel could make 21 tripsseason By dividing the number of trips (lmttrip) into the MSY range (42-126 mt) it is estimated the seamount fishery could support 2 to 6 vessels If the 200m contour of the islands is included hypothetically the fishery could support 3 to 9 vessels (Alternatively if each vessel should catch 150 kg of bottomfish per fishing day for 90 fishing days per year then the mid-range estimate of the MSY on the seamounts could be caught byabout 6 vessels and the mid-range estimate of the MSY on both the seamounts and around the atolls could be caught with about 9 vessels) Care should be taken in applying an analysis of this type to the island contour as it assumes the bottomfishstocks are currently unexploited in those areas Furthermore the total allowable catch and thererore the number of fishing vessels will need to be restricted below the above estimates if financial considerations require the maintenance of high CPUEs
Finally it should be noted that the MSY estimates presented here are based on the results of research fishing trials and represent a preliminary estimate of yield after the commercial fishery reaches an equilibrium exploitation level As the commercial fisherydevelops catch and effort data should be collected to create a time series database which can be used to refine the MSY estimates
3-17 c
Table 3-2 Total catch by number and weight (marketable specieb only)
Species
A furcatus
A rutfans
A virescens
E carbunculus
E coruscans
E radiosus
P lausakari
P auricila
P filamentousus
P flavipinnus
P multidens
P zonatus
E areolatus
E chlorostigma
E fasciatus
E morrhua
Eseptemfasciatus
V out
V albomarginata
Other grouper
C ignobilis
C lugubris
S susmerili
S rivoliana
TOTAL
Weight(kq)
121
6352
1369
16827
9624
627
1336
1090
5200
3698
685
3366
160
519
20
3292
5389
263
150
356
452
13435
540
1640
76608
3-18
Percent of Total Weight ()
016
829
179
2196
1256
082
174
142
679
483
089
439
021
068
003
430
703
034
020
06
059
1754
070
214
10000
Table 3-3 Unexploited biomass and MSY range for Tuvalu
[Fishable Habitat Boo (mt) MSY Range(mt
Seamounts 421 42- 126
Islands 218 22 - 65
Total 639 64- 192
3-19
40 CONCLUSION
The hydrographic surveys on approximately 95 of Tuvalus fishable seamount and submerged bank habitat taken by the project staff on research and test fishing cruises show that Tuvalus distant seamounts have about 248 nautical miles of botomfish habitat as defined by the 200 m isobath or depth contour Together with the fishable habitat near the islands Tuvalu has a total 200 m depth contour of about 376 nautical miles The associated unexploited biomass of Tuvalus deep-water bottomfish on the distant seamounts is estimated at 421 mt while that for all of the Tuvalu EEZ is estimated at 639 mt The estimated MSY range for Tuvalus seamounts is 42-126 mtand the estimated MSY range for the entire Tuvalu EEZ is 64-192 mt Based on theseMSY estimates it has been calculated that this fishery could potentially support about 4 vessels fishing on the distant seamounts and about 2 additional vessels fishingaround Tuvalus islands
Contour maps of all of Tuvalus distant seamounts and 3-dimensional profiles of the smaller seamounts have been prepared and should prove useful to the Government of Tuvalu and to new entrants to the fishery
This final biological assessment by the Tuvalu Bottomfish Project concludes that Tuvalu does indeed have sufficient bottomfish habitat stock biomass and MSY to warrant the development of a modest commercial bottomfishing industry
4-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1
Figure 3-3 3-dimensional profile of Luao Bank
LUAO SANK
3-5 1
C
Figure 3-4 D
epth contour map o
f RD
A B
ank
I1A
-
_
_ __
7
-17 k
V___ I
C
4J
In
D 0
I
I
b
d
N
I
I
ii p
Nr-
IN
I
N
I
0
3-6
Figure 3-5 3-dim
ensional profile of R
DA
B
ank
w
z z lt
S-
let-
ci-d
ti-IC
O-
Z-
-ee-
ZS
-E
G-
60C-
5C
fshy
3-7
Figure 3-6 Depth contour map of Talie Bank
-6226
TALIE BANK
-6229 - - - -I -
-62 3 1
-( -6234 -7
i
-shy_
7 (NT--- -shy
_
-6237
-6240
S-6243
-62436-
_
I
-
- -
t
- -
- -
~ ~1~-
I
PI
--1 - - - -
shy
-I- - - -
-6249
176324 1763327 176330 1763-3 176336
Longitude 176339
(E) 176342 176345 1763
3-8
Figure 3-7 3-dimensional profile of Talie Bank
TeI Le Ben k
3-9
Figure 3-8 Depth contour map of Hera Bank
HERA BANK
-1215
0 -12160
Q
j 12169 - -
- 12 18 5 -179251 -179242 -179233 -179224 -1792 14
I r -179205 -179196
Longitude (W)
3-10
Figure 3-9 3-dimensional profile of Hera Bank
Hera Benk
3-11
Figure 3-10 Depth contour map of Takalo Bank
TAKALO BANK -1144
-1145 shy
-114
-114 0_49
- 115o0shy
-1151
-17961 -17960 -17959 -17958 -17957 -17956 -17955
Longitude (W)
3-12
Figure 3-1 1 3-dimensional profile of Takalo Bank
TekaIo Benk
C
Ic2
3-13
-1038
Figure 3-12 Depth contour map of Kosciusco Bank Area
KOSCIUSKO AREA
1042 + -1
-1046 -0
-1058-1054 -0 Cgt1 (j70
ci)i
-1067
-1071 L _ _j
- 1075 -- 1--
-1083 C __I
- 1087 fill 1 f
17937 17941 17945 17949 17953 17957 17961 17965 17969
Longitude (E) 3-14
-------
-----
Figure 3-13 Depth contour map of Bayonnaise Bank
BAYONNAISE BANK
-1158 ----- 190 -I I
I I
- --------- I
-1158 L ----- L-----GI
I -1108 ---- L- I -I I I
I I
K)I I
(f)-1188 K
-31198 -121 --------L--------L-------------shy
-J 0 K -1178 --- -- L ------- L----- -
1208------LI~p
00
-1218-- ------ L L __
II I I I I I I I
I-1228---------- -I
- L-- - 7 --- L II I II
I I
I I
-1238 -17989 -17979 -17969 -17959 -17949 -17939
Longitude (W)
3-15
Figure 3-14 Depth contour map of Macaw Bank Area
v-CAW BANK AREA
1060I -- I - L -I
I II
I I I-1060-----------shy
k I I II
oI
-o~1 - - - L
II
-1066ii~I amp )
-1065---- -
I I
-1067
I I I
-1069 -17926 -17925 -17924- - 7923 -17922 -17921 -17920 -17919 -17918
Longitude (W)
3-16
32 Research fishing
A total of 9981 kg of fish of 44 different species were caught Of this total 24 species were marketable with a total weight of 7661 kg (77) (Table 3-2) Three species Etelis carbunculus Etelis coruscans and Caranx lugubris made up the majorityof catch by weight The average CPUE of all species was 555 kgline-hour and 405 kgline-hour for marketable species These CPUE values are average by regionalstandards and probably represent the lower bound of a commercial CPUE range This is because research fishing is usually not as directed or intense as commercial fishing
33 Biomass and MSY estimation
Unexploited hiomass was calculated using a comparative approach based on data from 18 depletion surveys from similar regions in the South Pacific These surveys are outlined in Polovina and Shomura (1990) The estimated unexploited biomass (mtnmi) per unit area for seamount and insular areas was calculated (Table 3-3) usinghabitat estimates from the hydrographic surveys (Table 3-1) relative abundance estimates from the research fishing and the depletion survey information The results of applying 3 different fishery models (Beverton-Holt Gulland and Pauly) to data from the above regions in the South Pacific suggests the potential yield at MSY of stocks in the region is 10-30 of the unexploited biomass (Polovina and Shomura 1990)Based on these calculations the potential yield at MSY is 42-126 mt for seamounts in the Tuvaluan EEZ (Table 3-3) If atoll areas are included the MSY is estimated to be 64 to 192 mt
Using the range of landings from the research fishing (250-700 kgtrip) as a lowerbound of predicted commercial catch per trip the scale of the fishery can be estimated assuming 1 vessels catch = 1mt fishtrip 1 trip = 6 days fishing + 4 days in port for a total of 10 daystrip 1 vessel makes 3 tripsmonth the fishing season is 7 months Based on these assumptions 1 vessel could make 21 tripsseason By dividing the number of trips (lmttrip) into the MSY range (42-126 mt) it is estimated the seamount fishery could support 2 to 6 vessels If the 200m contour of the islands is included hypothetically the fishery could support 3 to 9 vessels (Alternatively if each vessel should catch 150 kg of bottomfish per fishing day for 90 fishing days per year then the mid-range estimate of the MSY on the seamounts could be caught byabout 6 vessels and the mid-range estimate of the MSY on both the seamounts and around the atolls could be caught with about 9 vessels) Care should be taken in applying an analysis of this type to the island contour as it assumes the bottomfishstocks are currently unexploited in those areas Furthermore the total allowable catch and thererore the number of fishing vessels will need to be restricted below the above estimates if financial considerations require the maintenance of high CPUEs
Finally it should be noted that the MSY estimates presented here are based on the results of research fishing trials and represent a preliminary estimate of yield after the commercial fishery reaches an equilibrium exploitation level As the commercial fisherydevelops catch and effort data should be collected to create a time series database which can be used to refine the MSY estimates
3-17 c
Table 3-2 Total catch by number and weight (marketable specieb only)
Species
A furcatus
A rutfans
A virescens
E carbunculus
E coruscans
E radiosus
P lausakari
P auricila
P filamentousus
P flavipinnus
P multidens
P zonatus
E areolatus
E chlorostigma
E fasciatus
E morrhua
Eseptemfasciatus
V out
V albomarginata
Other grouper
C ignobilis
C lugubris
S susmerili
S rivoliana
TOTAL
Weight(kq)
121
6352
1369
16827
9624
627
1336
1090
5200
3698
685
3366
160
519
20
3292
5389
263
150
356
452
13435
540
1640
76608
3-18
Percent of Total Weight ()
016
829
179
2196
1256
082
174
142
679
483
089
439
021
068
003
430
703
034
020
06
059
1754
070
214
10000
Table 3-3 Unexploited biomass and MSY range for Tuvalu
[Fishable Habitat Boo (mt) MSY Range(mt
Seamounts 421 42- 126
Islands 218 22 - 65
Total 639 64- 192
3-19
40 CONCLUSION
The hydrographic surveys on approximately 95 of Tuvalus fishable seamount and submerged bank habitat taken by the project staff on research and test fishing cruises show that Tuvalus distant seamounts have about 248 nautical miles of botomfish habitat as defined by the 200 m isobath or depth contour Together with the fishable habitat near the islands Tuvalu has a total 200 m depth contour of about 376 nautical miles The associated unexploited biomass of Tuvalus deep-water bottomfish on the distant seamounts is estimated at 421 mt while that for all of the Tuvalu EEZ is estimated at 639 mt The estimated MSY range for Tuvalus seamounts is 42-126 mtand the estimated MSY range for the entire Tuvalu EEZ is 64-192 mt Based on theseMSY estimates it has been calculated that this fishery could potentially support about 4 vessels fishing on the distant seamounts and about 2 additional vessels fishingaround Tuvalus islands
Contour maps of all of Tuvalus distant seamounts and 3-dimensional profiles of the smaller seamounts have been prepared and should prove useful to the Government of Tuvalu and to new entrants to the fishery
This final biological assessment by the Tuvalu Bottomfish Project concludes that Tuvalu does indeed have sufficient bottomfish habitat stock biomass and MSY to warrant the development of a modest commercial bottomfishing industry
4-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1
C
Figure 3-4 D
epth contour map o
f RD
A B
ank
I1A
-
_
_ __
7
-17 k
V___ I
C
4J
In
D 0
I
I
b
d
N
I
I
ii p
Nr-
IN
I
N
I
0
3-6
Figure 3-5 3-dim
ensional profile of R
DA
B
ank
w
z z lt
S-
let-
ci-d
ti-IC
O-
Z-
-ee-
ZS
-E
G-
60C-
5C
fshy
3-7
Figure 3-6 Depth contour map of Talie Bank
-6226
TALIE BANK
-6229 - - - -I -
-62 3 1
-( -6234 -7
i
-shy_
7 (NT--- -shy
_
-6237
-6240
S-6243
-62436-
_
I
-
- -
t
- -
- -
~ ~1~-
I
PI
--1 - - - -
shy
-I- - - -
-6249
176324 1763327 176330 1763-3 176336
Longitude 176339
(E) 176342 176345 1763
3-8
Figure 3-7 3-dimensional profile of Talie Bank
TeI Le Ben k
3-9
Figure 3-8 Depth contour map of Hera Bank
HERA BANK
-1215
0 -12160
Q
j 12169 - -
- 12 18 5 -179251 -179242 -179233 -179224 -1792 14
I r -179205 -179196
Longitude (W)
3-10
Figure 3-9 3-dimensional profile of Hera Bank
Hera Benk
3-11
Figure 3-10 Depth contour map of Takalo Bank
TAKALO BANK -1144
-1145 shy
-114
-114 0_49
- 115o0shy
-1151
-17961 -17960 -17959 -17958 -17957 -17956 -17955
Longitude (W)
3-12
Figure 3-1 1 3-dimensional profile of Takalo Bank
TekaIo Benk
C
Ic2
3-13
-1038
Figure 3-12 Depth contour map of Kosciusco Bank Area
KOSCIUSKO AREA
1042 + -1
-1046 -0
-1058-1054 -0 Cgt1 (j70
ci)i
-1067
-1071 L _ _j
- 1075 -- 1--
-1083 C __I
- 1087 fill 1 f
17937 17941 17945 17949 17953 17957 17961 17965 17969
Longitude (E) 3-14
-------
-----
Figure 3-13 Depth contour map of Bayonnaise Bank
BAYONNAISE BANK
-1158 ----- 190 -I I
I I
- --------- I
-1158 L ----- L-----GI
I -1108 ---- L- I -I I I
I I
K)I I
(f)-1188 K
-31198 -121 --------L--------L-------------shy
-J 0 K -1178 --- -- L ------- L----- -
1208------LI~p
00
-1218-- ------ L L __
II I I I I I I I
I-1228---------- -I
- L-- - 7 --- L II I II
I I
I I
-1238 -17989 -17979 -17969 -17959 -17949 -17939
Longitude (W)
3-15
Figure 3-14 Depth contour map of Macaw Bank Area
v-CAW BANK AREA
1060I -- I - L -I
I II
I I I-1060-----------shy
k I I II
oI
-o~1 - - - L
II
-1066ii~I amp )
-1065---- -
I I
-1067
I I I
-1069 -17926 -17925 -17924- - 7923 -17922 -17921 -17920 -17919 -17918
Longitude (W)
3-16
32 Research fishing
A total of 9981 kg of fish of 44 different species were caught Of this total 24 species were marketable with a total weight of 7661 kg (77) (Table 3-2) Three species Etelis carbunculus Etelis coruscans and Caranx lugubris made up the majorityof catch by weight The average CPUE of all species was 555 kgline-hour and 405 kgline-hour for marketable species These CPUE values are average by regionalstandards and probably represent the lower bound of a commercial CPUE range This is because research fishing is usually not as directed or intense as commercial fishing
33 Biomass and MSY estimation
Unexploited hiomass was calculated using a comparative approach based on data from 18 depletion surveys from similar regions in the South Pacific These surveys are outlined in Polovina and Shomura (1990) The estimated unexploited biomass (mtnmi) per unit area for seamount and insular areas was calculated (Table 3-3) usinghabitat estimates from the hydrographic surveys (Table 3-1) relative abundance estimates from the research fishing and the depletion survey information The results of applying 3 different fishery models (Beverton-Holt Gulland and Pauly) to data from the above regions in the South Pacific suggests the potential yield at MSY of stocks in the region is 10-30 of the unexploited biomass (Polovina and Shomura 1990)Based on these calculations the potential yield at MSY is 42-126 mt for seamounts in the Tuvaluan EEZ (Table 3-3) If atoll areas are included the MSY is estimated to be 64 to 192 mt
Using the range of landings from the research fishing (250-700 kgtrip) as a lowerbound of predicted commercial catch per trip the scale of the fishery can be estimated assuming 1 vessels catch = 1mt fishtrip 1 trip = 6 days fishing + 4 days in port for a total of 10 daystrip 1 vessel makes 3 tripsmonth the fishing season is 7 months Based on these assumptions 1 vessel could make 21 tripsseason By dividing the number of trips (lmttrip) into the MSY range (42-126 mt) it is estimated the seamount fishery could support 2 to 6 vessels If the 200m contour of the islands is included hypothetically the fishery could support 3 to 9 vessels (Alternatively if each vessel should catch 150 kg of bottomfish per fishing day for 90 fishing days per year then the mid-range estimate of the MSY on the seamounts could be caught byabout 6 vessels and the mid-range estimate of the MSY on both the seamounts and around the atolls could be caught with about 9 vessels) Care should be taken in applying an analysis of this type to the island contour as it assumes the bottomfishstocks are currently unexploited in those areas Furthermore the total allowable catch and thererore the number of fishing vessels will need to be restricted below the above estimates if financial considerations require the maintenance of high CPUEs
Finally it should be noted that the MSY estimates presented here are based on the results of research fishing trials and represent a preliminary estimate of yield after the commercial fishery reaches an equilibrium exploitation level As the commercial fisherydevelops catch and effort data should be collected to create a time series database which can be used to refine the MSY estimates
3-17 c
Table 3-2 Total catch by number and weight (marketable specieb only)
Species
A furcatus
A rutfans
A virescens
E carbunculus
E coruscans
E radiosus
P lausakari
P auricila
P filamentousus
P flavipinnus
P multidens
P zonatus
E areolatus
E chlorostigma
E fasciatus
E morrhua
Eseptemfasciatus
V out
V albomarginata
Other grouper
C ignobilis
C lugubris
S susmerili
S rivoliana
TOTAL
Weight(kq)
121
6352
1369
16827
9624
627
1336
1090
5200
3698
685
3366
160
519
20
3292
5389
263
150
356
452
13435
540
1640
76608
3-18
Percent of Total Weight ()
016
829
179
2196
1256
082
174
142
679
483
089
439
021
068
003
430
703
034
020
06
059
1754
070
214
10000
Table 3-3 Unexploited biomass and MSY range for Tuvalu
[Fishable Habitat Boo (mt) MSY Range(mt
Seamounts 421 42- 126
Islands 218 22 - 65
Total 639 64- 192
3-19
40 CONCLUSION
The hydrographic surveys on approximately 95 of Tuvalus fishable seamount and submerged bank habitat taken by the project staff on research and test fishing cruises show that Tuvalus distant seamounts have about 248 nautical miles of botomfish habitat as defined by the 200 m isobath or depth contour Together with the fishable habitat near the islands Tuvalu has a total 200 m depth contour of about 376 nautical miles The associated unexploited biomass of Tuvalus deep-water bottomfish on the distant seamounts is estimated at 421 mt while that for all of the Tuvalu EEZ is estimated at 639 mt The estimated MSY range for Tuvalus seamounts is 42-126 mtand the estimated MSY range for the entire Tuvalu EEZ is 64-192 mt Based on theseMSY estimates it has been calculated that this fishery could potentially support about 4 vessels fishing on the distant seamounts and about 2 additional vessels fishingaround Tuvalus islands
Contour maps of all of Tuvalus distant seamounts and 3-dimensional profiles of the smaller seamounts have been prepared and should prove useful to the Government of Tuvalu and to new entrants to the fishery
This final biological assessment by the Tuvalu Bottomfish Project concludes that Tuvalu does indeed have sufficient bottomfish habitat stock biomass and MSY to warrant the development of a modest commercial bottomfishing industry
4-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1
Figure 3-5 3-dim
ensional profile of R
DA
B
ank
w
z z lt
S-
let-
ci-d
ti-IC
O-
Z-
-ee-
ZS
-E
G-
60C-
5C
fshy
3-7
Figure 3-6 Depth contour map of Talie Bank
-6226
TALIE BANK
-6229 - - - -I -
-62 3 1
-( -6234 -7
i
-shy_
7 (NT--- -shy
_
-6237
-6240
S-6243
-62436-
_
I
-
- -
t
- -
- -
~ ~1~-
I
PI
--1 - - - -
shy
-I- - - -
-6249
176324 1763327 176330 1763-3 176336
Longitude 176339
(E) 176342 176345 1763
3-8
Figure 3-7 3-dimensional profile of Talie Bank
TeI Le Ben k
3-9
Figure 3-8 Depth contour map of Hera Bank
HERA BANK
-1215
0 -12160
Q
j 12169 - -
- 12 18 5 -179251 -179242 -179233 -179224 -1792 14
I r -179205 -179196
Longitude (W)
3-10
Figure 3-9 3-dimensional profile of Hera Bank
Hera Benk
3-11
Figure 3-10 Depth contour map of Takalo Bank
TAKALO BANK -1144
-1145 shy
-114
-114 0_49
- 115o0shy
-1151
-17961 -17960 -17959 -17958 -17957 -17956 -17955
Longitude (W)
3-12
Figure 3-1 1 3-dimensional profile of Takalo Bank
TekaIo Benk
C
Ic2
3-13
-1038
Figure 3-12 Depth contour map of Kosciusco Bank Area
KOSCIUSKO AREA
1042 + -1
-1046 -0
-1058-1054 -0 Cgt1 (j70
ci)i
-1067
-1071 L _ _j
- 1075 -- 1--
-1083 C __I
- 1087 fill 1 f
17937 17941 17945 17949 17953 17957 17961 17965 17969
Longitude (E) 3-14
-------
-----
Figure 3-13 Depth contour map of Bayonnaise Bank
BAYONNAISE BANK
-1158 ----- 190 -I I
I I
- --------- I
-1158 L ----- L-----GI
I -1108 ---- L- I -I I I
I I
K)I I
(f)-1188 K
-31198 -121 --------L--------L-------------shy
-J 0 K -1178 --- -- L ------- L----- -
1208------LI~p
00
-1218-- ------ L L __
II I I I I I I I
I-1228---------- -I
- L-- - 7 --- L II I II
I I
I I
-1238 -17989 -17979 -17969 -17959 -17949 -17939
Longitude (W)
3-15
Figure 3-14 Depth contour map of Macaw Bank Area
v-CAW BANK AREA
1060I -- I - L -I
I II
I I I-1060-----------shy
k I I II
oI
-o~1 - - - L
II
-1066ii~I amp )
-1065---- -
I I
-1067
I I I
-1069 -17926 -17925 -17924- - 7923 -17922 -17921 -17920 -17919 -17918
Longitude (W)
3-16
32 Research fishing
A total of 9981 kg of fish of 44 different species were caught Of this total 24 species were marketable with a total weight of 7661 kg (77) (Table 3-2) Three species Etelis carbunculus Etelis coruscans and Caranx lugubris made up the majorityof catch by weight The average CPUE of all species was 555 kgline-hour and 405 kgline-hour for marketable species These CPUE values are average by regionalstandards and probably represent the lower bound of a commercial CPUE range This is because research fishing is usually not as directed or intense as commercial fishing
33 Biomass and MSY estimation
Unexploited hiomass was calculated using a comparative approach based on data from 18 depletion surveys from similar regions in the South Pacific These surveys are outlined in Polovina and Shomura (1990) The estimated unexploited biomass (mtnmi) per unit area for seamount and insular areas was calculated (Table 3-3) usinghabitat estimates from the hydrographic surveys (Table 3-1) relative abundance estimates from the research fishing and the depletion survey information The results of applying 3 different fishery models (Beverton-Holt Gulland and Pauly) to data from the above regions in the South Pacific suggests the potential yield at MSY of stocks in the region is 10-30 of the unexploited biomass (Polovina and Shomura 1990)Based on these calculations the potential yield at MSY is 42-126 mt for seamounts in the Tuvaluan EEZ (Table 3-3) If atoll areas are included the MSY is estimated to be 64 to 192 mt
Using the range of landings from the research fishing (250-700 kgtrip) as a lowerbound of predicted commercial catch per trip the scale of the fishery can be estimated assuming 1 vessels catch = 1mt fishtrip 1 trip = 6 days fishing + 4 days in port for a total of 10 daystrip 1 vessel makes 3 tripsmonth the fishing season is 7 months Based on these assumptions 1 vessel could make 21 tripsseason By dividing the number of trips (lmttrip) into the MSY range (42-126 mt) it is estimated the seamount fishery could support 2 to 6 vessels If the 200m contour of the islands is included hypothetically the fishery could support 3 to 9 vessels (Alternatively if each vessel should catch 150 kg of bottomfish per fishing day for 90 fishing days per year then the mid-range estimate of the MSY on the seamounts could be caught byabout 6 vessels and the mid-range estimate of the MSY on both the seamounts and around the atolls could be caught with about 9 vessels) Care should be taken in applying an analysis of this type to the island contour as it assumes the bottomfishstocks are currently unexploited in those areas Furthermore the total allowable catch and thererore the number of fishing vessels will need to be restricted below the above estimates if financial considerations require the maintenance of high CPUEs
Finally it should be noted that the MSY estimates presented here are based on the results of research fishing trials and represent a preliminary estimate of yield after the commercial fishery reaches an equilibrium exploitation level As the commercial fisherydevelops catch and effort data should be collected to create a time series database which can be used to refine the MSY estimates
3-17 c
Table 3-2 Total catch by number and weight (marketable specieb only)
Species
A furcatus
A rutfans
A virescens
E carbunculus
E coruscans
E radiosus
P lausakari
P auricila
P filamentousus
P flavipinnus
P multidens
P zonatus
E areolatus
E chlorostigma
E fasciatus
E morrhua
Eseptemfasciatus
V out
V albomarginata
Other grouper
C ignobilis
C lugubris
S susmerili
S rivoliana
TOTAL
Weight(kq)
121
6352
1369
16827
9624
627
1336
1090
5200
3698
685
3366
160
519
20
3292
5389
263
150
356
452
13435
540
1640
76608
3-18
Percent of Total Weight ()
016
829
179
2196
1256
082
174
142
679
483
089
439
021
068
003
430
703
034
020
06
059
1754
070
214
10000
Table 3-3 Unexploited biomass and MSY range for Tuvalu
[Fishable Habitat Boo (mt) MSY Range(mt
Seamounts 421 42- 126
Islands 218 22 - 65
Total 639 64- 192
3-19
40 CONCLUSION
The hydrographic surveys on approximately 95 of Tuvalus fishable seamount and submerged bank habitat taken by the project staff on research and test fishing cruises show that Tuvalus distant seamounts have about 248 nautical miles of botomfish habitat as defined by the 200 m isobath or depth contour Together with the fishable habitat near the islands Tuvalu has a total 200 m depth contour of about 376 nautical miles The associated unexploited biomass of Tuvalus deep-water bottomfish on the distant seamounts is estimated at 421 mt while that for all of the Tuvalu EEZ is estimated at 639 mt The estimated MSY range for Tuvalus seamounts is 42-126 mtand the estimated MSY range for the entire Tuvalu EEZ is 64-192 mt Based on theseMSY estimates it has been calculated that this fishery could potentially support about 4 vessels fishing on the distant seamounts and about 2 additional vessels fishingaround Tuvalus islands
Contour maps of all of Tuvalus distant seamounts and 3-dimensional profiles of the smaller seamounts have been prepared and should prove useful to the Government of Tuvalu and to new entrants to the fishery
This final biological assessment by the Tuvalu Bottomfish Project concludes that Tuvalu does indeed have sufficient bottomfish habitat stock biomass and MSY to warrant the development of a modest commercial bottomfishing industry
4-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1
Figure 3-6 Depth contour map of Talie Bank
-6226
TALIE BANK
-6229 - - - -I -
-62 3 1
-( -6234 -7
i
-shy_
7 (NT--- -shy
_
-6237
-6240
S-6243
-62436-
_
I
-
- -
t
- -
- -
~ ~1~-
I
PI
--1 - - - -
shy
-I- - - -
-6249
176324 1763327 176330 1763-3 176336
Longitude 176339
(E) 176342 176345 1763
3-8
Figure 3-7 3-dimensional profile of Talie Bank
TeI Le Ben k
3-9
Figure 3-8 Depth contour map of Hera Bank
HERA BANK
-1215
0 -12160
Q
j 12169 - -
- 12 18 5 -179251 -179242 -179233 -179224 -1792 14
I r -179205 -179196
Longitude (W)
3-10
Figure 3-9 3-dimensional profile of Hera Bank
Hera Benk
3-11
Figure 3-10 Depth contour map of Takalo Bank
TAKALO BANK -1144
-1145 shy
-114
-114 0_49
- 115o0shy
-1151
-17961 -17960 -17959 -17958 -17957 -17956 -17955
Longitude (W)
3-12
Figure 3-1 1 3-dimensional profile of Takalo Bank
TekaIo Benk
C
Ic2
3-13
-1038
Figure 3-12 Depth contour map of Kosciusco Bank Area
KOSCIUSKO AREA
1042 + -1
-1046 -0
-1058-1054 -0 Cgt1 (j70
ci)i
-1067
-1071 L _ _j
- 1075 -- 1--
-1083 C __I
- 1087 fill 1 f
17937 17941 17945 17949 17953 17957 17961 17965 17969
Longitude (E) 3-14
-------
-----
Figure 3-13 Depth contour map of Bayonnaise Bank
BAYONNAISE BANK
-1158 ----- 190 -I I
I I
- --------- I
-1158 L ----- L-----GI
I -1108 ---- L- I -I I I
I I
K)I I
(f)-1188 K
-31198 -121 --------L--------L-------------shy
-J 0 K -1178 --- -- L ------- L----- -
1208------LI~p
00
-1218-- ------ L L __
II I I I I I I I
I-1228---------- -I
- L-- - 7 --- L II I II
I I
I I
-1238 -17989 -17979 -17969 -17959 -17949 -17939
Longitude (W)
3-15
Figure 3-14 Depth contour map of Macaw Bank Area
v-CAW BANK AREA
1060I -- I - L -I
I II
I I I-1060-----------shy
k I I II
oI
-o~1 - - - L
II
-1066ii~I amp )
-1065---- -
I I
-1067
I I I
-1069 -17926 -17925 -17924- - 7923 -17922 -17921 -17920 -17919 -17918
Longitude (W)
3-16
32 Research fishing
A total of 9981 kg of fish of 44 different species were caught Of this total 24 species were marketable with a total weight of 7661 kg (77) (Table 3-2) Three species Etelis carbunculus Etelis coruscans and Caranx lugubris made up the majorityof catch by weight The average CPUE of all species was 555 kgline-hour and 405 kgline-hour for marketable species These CPUE values are average by regionalstandards and probably represent the lower bound of a commercial CPUE range This is because research fishing is usually not as directed or intense as commercial fishing
33 Biomass and MSY estimation
Unexploited hiomass was calculated using a comparative approach based on data from 18 depletion surveys from similar regions in the South Pacific These surveys are outlined in Polovina and Shomura (1990) The estimated unexploited biomass (mtnmi) per unit area for seamount and insular areas was calculated (Table 3-3) usinghabitat estimates from the hydrographic surveys (Table 3-1) relative abundance estimates from the research fishing and the depletion survey information The results of applying 3 different fishery models (Beverton-Holt Gulland and Pauly) to data from the above regions in the South Pacific suggests the potential yield at MSY of stocks in the region is 10-30 of the unexploited biomass (Polovina and Shomura 1990)Based on these calculations the potential yield at MSY is 42-126 mt for seamounts in the Tuvaluan EEZ (Table 3-3) If atoll areas are included the MSY is estimated to be 64 to 192 mt
Using the range of landings from the research fishing (250-700 kgtrip) as a lowerbound of predicted commercial catch per trip the scale of the fishery can be estimated assuming 1 vessels catch = 1mt fishtrip 1 trip = 6 days fishing + 4 days in port for a total of 10 daystrip 1 vessel makes 3 tripsmonth the fishing season is 7 months Based on these assumptions 1 vessel could make 21 tripsseason By dividing the number of trips (lmttrip) into the MSY range (42-126 mt) it is estimated the seamount fishery could support 2 to 6 vessels If the 200m contour of the islands is included hypothetically the fishery could support 3 to 9 vessels (Alternatively if each vessel should catch 150 kg of bottomfish per fishing day for 90 fishing days per year then the mid-range estimate of the MSY on the seamounts could be caught byabout 6 vessels and the mid-range estimate of the MSY on both the seamounts and around the atolls could be caught with about 9 vessels) Care should be taken in applying an analysis of this type to the island contour as it assumes the bottomfishstocks are currently unexploited in those areas Furthermore the total allowable catch and thererore the number of fishing vessels will need to be restricted below the above estimates if financial considerations require the maintenance of high CPUEs
Finally it should be noted that the MSY estimates presented here are based on the results of research fishing trials and represent a preliminary estimate of yield after the commercial fishery reaches an equilibrium exploitation level As the commercial fisherydevelops catch and effort data should be collected to create a time series database which can be used to refine the MSY estimates
3-17 c
Table 3-2 Total catch by number and weight (marketable specieb only)
Species
A furcatus
A rutfans
A virescens
E carbunculus
E coruscans
E radiosus
P lausakari
P auricila
P filamentousus
P flavipinnus
P multidens
P zonatus
E areolatus
E chlorostigma
E fasciatus
E morrhua
Eseptemfasciatus
V out
V albomarginata
Other grouper
C ignobilis
C lugubris
S susmerili
S rivoliana
TOTAL
Weight(kq)
121
6352
1369
16827
9624
627
1336
1090
5200
3698
685
3366
160
519
20
3292
5389
263
150
356
452
13435
540
1640
76608
3-18
Percent of Total Weight ()
016
829
179
2196
1256
082
174
142
679
483
089
439
021
068
003
430
703
034
020
06
059
1754
070
214
10000
Table 3-3 Unexploited biomass and MSY range for Tuvalu
[Fishable Habitat Boo (mt) MSY Range(mt
Seamounts 421 42- 126
Islands 218 22 - 65
Total 639 64- 192
3-19
40 CONCLUSION
The hydrographic surveys on approximately 95 of Tuvalus fishable seamount and submerged bank habitat taken by the project staff on research and test fishing cruises show that Tuvalus distant seamounts have about 248 nautical miles of botomfish habitat as defined by the 200 m isobath or depth contour Together with the fishable habitat near the islands Tuvalu has a total 200 m depth contour of about 376 nautical miles The associated unexploited biomass of Tuvalus deep-water bottomfish on the distant seamounts is estimated at 421 mt while that for all of the Tuvalu EEZ is estimated at 639 mt The estimated MSY range for Tuvalus seamounts is 42-126 mtand the estimated MSY range for the entire Tuvalu EEZ is 64-192 mt Based on theseMSY estimates it has been calculated that this fishery could potentially support about 4 vessels fishing on the distant seamounts and about 2 additional vessels fishingaround Tuvalus islands
Contour maps of all of Tuvalus distant seamounts and 3-dimensional profiles of the smaller seamounts have been prepared and should prove useful to the Government of Tuvalu and to new entrants to the fishery
This final biological assessment by the Tuvalu Bottomfish Project concludes that Tuvalu does indeed have sufficient bottomfish habitat stock biomass and MSY to warrant the development of a modest commercial bottomfishing industry
4-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1
Figure 3-7 3-dimensional profile of Talie Bank
TeI Le Ben k
3-9
Figure 3-8 Depth contour map of Hera Bank
HERA BANK
-1215
0 -12160
Q
j 12169 - -
- 12 18 5 -179251 -179242 -179233 -179224 -1792 14
I r -179205 -179196
Longitude (W)
3-10
Figure 3-9 3-dimensional profile of Hera Bank
Hera Benk
3-11
Figure 3-10 Depth contour map of Takalo Bank
TAKALO BANK -1144
-1145 shy
-114
-114 0_49
- 115o0shy
-1151
-17961 -17960 -17959 -17958 -17957 -17956 -17955
Longitude (W)
3-12
Figure 3-1 1 3-dimensional profile of Takalo Bank
TekaIo Benk
C
Ic2
3-13
-1038
Figure 3-12 Depth contour map of Kosciusco Bank Area
KOSCIUSKO AREA
1042 + -1
-1046 -0
-1058-1054 -0 Cgt1 (j70
ci)i
-1067
-1071 L _ _j
- 1075 -- 1--
-1083 C __I
- 1087 fill 1 f
17937 17941 17945 17949 17953 17957 17961 17965 17969
Longitude (E) 3-14
-------
-----
Figure 3-13 Depth contour map of Bayonnaise Bank
BAYONNAISE BANK
-1158 ----- 190 -I I
I I
- --------- I
-1158 L ----- L-----GI
I -1108 ---- L- I -I I I
I I
K)I I
(f)-1188 K
-31198 -121 --------L--------L-------------shy
-J 0 K -1178 --- -- L ------- L----- -
1208------LI~p
00
-1218-- ------ L L __
II I I I I I I I
I-1228---------- -I
- L-- - 7 --- L II I II
I I
I I
-1238 -17989 -17979 -17969 -17959 -17949 -17939
Longitude (W)
3-15
Figure 3-14 Depth contour map of Macaw Bank Area
v-CAW BANK AREA
1060I -- I - L -I
I II
I I I-1060-----------shy
k I I II
oI
-o~1 - - - L
II
-1066ii~I amp )
-1065---- -
I I
-1067
I I I
-1069 -17926 -17925 -17924- - 7923 -17922 -17921 -17920 -17919 -17918
Longitude (W)
3-16
32 Research fishing
A total of 9981 kg of fish of 44 different species were caught Of this total 24 species were marketable with a total weight of 7661 kg (77) (Table 3-2) Three species Etelis carbunculus Etelis coruscans and Caranx lugubris made up the majorityof catch by weight The average CPUE of all species was 555 kgline-hour and 405 kgline-hour for marketable species These CPUE values are average by regionalstandards and probably represent the lower bound of a commercial CPUE range This is because research fishing is usually not as directed or intense as commercial fishing
33 Biomass and MSY estimation
Unexploited hiomass was calculated using a comparative approach based on data from 18 depletion surveys from similar regions in the South Pacific These surveys are outlined in Polovina and Shomura (1990) The estimated unexploited biomass (mtnmi) per unit area for seamount and insular areas was calculated (Table 3-3) usinghabitat estimates from the hydrographic surveys (Table 3-1) relative abundance estimates from the research fishing and the depletion survey information The results of applying 3 different fishery models (Beverton-Holt Gulland and Pauly) to data from the above regions in the South Pacific suggests the potential yield at MSY of stocks in the region is 10-30 of the unexploited biomass (Polovina and Shomura 1990)Based on these calculations the potential yield at MSY is 42-126 mt for seamounts in the Tuvaluan EEZ (Table 3-3) If atoll areas are included the MSY is estimated to be 64 to 192 mt
Using the range of landings from the research fishing (250-700 kgtrip) as a lowerbound of predicted commercial catch per trip the scale of the fishery can be estimated assuming 1 vessels catch = 1mt fishtrip 1 trip = 6 days fishing + 4 days in port for a total of 10 daystrip 1 vessel makes 3 tripsmonth the fishing season is 7 months Based on these assumptions 1 vessel could make 21 tripsseason By dividing the number of trips (lmttrip) into the MSY range (42-126 mt) it is estimated the seamount fishery could support 2 to 6 vessels If the 200m contour of the islands is included hypothetically the fishery could support 3 to 9 vessels (Alternatively if each vessel should catch 150 kg of bottomfish per fishing day for 90 fishing days per year then the mid-range estimate of the MSY on the seamounts could be caught byabout 6 vessels and the mid-range estimate of the MSY on both the seamounts and around the atolls could be caught with about 9 vessels) Care should be taken in applying an analysis of this type to the island contour as it assumes the bottomfishstocks are currently unexploited in those areas Furthermore the total allowable catch and thererore the number of fishing vessels will need to be restricted below the above estimates if financial considerations require the maintenance of high CPUEs
Finally it should be noted that the MSY estimates presented here are based on the results of research fishing trials and represent a preliminary estimate of yield after the commercial fishery reaches an equilibrium exploitation level As the commercial fisherydevelops catch and effort data should be collected to create a time series database which can be used to refine the MSY estimates
3-17 c
Table 3-2 Total catch by number and weight (marketable specieb only)
Species
A furcatus
A rutfans
A virescens
E carbunculus
E coruscans
E radiosus
P lausakari
P auricila
P filamentousus
P flavipinnus
P multidens
P zonatus
E areolatus
E chlorostigma
E fasciatus
E morrhua
Eseptemfasciatus
V out
V albomarginata
Other grouper
C ignobilis
C lugubris
S susmerili
S rivoliana
TOTAL
Weight(kq)
121
6352
1369
16827
9624
627
1336
1090
5200
3698
685
3366
160
519
20
3292
5389
263
150
356
452
13435
540
1640
76608
3-18
Percent of Total Weight ()
016
829
179
2196
1256
082
174
142
679
483
089
439
021
068
003
430
703
034
020
06
059
1754
070
214
10000
Table 3-3 Unexploited biomass and MSY range for Tuvalu
[Fishable Habitat Boo (mt) MSY Range(mt
Seamounts 421 42- 126
Islands 218 22 - 65
Total 639 64- 192
3-19
40 CONCLUSION
The hydrographic surveys on approximately 95 of Tuvalus fishable seamount and submerged bank habitat taken by the project staff on research and test fishing cruises show that Tuvalus distant seamounts have about 248 nautical miles of botomfish habitat as defined by the 200 m isobath or depth contour Together with the fishable habitat near the islands Tuvalu has a total 200 m depth contour of about 376 nautical miles The associated unexploited biomass of Tuvalus deep-water bottomfish on the distant seamounts is estimated at 421 mt while that for all of the Tuvalu EEZ is estimated at 639 mt The estimated MSY range for Tuvalus seamounts is 42-126 mtand the estimated MSY range for the entire Tuvalu EEZ is 64-192 mt Based on theseMSY estimates it has been calculated that this fishery could potentially support about 4 vessels fishing on the distant seamounts and about 2 additional vessels fishingaround Tuvalus islands
Contour maps of all of Tuvalus distant seamounts and 3-dimensional profiles of the smaller seamounts have been prepared and should prove useful to the Government of Tuvalu and to new entrants to the fishery
This final biological assessment by the Tuvalu Bottomfish Project concludes that Tuvalu does indeed have sufficient bottomfish habitat stock biomass and MSY to warrant the development of a modest commercial bottomfishing industry
4-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1
Figure 3-8 Depth contour map of Hera Bank
HERA BANK
-1215
0 -12160
Q
j 12169 - -
- 12 18 5 -179251 -179242 -179233 -179224 -1792 14
I r -179205 -179196
Longitude (W)
3-10
Figure 3-9 3-dimensional profile of Hera Bank
Hera Benk
3-11
Figure 3-10 Depth contour map of Takalo Bank
TAKALO BANK -1144
-1145 shy
-114
-114 0_49
- 115o0shy
-1151
-17961 -17960 -17959 -17958 -17957 -17956 -17955
Longitude (W)
3-12
Figure 3-1 1 3-dimensional profile of Takalo Bank
TekaIo Benk
C
Ic2
3-13
-1038
Figure 3-12 Depth contour map of Kosciusco Bank Area
KOSCIUSKO AREA
1042 + -1
-1046 -0
-1058-1054 -0 Cgt1 (j70
ci)i
-1067
-1071 L _ _j
- 1075 -- 1--
-1083 C __I
- 1087 fill 1 f
17937 17941 17945 17949 17953 17957 17961 17965 17969
Longitude (E) 3-14
-------
-----
Figure 3-13 Depth contour map of Bayonnaise Bank
BAYONNAISE BANK
-1158 ----- 190 -I I
I I
- --------- I
-1158 L ----- L-----GI
I -1108 ---- L- I -I I I
I I
K)I I
(f)-1188 K
-31198 -121 --------L--------L-------------shy
-J 0 K -1178 --- -- L ------- L----- -
1208------LI~p
00
-1218-- ------ L L __
II I I I I I I I
I-1228---------- -I
- L-- - 7 --- L II I II
I I
I I
-1238 -17989 -17979 -17969 -17959 -17949 -17939
Longitude (W)
3-15
Figure 3-14 Depth contour map of Macaw Bank Area
v-CAW BANK AREA
1060I -- I - L -I
I II
I I I-1060-----------shy
k I I II
oI
-o~1 - - - L
II
-1066ii~I amp )
-1065---- -
I I
-1067
I I I
-1069 -17926 -17925 -17924- - 7923 -17922 -17921 -17920 -17919 -17918
Longitude (W)
3-16
32 Research fishing
A total of 9981 kg of fish of 44 different species were caught Of this total 24 species were marketable with a total weight of 7661 kg (77) (Table 3-2) Three species Etelis carbunculus Etelis coruscans and Caranx lugubris made up the majorityof catch by weight The average CPUE of all species was 555 kgline-hour and 405 kgline-hour for marketable species These CPUE values are average by regionalstandards and probably represent the lower bound of a commercial CPUE range This is because research fishing is usually not as directed or intense as commercial fishing
33 Biomass and MSY estimation
Unexploited hiomass was calculated using a comparative approach based on data from 18 depletion surveys from similar regions in the South Pacific These surveys are outlined in Polovina and Shomura (1990) The estimated unexploited biomass (mtnmi) per unit area for seamount and insular areas was calculated (Table 3-3) usinghabitat estimates from the hydrographic surveys (Table 3-1) relative abundance estimates from the research fishing and the depletion survey information The results of applying 3 different fishery models (Beverton-Holt Gulland and Pauly) to data from the above regions in the South Pacific suggests the potential yield at MSY of stocks in the region is 10-30 of the unexploited biomass (Polovina and Shomura 1990)Based on these calculations the potential yield at MSY is 42-126 mt for seamounts in the Tuvaluan EEZ (Table 3-3) If atoll areas are included the MSY is estimated to be 64 to 192 mt
Using the range of landings from the research fishing (250-700 kgtrip) as a lowerbound of predicted commercial catch per trip the scale of the fishery can be estimated assuming 1 vessels catch = 1mt fishtrip 1 trip = 6 days fishing + 4 days in port for a total of 10 daystrip 1 vessel makes 3 tripsmonth the fishing season is 7 months Based on these assumptions 1 vessel could make 21 tripsseason By dividing the number of trips (lmttrip) into the MSY range (42-126 mt) it is estimated the seamount fishery could support 2 to 6 vessels If the 200m contour of the islands is included hypothetically the fishery could support 3 to 9 vessels (Alternatively if each vessel should catch 150 kg of bottomfish per fishing day for 90 fishing days per year then the mid-range estimate of the MSY on the seamounts could be caught byabout 6 vessels and the mid-range estimate of the MSY on both the seamounts and around the atolls could be caught with about 9 vessels) Care should be taken in applying an analysis of this type to the island contour as it assumes the bottomfishstocks are currently unexploited in those areas Furthermore the total allowable catch and thererore the number of fishing vessels will need to be restricted below the above estimates if financial considerations require the maintenance of high CPUEs
Finally it should be noted that the MSY estimates presented here are based on the results of research fishing trials and represent a preliminary estimate of yield after the commercial fishery reaches an equilibrium exploitation level As the commercial fisherydevelops catch and effort data should be collected to create a time series database which can be used to refine the MSY estimates
3-17 c
Table 3-2 Total catch by number and weight (marketable specieb only)
Species
A furcatus
A rutfans
A virescens
E carbunculus
E coruscans
E radiosus
P lausakari
P auricila
P filamentousus
P flavipinnus
P multidens
P zonatus
E areolatus
E chlorostigma
E fasciatus
E morrhua
Eseptemfasciatus
V out
V albomarginata
Other grouper
C ignobilis
C lugubris
S susmerili
S rivoliana
TOTAL
Weight(kq)
121
6352
1369
16827
9624
627
1336
1090
5200
3698
685
3366
160
519
20
3292
5389
263
150
356
452
13435
540
1640
76608
3-18
Percent of Total Weight ()
016
829
179
2196
1256
082
174
142
679
483
089
439
021
068
003
430
703
034
020
06
059
1754
070
214
10000
Table 3-3 Unexploited biomass and MSY range for Tuvalu
[Fishable Habitat Boo (mt) MSY Range(mt
Seamounts 421 42- 126
Islands 218 22 - 65
Total 639 64- 192
3-19
40 CONCLUSION
The hydrographic surveys on approximately 95 of Tuvalus fishable seamount and submerged bank habitat taken by the project staff on research and test fishing cruises show that Tuvalus distant seamounts have about 248 nautical miles of botomfish habitat as defined by the 200 m isobath or depth contour Together with the fishable habitat near the islands Tuvalu has a total 200 m depth contour of about 376 nautical miles The associated unexploited biomass of Tuvalus deep-water bottomfish on the distant seamounts is estimated at 421 mt while that for all of the Tuvalu EEZ is estimated at 639 mt The estimated MSY range for Tuvalus seamounts is 42-126 mtand the estimated MSY range for the entire Tuvalu EEZ is 64-192 mt Based on theseMSY estimates it has been calculated that this fishery could potentially support about 4 vessels fishing on the distant seamounts and about 2 additional vessels fishingaround Tuvalus islands
Contour maps of all of Tuvalus distant seamounts and 3-dimensional profiles of the smaller seamounts have been prepared and should prove useful to the Government of Tuvalu and to new entrants to the fishery
This final biological assessment by the Tuvalu Bottomfish Project concludes that Tuvalu does indeed have sufficient bottomfish habitat stock biomass and MSY to warrant the development of a modest commercial bottomfishing industry
4-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1
Figure 3-9 3-dimensional profile of Hera Bank
Hera Benk
3-11
Figure 3-10 Depth contour map of Takalo Bank
TAKALO BANK -1144
-1145 shy
-114
-114 0_49
- 115o0shy
-1151
-17961 -17960 -17959 -17958 -17957 -17956 -17955
Longitude (W)
3-12
Figure 3-1 1 3-dimensional profile of Takalo Bank
TekaIo Benk
C
Ic2
3-13
-1038
Figure 3-12 Depth contour map of Kosciusco Bank Area
KOSCIUSKO AREA
1042 + -1
-1046 -0
-1058-1054 -0 Cgt1 (j70
ci)i
-1067
-1071 L _ _j
- 1075 -- 1--
-1083 C __I
- 1087 fill 1 f
17937 17941 17945 17949 17953 17957 17961 17965 17969
Longitude (E) 3-14
-------
-----
Figure 3-13 Depth contour map of Bayonnaise Bank
BAYONNAISE BANK
-1158 ----- 190 -I I
I I
- --------- I
-1158 L ----- L-----GI
I -1108 ---- L- I -I I I
I I
K)I I
(f)-1188 K
-31198 -121 --------L--------L-------------shy
-J 0 K -1178 --- -- L ------- L----- -
1208------LI~p
00
-1218-- ------ L L __
II I I I I I I I
I-1228---------- -I
- L-- - 7 --- L II I II
I I
I I
-1238 -17989 -17979 -17969 -17959 -17949 -17939
Longitude (W)
3-15
Figure 3-14 Depth contour map of Macaw Bank Area
v-CAW BANK AREA
1060I -- I - L -I
I II
I I I-1060-----------shy
k I I II
oI
-o~1 - - - L
II
-1066ii~I amp )
-1065---- -
I I
-1067
I I I
-1069 -17926 -17925 -17924- - 7923 -17922 -17921 -17920 -17919 -17918
Longitude (W)
3-16
32 Research fishing
A total of 9981 kg of fish of 44 different species were caught Of this total 24 species were marketable with a total weight of 7661 kg (77) (Table 3-2) Three species Etelis carbunculus Etelis coruscans and Caranx lugubris made up the majorityof catch by weight The average CPUE of all species was 555 kgline-hour and 405 kgline-hour for marketable species These CPUE values are average by regionalstandards and probably represent the lower bound of a commercial CPUE range This is because research fishing is usually not as directed or intense as commercial fishing
33 Biomass and MSY estimation
Unexploited hiomass was calculated using a comparative approach based on data from 18 depletion surveys from similar regions in the South Pacific These surveys are outlined in Polovina and Shomura (1990) The estimated unexploited biomass (mtnmi) per unit area for seamount and insular areas was calculated (Table 3-3) usinghabitat estimates from the hydrographic surveys (Table 3-1) relative abundance estimates from the research fishing and the depletion survey information The results of applying 3 different fishery models (Beverton-Holt Gulland and Pauly) to data from the above regions in the South Pacific suggests the potential yield at MSY of stocks in the region is 10-30 of the unexploited biomass (Polovina and Shomura 1990)Based on these calculations the potential yield at MSY is 42-126 mt for seamounts in the Tuvaluan EEZ (Table 3-3) If atoll areas are included the MSY is estimated to be 64 to 192 mt
Using the range of landings from the research fishing (250-700 kgtrip) as a lowerbound of predicted commercial catch per trip the scale of the fishery can be estimated assuming 1 vessels catch = 1mt fishtrip 1 trip = 6 days fishing + 4 days in port for a total of 10 daystrip 1 vessel makes 3 tripsmonth the fishing season is 7 months Based on these assumptions 1 vessel could make 21 tripsseason By dividing the number of trips (lmttrip) into the MSY range (42-126 mt) it is estimated the seamount fishery could support 2 to 6 vessels If the 200m contour of the islands is included hypothetically the fishery could support 3 to 9 vessels (Alternatively if each vessel should catch 150 kg of bottomfish per fishing day for 90 fishing days per year then the mid-range estimate of the MSY on the seamounts could be caught byabout 6 vessels and the mid-range estimate of the MSY on both the seamounts and around the atolls could be caught with about 9 vessels) Care should be taken in applying an analysis of this type to the island contour as it assumes the bottomfishstocks are currently unexploited in those areas Furthermore the total allowable catch and thererore the number of fishing vessels will need to be restricted below the above estimates if financial considerations require the maintenance of high CPUEs
Finally it should be noted that the MSY estimates presented here are based on the results of research fishing trials and represent a preliminary estimate of yield after the commercial fishery reaches an equilibrium exploitation level As the commercial fisherydevelops catch and effort data should be collected to create a time series database which can be used to refine the MSY estimates
3-17 c
Table 3-2 Total catch by number and weight (marketable specieb only)
Species
A furcatus
A rutfans
A virescens
E carbunculus
E coruscans
E radiosus
P lausakari
P auricila
P filamentousus
P flavipinnus
P multidens
P zonatus
E areolatus
E chlorostigma
E fasciatus
E morrhua
Eseptemfasciatus
V out
V albomarginata
Other grouper
C ignobilis
C lugubris
S susmerili
S rivoliana
TOTAL
Weight(kq)
121
6352
1369
16827
9624
627
1336
1090
5200
3698
685
3366
160
519
20
3292
5389
263
150
356
452
13435
540
1640
76608
3-18
Percent of Total Weight ()
016
829
179
2196
1256
082
174
142
679
483
089
439
021
068
003
430
703
034
020
06
059
1754
070
214
10000
Table 3-3 Unexploited biomass and MSY range for Tuvalu
[Fishable Habitat Boo (mt) MSY Range(mt
Seamounts 421 42- 126
Islands 218 22 - 65
Total 639 64- 192
3-19
40 CONCLUSION
The hydrographic surveys on approximately 95 of Tuvalus fishable seamount and submerged bank habitat taken by the project staff on research and test fishing cruises show that Tuvalus distant seamounts have about 248 nautical miles of botomfish habitat as defined by the 200 m isobath or depth contour Together with the fishable habitat near the islands Tuvalu has a total 200 m depth contour of about 376 nautical miles The associated unexploited biomass of Tuvalus deep-water bottomfish on the distant seamounts is estimated at 421 mt while that for all of the Tuvalu EEZ is estimated at 639 mt The estimated MSY range for Tuvalus seamounts is 42-126 mtand the estimated MSY range for the entire Tuvalu EEZ is 64-192 mt Based on theseMSY estimates it has been calculated that this fishery could potentially support about 4 vessels fishing on the distant seamounts and about 2 additional vessels fishingaround Tuvalus islands
Contour maps of all of Tuvalus distant seamounts and 3-dimensional profiles of the smaller seamounts have been prepared and should prove useful to the Government of Tuvalu and to new entrants to the fishery
This final biological assessment by the Tuvalu Bottomfish Project concludes that Tuvalu does indeed have sufficient bottomfish habitat stock biomass and MSY to warrant the development of a modest commercial bottomfishing industry
4-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1
Figure 3-10 Depth contour map of Takalo Bank
TAKALO BANK -1144
-1145 shy
-114
-114 0_49
- 115o0shy
-1151
-17961 -17960 -17959 -17958 -17957 -17956 -17955
Longitude (W)
3-12
Figure 3-1 1 3-dimensional profile of Takalo Bank
TekaIo Benk
C
Ic2
3-13
-1038
Figure 3-12 Depth contour map of Kosciusco Bank Area
KOSCIUSKO AREA
1042 + -1
-1046 -0
-1058-1054 -0 Cgt1 (j70
ci)i
-1067
-1071 L _ _j
- 1075 -- 1--
-1083 C __I
- 1087 fill 1 f
17937 17941 17945 17949 17953 17957 17961 17965 17969
Longitude (E) 3-14
-------
-----
Figure 3-13 Depth contour map of Bayonnaise Bank
BAYONNAISE BANK
-1158 ----- 190 -I I
I I
- --------- I
-1158 L ----- L-----GI
I -1108 ---- L- I -I I I
I I
K)I I
(f)-1188 K
-31198 -121 --------L--------L-------------shy
-J 0 K -1178 --- -- L ------- L----- -
1208------LI~p
00
-1218-- ------ L L __
II I I I I I I I
I-1228---------- -I
- L-- - 7 --- L II I II
I I
I I
-1238 -17989 -17979 -17969 -17959 -17949 -17939
Longitude (W)
3-15
Figure 3-14 Depth contour map of Macaw Bank Area
v-CAW BANK AREA
1060I -- I - L -I
I II
I I I-1060-----------shy
k I I II
oI
-o~1 - - - L
II
-1066ii~I amp )
-1065---- -
I I
-1067
I I I
-1069 -17926 -17925 -17924- - 7923 -17922 -17921 -17920 -17919 -17918
Longitude (W)
3-16
32 Research fishing
A total of 9981 kg of fish of 44 different species were caught Of this total 24 species were marketable with a total weight of 7661 kg (77) (Table 3-2) Three species Etelis carbunculus Etelis coruscans and Caranx lugubris made up the majorityof catch by weight The average CPUE of all species was 555 kgline-hour and 405 kgline-hour for marketable species These CPUE values are average by regionalstandards and probably represent the lower bound of a commercial CPUE range This is because research fishing is usually not as directed or intense as commercial fishing
33 Biomass and MSY estimation
Unexploited hiomass was calculated using a comparative approach based on data from 18 depletion surveys from similar regions in the South Pacific These surveys are outlined in Polovina and Shomura (1990) The estimated unexploited biomass (mtnmi) per unit area for seamount and insular areas was calculated (Table 3-3) usinghabitat estimates from the hydrographic surveys (Table 3-1) relative abundance estimates from the research fishing and the depletion survey information The results of applying 3 different fishery models (Beverton-Holt Gulland and Pauly) to data from the above regions in the South Pacific suggests the potential yield at MSY of stocks in the region is 10-30 of the unexploited biomass (Polovina and Shomura 1990)Based on these calculations the potential yield at MSY is 42-126 mt for seamounts in the Tuvaluan EEZ (Table 3-3) If atoll areas are included the MSY is estimated to be 64 to 192 mt
Using the range of landings from the research fishing (250-700 kgtrip) as a lowerbound of predicted commercial catch per trip the scale of the fishery can be estimated assuming 1 vessels catch = 1mt fishtrip 1 trip = 6 days fishing + 4 days in port for a total of 10 daystrip 1 vessel makes 3 tripsmonth the fishing season is 7 months Based on these assumptions 1 vessel could make 21 tripsseason By dividing the number of trips (lmttrip) into the MSY range (42-126 mt) it is estimated the seamount fishery could support 2 to 6 vessels If the 200m contour of the islands is included hypothetically the fishery could support 3 to 9 vessels (Alternatively if each vessel should catch 150 kg of bottomfish per fishing day for 90 fishing days per year then the mid-range estimate of the MSY on the seamounts could be caught byabout 6 vessels and the mid-range estimate of the MSY on both the seamounts and around the atolls could be caught with about 9 vessels) Care should be taken in applying an analysis of this type to the island contour as it assumes the bottomfishstocks are currently unexploited in those areas Furthermore the total allowable catch and thererore the number of fishing vessels will need to be restricted below the above estimates if financial considerations require the maintenance of high CPUEs
Finally it should be noted that the MSY estimates presented here are based on the results of research fishing trials and represent a preliminary estimate of yield after the commercial fishery reaches an equilibrium exploitation level As the commercial fisherydevelops catch and effort data should be collected to create a time series database which can be used to refine the MSY estimates
3-17 c
Table 3-2 Total catch by number and weight (marketable specieb only)
Species
A furcatus
A rutfans
A virescens
E carbunculus
E coruscans
E radiosus
P lausakari
P auricila
P filamentousus
P flavipinnus
P multidens
P zonatus
E areolatus
E chlorostigma
E fasciatus
E morrhua
Eseptemfasciatus
V out
V albomarginata
Other grouper
C ignobilis
C lugubris
S susmerili
S rivoliana
TOTAL
Weight(kq)
121
6352
1369
16827
9624
627
1336
1090
5200
3698
685
3366
160
519
20
3292
5389
263
150
356
452
13435
540
1640
76608
3-18
Percent of Total Weight ()
016
829
179
2196
1256
082
174
142
679
483
089
439
021
068
003
430
703
034
020
06
059
1754
070
214
10000
Table 3-3 Unexploited biomass and MSY range for Tuvalu
[Fishable Habitat Boo (mt) MSY Range(mt
Seamounts 421 42- 126
Islands 218 22 - 65
Total 639 64- 192
3-19
40 CONCLUSION
The hydrographic surveys on approximately 95 of Tuvalus fishable seamount and submerged bank habitat taken by the project staff on research and test fishing cruises show that Tuvalus distant seamounts have about 248 nautical miles of botomfish habitat as defined by the 200 m isobath or depth contour Together with the fishable habitat near the islands Tuvalu has a total 200 m depth contour of about 376 nautical miles The associated unexploited biomass of Tuvalus deep-water bottomfish on the distant seamounts is estimated at 421 mt while that for all of the Tuvalu EEZ is estimated at 639 mt The estimated MSY range for Tuvalus seamounts is 42-126 mtand the estimated MSY range for the entire Tuvalu EEZ is 64-192 mt Based on theseMSY estimates it has been calculated that this fishery could potentially support about 4 vessels fishing on the distant seamounts and about 2 additional vessels fishingaround Tuvalus islands
Contour maps of all of Tuvalus distant seamounts and 3-dimensional profiles of the smaller seamounts have been prepared and should prove useful to the Government of Tuvalu and to new entrants to the fishery
This final biological assessment by the Tuvalu Bottomfish Project concludes that Tuvalu does indeed have sufficient bottomfish habitat stock biomass and MSY to warrant the development of a modest commercial bottomfishing industry
4-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1
Figure 3-1 1 3-dimensional profile of Takalo Bank
TekaIo Benk
C
Ic2
3-13
-1038
Figure 3-12 Depth contour map of Kosciusco Bank Area
KOSCIUSKO AREA
1042 + -1
-1046 -0
-1058-1054 -0 Cgt1 (j70
ci)i
-1067
-1071 L _ _j
- 1075 -- 1--
-1083 C __I
- 1087 fill 1 f
17937 17941 17945 17949 17953 17957 17961 17965 17969
Longitude (E) 3-14
-------
-----
Figure 3-13 Depth contour map of Bayonnaise Bank
BAYONNAISE BANK
-1158 ----- 190 -I I
I I
- --------- I
-1158 L ----- L-----GI
I -1108 ---- L- I -I I I
I I
K)I I
(f)-1188 K
-31198 -121 --------L--------L-------------shy
-J 0 K -1178 --- -- L ------- L----- -
1208------LI~p
00
-1218-- ------ L L __
II I I I I I I I
I-1228---------- -I
- L-- - 7 --- L II I II
I I
I I
-1238 -17989 -17979 -17969 -17959 -17949 -17939
Longitude (W)
3-15
Figure 3-14 Depth contour map of Macaw Bank Area
v-CAW BANK AREA
1060I -- I - L -I
I II
I I I-1060-----------shy
k I I II
oI
-o~1 - - - L
II
-1066ii~I amp )
-1065---- -
I I
-1067
I I I
-1069 -17926 -17925 -17924- - 7923 -17922 -17921 -17920 -17919 -17918
Longitude (W)
3-16
32 Research fishing
A total of 9981 kg of fish of 44 different species were caught Of this total 24 species were marketable with a total weight of 7661 kg (77) (Table 3-2) Three species Etelis carbunculus Etelis coruscans and Caranx lugubris made up the majorityof catch by weight The average CPUE of all species was 555 kgline-hour and 405 kgline-hour for marketable species These CPUE values are average by regionalstandards and probably represent the lower bound of a commercial CPUE range This is because research fishing is usually not as directed or intense as commercial fishing
33 Biomass and MSY estimation
Unexploited hiomass was calculated using a comparative approach based on data from 18 depletion surveys from similar regions in the South Pacific These surveys are outlined in Polovina and Shomura (1990) The estimated unexploited biomass (mtnmi) per unit area for seamount and insular areas was calculated (Table 3-3) usinghabitat estimates from the hydrographic surveys (Table 3-1) relative abundance estimates from the research fishing and the depletion survey information The results of applying 3 different fishery models (Beverton-Holt Gulland and Pauly) to data from the above regions in the South Pacific suggests the potential yield at MSY of stocks in the region is 10-30 of the unexploited biomass (Polovina and Shomura 1990)Based on these calculations the potential yield at MSY is 42-126 mt for seamounts in the Tuvaluan EEZ (Table 3-3) If atoll areas are included the MSY is estimated to be 64 to 192 mt
Using the range of landings from the research fishing (250-700 kgtrip) as a lowerbound of predicted commercial catch per trip the scale of the fishery can be estimated assuming 1 vessels catch = 1mt fishtrip 1 trip = 6 days fishing + 4 days in port for a total of 10 daystrip 1 vessel makes 3 tripsmonth the fishing season is 7 months Based on these assumptions 1 vessel could make 21 tripsseason By dividing the number of trips (lmttrip) into the MSY range (42-126 mt) it is estimated the seamount fishery could support 2 to 6 vessels If the 200m contour of the islands is included hypothetically the fishery could support 3 to 9 vessels (Alternatively if each vessel should catch 150 kg of bottomfish per fishing day for 90 fishing days per year then the mid-range estimate of the MSY on the seamounts could be caught byabout 6 vessels and the mid-range estimate of the MSY on both the seamounts and around the atolls could be caught with about 9 vessels) Care should be taken in applying an analysis of this type to the island contour as it assumes the bottomfishstocks are currently unexploited in those areas Furthermore the total allowable catch and thererore the number of fishing vessels will need to be restricted below the above estimates if financial considerations require the maintenance of high CPUEs
Finally it should be noted that the MSY estimates presented here are based on the results of research fishing trials and represent a preliminary estimate of yield after the commercial fishery reaches an equilibrium exploitation level As the commercial fisherydevelops catch and effort data should be collected to create a time series database which can be used to refine the MSY estimates
3-17 c
Table 3-2 Total catch by number and weight (marketable specieb only)
Species
A furcatus
A rutfans
A virescens
E carbunculus
E coruscans
E radiosus
P lausakari
P auricila
P filamentousus
P flavipinnus
P multidens
P zonatus
E areolatus
E chlorostigma
E fasciatus
E morrhua
Eseptemfasciatus
V out
V albomarginata
Other grouper
C ignobilis
C lugubris
S susmerili
S rivoliana
TOTAL
Weight(kq)
121
6352
1369
16827
9624
627
1336
1090
5200
3698
685
3366
160
519
20
3292
5389
263
150
356
452
13435
540
1640
76608
3-18
Percent of Total Weight ()
016
829
179
2196
1256
082
174
142
679
483
089
439
021
068
003
430
703
034
020
06
059
1754
070
214
10000
Table 3-3 Unexploited biomass and MSY range for Tuvalu
[Fishable Habitat Boo (mt) MSY Range(mt
Seamounts 421 42- 126
Islands 218 22 - 65
Total 639 64- 192
3-19
40 CONCLUSION
The hydrographic surveys on approximately 95 of Tuvalus fishable seamount and submerged bank habitat taken by the project staff on research and test fishing cruises show that Tuvalus distant seamounts have about 248 nautical miles of botomfish habitat as defined by the 200 m isobath or depth contour Together with the fishable habitat near the islands Tuvalu has a total 200 m depth contour of about 376 nautical miles The associated unexploited biomass of Tuvalus deep-water bottomfish on the distant seamounts is estimated at 421 mt while that for all of the Tuvalu EEZ is estimated at 639 mt The estimated MSY range for Tuvalus seamounts is 42-126 mtand the estimated MSY range for the entire Tuvalu EEZ is 64-192 mt Based on theseMSY estimates it has been calculated that this fishery could potentially support about 4 vessels fishing on the distant seamounts and about 2 additional vessels fishingaround Tuvalus islands
Contour maps of all of Tuvalus distant seamounts and 3-dimensional profiles of the smaller seamounts have been prepared and should prove useful to the Government of Tuvalu and to new entrants to the fishery
This final biological assessment by the Tuvalu Bottomfish Project concludes that Tuvalu does indeed have sufficient bottomfish habitat stock biomass and MSY to warrant the development of a modest commercial bottomfishing industry
4-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1
-1038
Figure 3-12 Depth contour map of Kosciusco Bank Area
KOSCIUSKO AREA
1042 + -1
-1046 -0
-1058-1054 -0 Cgt1 (j70
ci)i
-1067
-1071 L _ _j
- 1075 -- 1--
-1083 C __I
- 1087 fill 1 f
17937 17941 17945 17949 17953 17957 17961 17965 17969
Longitude (E) 3-14
-------
-----
Figure 3-13 Depth contour map of Bayonnaise Bank
BAYONNAISE BANK
-1158 ----- 190 -I I
I I
- --------- I
-1158 L ----- L-----GI
I -1108 ---- L- I -I I I
I I
K)I I
(f)-1188 K
-31198 -121 --------L--------L-------------shy
-J 0 K -1178 --- -- L ------- L----- -
1208------LI~p
00
-1218-- ------ L L __
II I I I I I I I
I-1228---------- -I
- L-- - 7 --- L II I II
I I
I I
-1238 -17989 -17979 -17969 -17959 -17949 -17939
Longitude (W)
3-15
Figure 3-14 Depth contour map of Macaw Bank Area
v-CAW BANK AREA
1060I -- I - L -I
I II
I I I-1060-----------shy
k I I II
oI
-o~1 - - - L
II
-1066ii~I amp )
-1065---- -
I I
-1067
I I I
-1069 -17926 -17925 -17924- - 7923 -17922 -17921 -17920 -17919 -17918
Longitude (W)
3-16
32 Research fishing
A total of 9981 kg of fish of 44 different species were caught Of this total 24 species were marketable with a total weight of 7661 kg (77) (Table 3-2) Three species Etelis carbunculus Etelis coruscans and Caranx lugubris made up the majorityof catch by weight The average CPUE of all species was 555 kgline-hour and 405 kgline-hour for marketable species These CPUE values are average by regionalstandards and probably represent the lower bound of a commercial CPUE range This is because research fishing is usually not as directed or intense as commercial fishing
33 Biomass and MSY estimation
Unexploited hiomass was calculated using a comparative approach based on data from 18 depletion surveys from similar regions in the South Pacific These surveys are outlined in Polovina and Shomura (1990) The estimated unexploited biomass (mtnmi) per unit area for seamount and insular areas was calculated (Table 3-3) usinghabitat estimates from the hydrographic surveys (Table 3-1) relative abundance estimates from the research fishing and the depletion survey information The results of applying 3 different fishery models (Beverton-Holt Gulland and Pauly) to data from the above regions in the South Pacific suggests the potential yield at MSY of stocks in the region is 10-30 of the unexploited biomass (Polovina and Shomura 1990)Based on these calculations the potential yield at MSY is 42-126 mt for seamounts in the Tuvaluan EEZ (Table 3-3) If atoll areas are included the MSY is estimated to be 64 to 192 mt
Using the range of landings from the research fishing (250-700 kgtrip) as a lowerbound of predicted commercial catch per trip the scale of the fishery can be estimated assuming 1 vessels catch = 1mt fishtrip 1 trip = 6 days fishing + 4 days in port for a total of 10 daystrip 1 vessel makes 3 tripsmonth the fishing season is 7 months Based on these assumptions 1 vessel could make 21 tripsseason By dividing the number of trips (lmttrip) into the MSY range (42-126 mt) it is estimated the seamount fishery could support 2 to 6 vessels If the 200m contour of the islands is included hypothetically the fishery could support 3 to 9 vessels (Alternatively if each vessel should catch 150 kg of bottomfish per fishing day for 90 fishing days per year then the mid-range estimate of the MSY on the seamounts could be caught byabout 6 vessels and the mid-range estimate of the MSY on both the seamounts and around the atolls could be caught with about 9 vessels) Care should be taken in applying an analysis of this type to the island contour as it assumes the bottomfishstocks are currently unexploited in those areas Furthermore the total allowable catch and thererore the number of fishing vessels will need to be restricted below the above estimates if financial considerations require the maintenance of high CPUEs
Finally it should be noted that the MSY estimates presented here are based on the results of research fishing trials and represent a preliminary estimate of yield after the commercial fishery reaches an equilibrium exploitation level As the commercial fisherydevelops catch and effort data should be collected to create a time series database which can be used to refine the MSY estimates
3-17 c
Table 3-2 Total catch by number and weight (marketable specieb only)
Species
A furcatus
A rutfans
A virescens
E carbunculus
E coruscans
E radiosus
P lausakari
P auricila
P filamentousus
P flavipinnus
P multidens
P zonatus
E areolatus
E chlorostigma
E fasciatus
E morrhua
Eseptemfasciatus
V out
V albomarginata
Other grouper
C ignobilis
C lugubris
S susmerili
S rivoliana
TOTAL
Weight(kq)
121
6352
1369
16827
9624
627
1336
1090
5200
3698
685
3366
160
519
20
3292
5389
263
150
356
452
13435
540
1640
76608
3-18
Percent of Total Weight ()
016
829
179
2196
1256
082
174
142
679
483
089
439
021
068
003
430
703
034
020
06
059
1754
070
214
10000
Table 3-3 Unexploited biomass and MSY range for Tuvalu
[Fishable Habitat Boo (mt) MSY Range(mt
Seamounts 421 42- 126
Islands 218 22 - 65
Total 639 64- 192
3-19
40 CONCLUSION
The hydrographic surveys on approximately 95 of Tuvalus fishable seamount and submerged bank habitat taken by the project staff on research and test fishing cruises show that Tuvalus distant seamounts have about 248 nautical miles of botomfish habitat as defined by the 200 m isobath or depth contour Together with the fishable habitat near the islands Tuvalu has a total 200 m depth contour of about 376 nautical miles The associated unexploited biomass of Tuvalus deep-water bottomfish on the distant seamounts is estimated at 421 mt while that for all of the Tuvalu EEZ is estimated at 639 mt The estimated MSY range for Tuvalus seamounts is 42-126 mtand the estimated MSY range for the entire Tuvalu EEZ is 64-192 mt Based on theseMSY estimates it has been calculated that this fishery could potentially support about 4 vessels fishing on the distant seamounts and about 2 additional vessels fishingaround Tuvalus islands
Contour maps of all of Tuvalus distant seamounts and 3-dimensional profiles of the smaller seamounts have been prepared and should prove useful to the Government of Tuvalu and to new entrants to the fishery
This final biological assessment by the Tuvalu Bottomfish Project concludes that Tuvalu does indeed have sufficient bottomfish habitat stock biomass and MSY to warrant the development of a modest commercial bottomfishing industry
4-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1
-------
-----
Figure 3-13 Depth contour map of Bayonnaise Bank
BAYONNAISE BANK
-1158 ----- 190 -I I
I I
- --------- I
-1158 L ----- L-----GI
I -1108 ---- L- I -I I I
I I
K)I I
(f)-1188 K
-31198 -121 --------L--------L-------------shy
-J 0 K -1178 --- -- L ------- L----- -
1208------LI~p
00
-1218-- ------ L L __
II I I I I I I I
I-1228---------- -I
- L-- - 7 --- L II I II
I I
I I
-1238 -17989 -17979 -17969 -17959 -17949 -17939
Longitude (W)
3-15
Figure 3-14 Depth contour map of Macaw Bank Area
v-CAW BANK AREA
1060I -- I - L -I
I II
I I I-1060-----------shy
k I I II
oI
-o~1 - - - L
II
-1066ii~I amp )
-1065---- -
I I
-1067
I I I
-1069 -17926 -17925 -17924- - 7923 -17922 -17921 -17920 -17919 -17918
Longitude (W)
3-16
32 Research fishing
A total of 9981 kg of fish of 44 different species were caught Of this total 24 species were marketable with a total weight of 7661 kg (77) (Table 3-2) Three species Etelis carbunculus Etelis coruscans and Caranx lugubris made up the majorityof catch by weight The average CPUE of all species was 555 kgline-hour and 405 kgline-hour for marketable species These CPUE values are average by regionalstandards and probably represent the lower bound of a commercial CPUE range This is because research fishing is usually not as directed or intense as commercial fishing
33 Biomass and MSY estimation
Unexploited hiomass was calculated using a comparative approach based on data from 18 depletion surveys from similar regions in the South Pacific These surveys are outlined in Polovina and Shomura (1990) The estimated unexploited biomass (mtnmi) per unit area for seamount and insular areas was calculated (Table 3-3) usinghabitat estimates from the hydrographic surveys (Table 3-1) relative abundance estimates from the research fishing and the depletion survey information The results of applying 3 different fishery models (Beverton-Holt Gulland and Pauly) to data from the above regions in the South Pacific suggests the potential yield at MSY of stocks in the region is 10-30 of the unexploited biomass (Polovina and Shomura 1990)Based on these calculations the potential yield at MSY is 42-126 mt for seamounts in the Tuvaluan EEZ (Table 3-3) If atoll areas are included the MSY is estimated to be 64 to 192 mt
Using the range of landings from the research fishing (250-700 kgtrip) as a lowerbound of predicted commercial catch per trip the scale of the fishery can be estimated assuming 1 vessels catch = 1mt fishtrip 1 trip = 6 days fishing + 4 days in port for a total of 10 daystrip 1 vessel makes 3 tripsmonth the fishing season is 7 months Based on these assumptions 1 vessel could make 21 tripsseason By dividing the number of trips (lmttrip) into the MSY range (42-126 mt) it is estimated the seamount fishery could support 2 to 6 vessels If the 200m contour of the islands is included hypothetically the fishery could support 3 to 9 vessels (Alternatively if each vessel should catch 150 kg of bottomfish per fishing day for 90 fishing days per year then the mid-range estimate of the MSY on the seamounts could be caught byabout 6 vessels and the mid-range estimate of the MSY on both the seamounts and around the atolls could be caught with about 9 vessels) Care should be taken in applying an analysis of this type to the island contour as it assumes the bottomfishstocks are currently unexploited in those areas Furthermore the total allowable catch and thererore the number of fishing vessels will need to be restricted below the above estimates if financial considerations require the maintenance of high CPUEs
Finally it should be noted that the MSY estimates presented here are based on the results of research fishing trials and represent a preliminary estimate of yield after the commercial fishery reaches an equilibrium exploitation level As the commercial fisherydevelops catch and effort data should be collected to create a time series database which can be used to refine the MSY estimates
3-17 c
Table 3-2 Total catch by number and weight (marketable specieb only)
Species
A furcatus
A rutfans
A virescens
E carbunculus
E coruscans
E radiosus
P lausakari
P auricila
P filamentousus
P flavipinnus
P multidens
P zonatus
E areolatus
E chlorostigma
E fasciatus
E morrhua
Eseptemfasciatus
V out
V albomarginata
Other grouper
C ignobilis
C lugubris
S susmerili
S rivoliana
TOTAL
Weight(kq)
121
6352
1369
16827
9624
627
1336
1090
5200
3698
685
3366
160
519
20
3292
5389
263
150
356
452
13435
540
1640
76608
3-18
Percent of Total Weight ()
016
829
179
2196
1256
082
174
142
679
483
089
439
021
068
003
430
703
034
020
06
059
1754
070
214
10000
Table 3-3 Unexploited biomass and MSY range for Tuvalu
[Fishable Habitat Boo (mt) MSY Range(mt
Seamounts 421 42- 126
Islands 218 22 - 65
Total 639 64- 192
3-19
40 CONCLUSION
The hydrographic surveys on approximately 95 of Tuvalus fishable seamount and submerged bank habitat taken by the project staff on research and test fishing cruises show that Tuvalus distant seamounts have about 248 nautical miles of botomfish habitat as defined by the 200 m isobath or depth contour Together with the fishable habitat near the islands Tuvalu has a total 200 m depth contour of about 376 nautical miles The associated unexploited biomass of Tuvalus deep-water bottomfish on the distant seamounts is estimated at 421 mt while that for all of the Tuvalu EEZ is estimated at 639 mt The estimated MSY range for Tuvalus seamounts is 42-126 mtand the estimated MSY range for the entire Tuvalu EEZ is 64-192 mt Based on theseMSY estimates it has been calculated that this fishery could potentially support about 4 vessels fishing on the distant seamounts and about 2 additional vessels fishingaround Tuvalus islands
Contour maps of all of Tuvalus distant seamounts and 3-dimensional profiles of the smaller seamounts have been prepared and should prove useful to the Government of Tuvalu and to new entrants to the fishery
This final biological assessment by the Tuvalu Bottomfish Project concludes that Tuvalu does indeed have sufficient bottomfish habitat stock biomass and MSY to warrant the development of a modest commercial bottomfishing industry
4-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1
Figure 3-14 Depth contour map of Macaw Bank Area
v-CAW BANK AREA
1060I -- I - L -I
I II
I I I-1060-----------shy
k I I II
oI
-o~1 - - - L
II
-1066ii~I amp )
-1065---- -
I I
-1067
I I I
-1069 -17926 -17925 -17924- - 7923 -17922 -17921 -17920 -17919 -17918
Longitude (W)
3-16
32 Research fishing
A total of 9981 kg of fish of 44 different species were caught Of this total 24 species were marketable with a total weight of 7661 kg (77) (Table 3-2) Three species Etelis carbunculus Etelis coruscans and Caranx lugubris made up the majorityof catch by weight The average CPUE of all species was 555 kgline-hour and 405 kgline-hour for marketable species These CPUE values are average by regionalstandards and probably represent the lower bound of a commercial CPUE range This is because research fishing is usually not as directed or intense as commercial fishing
33 Biomass and MSY estimation
Unexploited hiomass was calculated using a comparative approach based on data from 18 depletion surveys from similar regions in the South Pacific These surveys are outlined in Polovina and Shomura (1990) The estimated unexploited biomass (mtnmi) per unit area for seamount and insular areas was calculated (Table 3-3) usinghabitat estimates from the hydrographic surveys (Table 3-1) relative abundance estimates from the research fishing and the depletion survey information The results of applying 3 different fishery models (Beverton-Holt Gulland and Pauly) to data from the above regions in the South Pacific suggests the potential yield at MSY of stocks in the region is 10-30 of the unexploited biomass (Polovina and Shomura 1990)Based on these calculations the potential yield at MSY is 42-126 mt for seamounts in the Tuvaluan EEZ (Table 3-3) If atoll areas are included the MSY is estimated to be 64 to 192 mt
Using the range of landings from the research fishing (250-700 kgtrip) as a lowerbound of predicted commercial catch per trip the scale of the fishery can be estimated assuming 1 vessels catch = 1mt fishtrip 1 trip = 6 days fishing + 4 days in port for a total of 10 daystrip 1 vessel makes 3 tripsmonth the fishing season is 7 months Based on these assumptions 1 vessel could make 21 tripsseason By dividing the number of trips (lmttrip) into the MSY range (42-126 mt) it is estimated the seamount fishery could support 2 to 6 vessels If the 200m contour of the islands is included hypothetically the fishery could support 3 to 9 vessels (Alternatively if each vessel should catch 150 kg of bottomfish per fishing day for 90 fishing days per year then the mid-range estimate of the MSY on the seamounts could be caught byabout 6 vessels and the mid-range estimate of the MSY on both the seamounts and around the atolls could be caught with about 9 vessels) Care should be taken in applying an analysis of this type to the island contour as it assumes the bottomfishstocks are currently unexploited in those areas Furthermore the total allowable catch and thererore the number of fishing vessels will need to be restricted below the above estimates if financial considerations require the maintenance of high CPUEs
Finally it should be noted that the MSY estimates presented here are based on the results of research fishing trials and represent a preliminary estimate of yield after the commercial fishery reaches an equilibrium exploitation level As the commercial fisherydevelops catch and effort data should be collected to create a time series database which can be used to refine the MSY estimates
3-17 c
Table 3-2 Total catch by number and weight (marketable specieb only)
Species
A furcatus
A rutfans
A virescens
E carbunculus
E coruscans
E radiosus
P lausakari
P auricila
P filamentousus
P flavipinnus
P multidens
P zonatus
E areolatus
E chlorostigma
E fasciatus
E morrhua
Eseptemfasciatus
V out
V albomarginata
Other grouper
C ignobilis
C lugubris
S susmerili
S rivoliana
TOTAL
Weight(kq)
121
6352
1369
16827
9624
627
1336
1090
5200
3698
685
3366
160
519
20
3292
5389
263
150
356
452
13435
540
1640
76608
3-18
Percent of Total Weight ()
016
829
179
2196
1256
082
174
142
679
483
089
439
021
068
003
430
703
034
020
06
059
1754
070
214
10000
Table 3-3 Unexploited biomass and MSY range for Tuvalu
[Fishable Habitat Boo (mt) MSY Range(mt
Seamounts 421 42- 126
Islands 218 22 - 65
Total 639 64- 192
3-19
40 CONCLUSION
The hydrographic surveys on approximately 95 of Tuvalus fishable seamount and submerged bank habitat taken by the project staff on research and test fishing cruises show that Tuvalus distant seamounts have about 248 nautical miles of botomfish habitat as defined by the 200 m isobath or depth contour Together with the fishable habitat near the islands Tuvalu has a total 200 m depth contour of about 376 nautical miles The associated unexploited biomass of Tuvalus deep-water bottomfish on the distant seamounts is estimated at 421 mt while that for all of the Tuvalu EEZ is estimated at 639 mt The estimated MSY range for Tuvalus seamounts is 42-126 mtand the estimated MSY range for the entire Tuvalu EEZ is 64-192 mt Based on theseMSY estimates it has been calculated that this fishery could potentially support about 4 vessels fishing on the distant seamounts and about 2 additional vessels fishingaround Tuvalus islands
Contour maps of all of Tuvalus distant seamounts and 3-dimensional profiles of the smaller seamounts have been prepared and should prove useful to the Government of Tuvalu and to new entrants to the fishery
This final biological assessment by the Tuvalu Bottomfish Project concludes that Tuvalu does indeed have sufficient bottomfish habitat stock biomass and MSY to warrant the development of a modest commercial bottomfishing industry
4-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1
32 Research fishing
A total of 9981 kg of fish of 44 different species were caught Of this total 24 species were marketable with a total weight of 7661 kg (77) (Table 3-2) Three species Etelis carbunculus Etelis coruscans and Caranx lugubris made up the majorityof catch by weight The average CPUE of all species was 555 kgline-hour and 405 kgline-hour for marketable species These CPUE values are average by regionalstandards and probably represent the lower bound of a commercial CPUE range This is because research fishing is usually not as directed or intense as commercial fishing
33 Biomass and MSY estimation
Unexploited hiomass was calculated using a comparative approach based on data from 18 depletion surveys from similar regions in the South Pacific These surveys are outlined in Polovina and Shomura (1990) The estimated unexploited biomass (mtnmi) per unit area for seamount and insular areas was calculated (Table 3-3) usinghabitat estimates from the hydrographic surveys (Table 3-1) relative abundance estimates from the research fishing and the depletion survey information The results of applying 3 different fishery models (Beverton-Holt Gulland and Pauly) to data from the above regions in the South Pacific suggests the potential yield at MSY of stocks in the region is 10-30 of the unexploited biomass (Polovina and Shomura 1990)Based on these calculations the potential yield at MSY is 42-126 mt for seamounts in the Tuvaluan EEZ (Table 3-3) If atoll areas are included the MSY is estimated to be 64 to 192 mt
Using the range of landings from the research fishing (250-700 kgtrip) as a lowerbound of predicted commercial catch per trip the scale of the fishery can be estimated assuming 1 vessels catch = 1mt fishtrip 1 trip = 6 days fishing + 4 days in port for a total of 10 daystrip 1 vessel makes 3 tripsmonth the fishing season is 7 months Based on these assumptions 1 vessel could make 21 tripsseason By dividing the number of trips (lmttrip) into the MSY range (42-126 mt) it is estimated the seamount fishery could support 2 to 6 vessels If the 200m contour of the islands is included hypothetically the fishery could support 3 to 9 vessels (Alternatively if each vessel should catch 150 kg of bottomfish per fishing day for 90 fishing days per year then the mid-range estimate of the MSY on the seamounts could be caught byabout 6 vessels and the mid-range estimate of the MSY on both the seamounts and around the atolls could be caught with about 9 vessels) Care should be taken in applying an analysis of this type to the island contour as it assumes the bottomfishstocks are currently unexploited in those areas Furthermore the total allowable catch and thererore the number of fishing vessels will need to be restricted below the above estimates if financial considerations require the maintenance of high CPUEs
Finally it should be noted that the MSY estimates presented here are based on the results of research fishing trials and represent a preliminary estimate of yield after the commercial fishery reaches an equilibrium exploitation level As the commercial fisherydevelops catch and effort data should be collected to create a time series database which can be used to refine the MSY estimates
3-17 c
Table 3-2 Total catch by number and weight (marketable specieb only)
Species
A furcatus
A rutfans
A virescens
E carbunculus
E coruscans
E radiosus
P lausakari
P auricila
P filamentousus
P flavipinnus
P multidens
P zonatus
E areolatus
E chlorostigma
E fasciatus
E morrhua
Eseptemfasciatus
V out
V albomarginata
Other grouper
C ignobilis
C lugubris
S susmerili
S rivoliana
TOTAL
Weight(kq)
121
6352
1369
16827
9624
627
1336
1090
5200
3698
685
3366
160
519
20
3292
5389
263
150
356
452
13435
540
1640
76608
3-18
Percent of Total Weight ()
016
829
179
2196
1256
082
174
142
679
483
089
439
021
068
003
430
703
034
020
06
059
1754
070
214
10000
Table 3-3 Unexploited biomass and MSY range for Tuvalu
[Fishable Habitat Boo (mt) MSY Range(mt
Seamounts 421 42- 126
Islands 218 22 - 65
Total 639 64- 192
3-19
40 CONCLUSION
The hydrographic surveys on approximately 95 of Tuvalus fishable seamount and submerged bank habitat taken by the project staff on research and test fishing cruises show that Tuvalus distant seamounts have about 248 nautical miles of botomfish habitat as defined by the 200 m isobath or depth contour Together with the fishable habitat near the islands Tuvalu has a total 200 m depth contour of about 376 nautical miles The associated unexploited biomass of Tuvalus deep-water bottomfish on the distant seamounts is estimated at 421 mt while that for all of the Tuvalu EEZ is estimated at 639 mt The estimated MSY range for Tuvalus seamounts is 42-126 mtand the estimated MSY range for the entire Tuvalu EEZ is 64-192 mt Based on theseMSY estimates it has been calculated that this fishery could potentially support about 4 vessels fishing on the distant seamounts and about 2 additional vessels fishingaround Tuvalus islands
Contour maps of all of Tuvalus distant seamounts and 3-dimensional profiles of the smaller seamounts have been prepared and should prove useful to the Government of Tuvalu and to new entrants to the fishery
This final biological assessment by the Tuvalu Bottomfish Project concludes that Tuvalu does indeed have sufficient bottomfish habitat stock biomass and MSY to warrant the development of a modest commercial bottomfishing industry
4-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1
Table 3-2 Total catch by number and weight (marketable specieb only)
Species
A furcatus
A rutfans
A virescens
E carbunculus
E coruscans
E radiosus
P lausakari
P auricila
P filamentousus
P flavipinnus
P multidens
P zonatus
E areolatus
E chlorostigma
E fasciatus
E morrhua
Eseptemfasciatus
V out
V albomarginata
Other grouper
C ignobilis
C lugubris
S susmerili
S rivoliana
TOTAL
Weight(kq)
121
6352
1369
16827
9624
627
1336
1090
5200
3698
685
3366
160
519
20
3292
5389
263
150
356
452
13435
540
1640
76608
3-18
Percent of Total Weight ()
016
829
179
2196
1256
082
174
142
679
483
089
439
021
068
003
430
703
034
020
06
059
1754
070
214
10000
Table 3-3 Unexploited biomass and MSY range for Tuvalu
[Fishable Habitat Boo (mt) MSY Range(mt
Seamounts 421 42- 126
Islands 218 22 - 65
Total 639 64- 192
3-19
40 CONCLUSION
The hydrographic surveys on approximately 95 of Tuvalus fishable seamount and submerged bank habitat taken by the project staff on research and test fishing cruises show that Tuvalus distant seamounts have about 248 nautical miles of botomfish habitat as defined by the 200 m isobath or depth contour Together with the fishable habitat near the islands Tuvalu has a total 200 m depth contour of about 376 nautical miles The associated unexploited biomass of Tuvalus deep-water bottomfish on the distant seamounts is estimated at 421 mt while that for all of the Tuvalu EEZ is estimated at 639 mt The estimated MSY range for Tuvalus seamounts is 42-126 mtand the estimated MSY range for the entire Tuvalu EEZ is 64-192 mt Based on theseMSY estimates it has been calculated that this fishery could potentially support about 4 vessels fishing on the distant seamounts and about 2 additional vessels fishingaround Tuvalus islands
Contour maps of all of Tuvalus distant seamounts and 3-dimensional profiles of the smaller seamounts have been prepared and should prove useful to the Government of Tuvalu and to new entrants to the fishery
This final biological assessment by the Tuvalu Bottomfish Project concludes that Tuvalu does indeed have sufficient bottomfish habitat stock biomass and MSY to warrant the development of a modest commercial bottomfishing industry
4-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1
Table 3-3 Unexploited biomass and MSY range for Tuvalu
[Fishable Habitat Boo (mt) MSY Range(mt
Seamounts 421 42- 126
Islands 218 22 - 65
Total 639 64- 192
3-19
40 CONCLUSION
The hydrographic surveys on approximately 95 of Tuvalus fishable seamount and submerged bank habitat taken by the project staff on research and test fishing cruises show that Tuvalus distant seamounts have about 248 nautical miles of botomfish habitat as defined by the 200 m isobath or depth contour Together with the fishable habitat near the islands Tuvalu has a total 200 m depth contour of about 376 nautical miles The associated unexploited biomass of Tuvalus deep-water bottomfish on the distant seamounts is estimated at 421 mt while that for all of the Tuvalu EEZ is estimated at 639 mt The estimated MSY range for Tuvalus seamounts is 42-126 mtand the estimated MSY range for the entire Tuvalu EEZ is 64-192 mt Based on theseMSY estimates it has been calculated that this fishery could potentially support about 4 vessels fishing on the distant seamounts and about 2 additional vessels fishingaround Tuvalus islands
Contour maps of all of Tuvalus distant seamounts and 3-dimensional profiles of the smaller seamounts have been prepared and should prove useful to the Government of Tuvalu and to new entrants to the fishery
This final biological assessment by the Tuvalu Bottomfish Project concludes that Tuvalu does indeed have sufficient bottomfish habitat stock biomass and MSY to warrant the development of a modest commercial bottomfishing industry
4-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1
40 CONCLUSION
The hydrographic surveys on approximately 95 of Tuvalus fishable seamount and submerged bank habitat taken by the project staff on research and test fishing cruises show that Tuvalus distant seamounts have about 248 nautical miles of botomfish habitat as defined by the 200 m isobath or depth contour Together with the fishable habitat near the islands Tuvalu has a total 200 m depth contour of about 376 nautical miles The associated unexploited biomass of Tuvalus deep-water bottomfish on the distant seamounts is estimated at 421 mt while that for all of the Tuvalu EEZ is estimated at 639 mt The estimated MSY range for Tuvalus seamounts is 42-126 mtand the estimated MSY range for the entire Tuvalu EEZ is 64-192 mt Based on theseMSY estimates it has been calculated that this fishery could potentially support about 4 vessels fishing on the distant seamounts and about 2 additional vessels fishingaround Tuvalus islands
Contour maps of all of Tuvalus distant seamounts and 3-dimensional profiles of the smaller seamounts have been prepared and should prove useful to the Government of Tuvalu and to new entrants to the fishery
This final biological assessment by the Tuvalu Bottomfish Project concludes that Tuvalu does indeed have sufficient bottomfish habitat stock biomass and MSY to warrant the development of a modest commercial bottomfishing industry
4-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1
50 REFERENCES
Dalzell P and Preston GL 1991 Deep reef fishery resources of the South PacificSouth Pacific Commission Inshore Fisheries Research Project Tech Doc No 2 301p
Polovina JJ and Shomura RS 1990 USAID and NMFS workshop on tropical fish stock assessment 5-26 July 1989 Honolulu Hawaii NOAA Tech Mem NOAA-TMshyNMFS-WSFSC-148 14 4p
5-1