Transcript Slide 1

2007 ICCAT SCRS
Executive Summay for
Atlantic Bigeye Tuna
Biology
Distribution : 50N-45S, not in Mediterranean
Swimming Behavior : extensive vertical movement,
deeper during daytime, shallower at night.
Spawning : tropical-subtropical, mature at age 3
Nursery : Gulf of Guinea
Prey : fish, mollusk, crustacean
Growth (relatively fast) : Age 3 (105 cm), Age 5
(140cm), Age 7 (163cm)
Schooling behavior : Juveniles are mixed with
yellowfin and skipjack
Natural mortality : estimated by tagging data
Stock structure : Atlantic wide
BET
Catch
Fisheries : LL(45-50kg), North BB(20-30kg), PS+Trop BB(3-4kg)
LL : Japan, Chinese Taipei, China, Philippines
PS : EC-Spain+France, Ghana, Venezuela (in association with FADs)
Figure 1.
Catch by Gear
140000
Species
compositio
n
data is
important
& improved
for Ghana
Other surf.
120000
100000
Longline
80000
Bait boat
60000
40000
2006 catch
is 65,000 t
20000
Year
2005
2000
1995
1990
1985
1980
1975
1970
1965
1960
1955
0
1950
Catch (t)
Purse seine
BET
Catch
Distribution
Figure 2.
Geographic distribution of bigeye catches for most recent years (2002-2005) by major tuna fishery.
BET Catch
Unreported Catches
30000
25000
Catch (t)
20000
15000
NEI (Longline)
10000
5000
2005
2000
1995
1990
1985
1980
1975
1970
1965
1960
1955
1950
0
year
Figure 3.
Unreported catches estimated from trade statistics.
BET abundance Indices
Figure 4-1.
Abundunce indices in number
2.5
Japan LL
Chinese Taipei LL
2.0
US LL
Scaled CPUE
Brazil LL
1.5
1.0
0.5
0.0
1960
1965
1970
1975
1980
1985
Year
1990
1995
2000
2005
BETabundance Indices
Figure 4-2.
Abundunce indices in weight
3.5
Japan LL
Chinese Taipei LL
US LL
Brazil LL
Azores BB
ESP & FRA PS
3.0
Scaled CPUE
2.5
New
CPUE
2.0
1.5
1.0
0.5
0.0
1960
1965
1970
1975
1980 1985
Year
1990
1995
2000
2005
BET Abundance Indices
Juvenile BET FAD Standardized CPUE
12
10
8
6
4
2
0
1991
1993
1995
1997
1999
year
2001
2003
2005
BET Assessment Models
Several types of assessment models including production
models, VPA and a statistical integrated model (Multifan-CL)
were applied to the available data. There was a range of stock
status evaluations from the various model formulations applied,
not all of which were judged to be equally likely.
Consistent with previous assessments, the results from nonequilibrium
production models are used to provide our best characterization of the
status of the resource. The current MSY estimated using two types of
production models was about 90,000 t and 93,000 t, although
uncertainty in the estimates would broaden the range. In addition,
these estimates reflect the current relative mixture of fisheries that
capture small or large bigeye; MSY can change considerably with
changes in the relative fishing effort exerted by surface and longline
fisheries.
BETModel Results
Estimated MSY : 90,000 – 93,000 t
2.5
B/Bmsy
F/Fmsy
Figure 5.
2.0
Ratio
1.5
1.0
0.5
0.0
1950 1955 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005
Year
Trajectories of B-ratio and F-ratio obtained from ASPIC base case run.
BETModel Results
MFCL run results. Selectivity curve for each decade (left). MSY estimates.
1960s
1970s
MSY estimates
1980s
1990s
2000s
BET Model Results
Figure 6.
Estimated range of stock status results (B/BMSY and F/FMSY) in 2005
which characterizes our uncertainty in stock status (right panel). Time
series of B/BMSY and F/FMSY from 1950 to 2005 (left panel).
BET Outlook
85K
Figure 7.
Stock projections by ASPIC model assuming a catch of 71,000 t in
2006 and varying levels of the constant catch thereafter.
BET Effects of current regulations
Multi-year Conservation and Management
Program Rec[04-01] sets :
 TAC for Major Countries at 90,000 t.
 A specific limit for the number of vessel for several
country/entity.
 Closure for surface fisheries in the area 0˚-5˚N, 10˚
W-20˚W during November (in the Gulf of Guinea).
The closure is much smaller in time and space
compared to the previous one. Need to expand it if
we want to be more effective.
BET Trend in catches of small BET
Percentage and number of BET less than 3.2 Kg.
90%
80%
% 4th Q
% Total
% 1st Q
Total number
20
15
50%
40%
10
30%
20%
5
Figure 8.
10%
0%
0
19
75
19
77
19
79
19
81
19
83
19
85
19
87
19
89
19
91
19
93
19
95
19
97
19
99
20
01
20
03
20
05
% of less 3.2kg
60%
Number of catch (million)
70%
Year
BET
Management Recommendation
 Projection indicates that catches of 85,000 t or less will
permit the stock to rebuild in the future.
 However, if the entire catch limit set under 04-01 were
to take and others stayed at recent level, the total
catch could exceed 100,000 t.
 Considering above, the Committee recomends that the
total catch not exceed 85,000 t.
ATLANTIC BIGEYE TUNA SUMMARY
Maximum Sustainable Yield 90,000 t-93,000 t 1
(68,000- 99,000) 2
Current (2006) Yield
65,000 t
Replacement Yield 2006
Slightly below MSY1
Relative Biomass (B2006/BMSY)
0.921 (0.85-1.07)2
Relative Fishing Mortality
FMSY
0.201 (0.07-0.33) 2
F2005/FMSY
0.871 (0.70-1.24) 2
Conservation & management measures in effect:
[Rec. 04-01] replaced [Rec. 79-01 and Rec. 99-01]
after June, 2005.
− Total allowable catch for 2005 is set at 81,400 t
for major country and entity
− Limits on numbers of fishing vessels less than the
average of 1991 and 1992.
− Specific limits of number of longline boats;
China(45), Chinese Taipei (98), Philippines (8).
− Specific limits of number of purse seine boats for Panama (3).
− No purse seine and baitboat fishing during November in the area
encompassed by 0º-5ºN and 10º W-20º W.
1
Base Case production model (Logistic) results based on catch data 1950-2005.
2 80% confidence limits
BET-Table 1. Estimated catches (t) of bigeye tuna (Thunnus obesus) by major
area, gear and flag.
TOTAL
Landings Bait boat
Longline
Other surf.
Purse seine
Discards Longline
Landings Angola
Argentina
Barbados
Belize
Belize (foreign obs.)
Benin
Brasil
Cambodia
Canada
Cape Verde
China P.R.
Chinese Taipei
Congo
Cuba
Côte D'Ivoire
Dominica
EC.España
EC.France
EC.Ireland
EC.Poland
EC.Portugal
EC.United Kingdom
FR.St Pierre et Miquelon
Faroe Islands
Gabon
Ghana
Grenada
Guatemala
Guinea Ecuatorial
Iceland
Japan
Korea, Republic of
Liberia
Libya
Maroc
Mexico
NEI (ETRO)
NEI (Flag related)
NEI (UK.OT)
Namibia
Netherlands Antilles
Norway
Panama
Philippines
Russian Federation
S. Tomé e Príncipe
Senegal
Seychelles
Seychelles (foreign obs.)
Sierra Leone
South Africa
St. Vincent and Grenadines
Sta. Lucia
Togo
Trinidad and Tobago
U.S.A.
U.S.S.R.
UK.Bermuda
UK.Sta Helena
Uruguay
Vanuatu
Venezuela
Discards Mexico
1981
67753
10124
41608
365
15656
0
0
0
0
0
0
40
505
0
0
72
0
1887
0
711
0
0
10010
8020
0
0
3086
0
0
0
0
780
0
0
0
0
22091
12274
0
0
622
0
0
0
0
0
0
0
2500
0
0
0
0
0
0
0
381
0
0
0
0
158
2832
0
14
86
0
1684
0
1982
73493
6922
51805
290
14476
0
0
0
0
0
0
45
776
0
0
200
0
2147
0
521
0
0
9332
7074
0
4
1861
0
0
0
0
791
0
0
0
0
33513
10809
0
0
625
0
338
0
0
0
0
0
2844
0
0
0
0
0
0
0
137
0
0
0
0
422
635
0
23
397
0
999
0
1983
59370
9796
33757
163
15654
0
0
0
0
0
0
0
521
0
0
293
0
1623
0
421
0
0
8794
8124
0
0
4075
0
0
0
0
491
0
0
0
0
15212
9383
0
0
552
0
1141
46
0
0
0
0
2732
0
0
0
0
0
0
0
187
0
0
14
191
315
352
0
14
605
0
4284
0
1984
71052
11439
43303
247
16063
0
0
0
0
0
0
0
656
0
0
167
0
925
0
447
0
0
13617
4254
0
0
4354
0
0
0
0
2162
0
0
0
0
24870
8989
0
0
120
0
157
369
0
0
0
0
3165
0
0
0
0
0
0
0
60
0
0
52
41
539
1233
0
19
714
0
4142
0
1985
78215
17651
52595
415
7554
0
0
100
0
0
0
0
419
0
0
112
0
1220
8
239
0
0
10340
4615
0
0
6457
0
0
0
0
1887
0
0
0
0
32103
10704
0
0
30
0
0
354
0
0
0
0
4461
0
0
0
0
0
0
0
102
0
0
18
22
639
870
0
0
597
0
2918
0
1986
65396
15618
39942
550
9286
0
0
41
0
0
0
15
873
0
11
86
0
1125
19
171
0
0
10884
4266
0
0
7428
0
0
0
0
1720
0
0
0
0
23081
6084
0
0
0
0
0
758
0
0
0
0
5173
0
0
0
0
0
0
0
168
0
0
24
0
1085
1071
0
0
177
0
1136
0
1987 1988 1989 1990 1991 1992
55976 65796 78068 84337 95264 98434
12631 9710 12672 18106 17750 16248
35570 47758 58389 56537 61556 62359
626
469
636
287
434
604
7148 7859 6371 9407 15524 19223
0
0
0
0
0
0
0
0
0
0
0
0
72
50
17
78
22
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
6
7
8
10
10
7
756
946
512
591
350
790
0
0
0
0
0
0
144
95
31
10
26
67
60
117
100
52
151
105
0
0
0
0
0
0
1488 1469
940 5755 13850 11546
10
10
14
15
12
12
190
151
87
62
34
56
0
0
0
0
0
0
0
0
0
0
0
0
8875 8475 8263 10355 14705 14656
3905 4161 3261 5023 5581 6888
0
0
0
0
0
0
0
0
0
0
0
0
5036 2818 5295 6233 5718 5796
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1178 1214 2158 5031 4090 2866
0
0
0
0
65
25
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
18961 32064 39540 35231 30356 34722
4438 4919 7896 2690
802
866
0
0
206
16
13
42
0
0
0
0
0
508
8
0
0
0
0
0
0
0
0
0
0
0
85
20
93
785 1221 2138
1406 2155 4650 5856 8982 6151
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
60
0
0
0
0
5616 3847 3157 5258 7446 9991
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
15
5
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
200
553
367
296
72
43
0
0
0
0
0
1
0
0
0
0
0
1
22
7
12
12
6
2
0
1
19
57
263
0
1074 1127
847
623
975
813
1887 1077
424
95
0
0
0
0
0
0
0
0
5
1
1
3
3
10
204
120
55
38
20
56
0
0
0
0
0
0
349
332
115
161
476
270
0
0
0
0
0
0
*An estimated Total Yield of 64701 t is obtained (0.2% larger), if 2005 figures of non-reporting Flags in 2006 are carried over to 2006.
1993
111568
16467
62871
648
31582
0
0
0
0
0
0
8
1256
0
124
85
70
13426
14
36
0
0
16782
12719
0
0
5616
0
0
0
1
3577
20
0
0
0
35053
377
65
1085
0
1
4594
4378
0
0
0
0
10138
0
0
0
9
0
0
0
88
3
0
86
3
1090
0
0
6
48
0
809
0
1994
132225
20290
78296
974
32665
0
0
0
0
0
0
9
601
0
111
209
428
19680
9
7
0
0
22096
12263
0
0
3099
0
0
0
87
4738
10
0
0
0
38503
386
53
500
0
4
5034
8964
36
7
0
0
13234
0
0
0
126
0
0
0
76
0
0
23
29
1402
0
0
6
37
0
457
0
1995
126284
25552
74816
561
25355
0
0
0
0
0
0
9
1935
0
148
66
476
18023
9
7
0
0
17849
8363
0
0
9662
0
0
0
10
5517
10
0
0
0
35477
423
57
400
0
0
5137
10697
0
29
0
0
9927
0
0
0
237
0
0
0
27
0
0
6
27
1209
0
0
10
80
0
457
0
1996
121131
18959
74900
353
26919
0
0
0
0
0
0
9
1707
0
144
16
520
21850
8
5
0
0
15393
9171
0
0
5810
0
0
0
0
5805
0
0
0
0
33171
1250
57
400
0
0
5839
11862
0
7
1893
0
4777
0
13
0
138
0
0
0
7
4
0
33
37
882
0
0
10
124
0
189
0
1997
108873
21037
68251
536
19049
0
0
0
24
0
0
30
1237
0
166
10
427
19242
0
0
0
0
12513
5980
0
0
5437
0
0
0
0
9829
1
0
4
0
26490
796
57
400
0
6
2746
16569
0
46
2890
0
2098
0
38
5
258
0
0
0
10
2
0
33
36
1138
0
0
12
69
0
274
0
1998
110008
21381
71836
428
16362
0
0
0
17
0
0
13
644
0
120
1
1503
16314
0
0
0
0
7115
5624
0
0
6334
0
0
0
0
13370
0
0
0
0
24330
163
57
400
0
8
1685
24896
0
16
2919
0
1252
1154
4
0
730
0
0
0
53
2
0
33
24
929
0
0
17
59
0
222
0
1999
127802
25868
76527
1373
24035
0
0
0
18
0
0
11
2024
32
263
1
7347
16837
0
0
0
0
13739
5529
0
0
3314
0
0
11
184
17764
0
0
0
1
21833
124
57
400
700
6
4011
24060
0
423
3428
0
580
2113
8
0
1473
0
0
0
55
1
0
0
19
1263
0
0
6
28
0
140
0
2000
102959
12634
71194
1221
17911
0
0
0
18
0
0
0
2768
0
327
2
6564
16795
0
0
2
0
11250
5949
0
0
1498
0
0
8
150
5910
0
0
0
0
24605
43
57
400
770
2
2285
15092
0
589
2359
0
952
975
91
0
1131
58
0
6
249
1216
0
0
5
574
0
0
8
25
0
226
0
2001
93767
15842
55265
1623
21037
0
0
0
6
0
0
0
2659
0
241
0
7210
16429
0
0
0
5
10134
4948
10
0
1605
0
0
0
121
12042
0
0
0
0
18087
1
57
31
857
2
3027
8470
0
640
2803
0
89
377
0
0
1308
0
0
2
239
506
1
0
11
1085
0
0
5
51
0
708
0
2002
76955
8367
46438
1475
20676
0
0
0
11
0
0
0
2582
0
279
1
5840
18483
0
16
0
0
10524
4293
0
0
2590
0
21
0
0
7106
0
0
0
0
15306
87
57
593
913
7
2248
531
0
274
1879
0
63
837
0
0
565
162
0
0
341
15
2
0
30
601
0
0
5
67
0
629
0
2003
91585
13437
54464
1313
22370
0
0
0
11
0
0
0
2455
0
182
1
7890
21563
0
16
0
0
10969
3940
0
0
1655
0
0
0
0
13557
0
0
0
0
19572
143
57
593
889
4
2504
0
0
215
2758
0
0
855
0
0
474
0
0
0
113
103
2
0
6
482
0
0
0
59
0
516
0
2004
86527
18879
48379
1234
18035
0
476
0
0
0
0
0
1496
0
143
1
6555
17717
0
0
0
0
8251
2926
0
0
3204
0
28
0
0
14901
0
0
0
0
18509
629
0
0
929
5
1387
0
0
177
3343
0
1521
1854
0
0
561
0
0
0
270
18
0
0
5
416
0
1
0
40
104
1060
0
2005
72738
15092
38872
534
18240
0
75
0
0
0
0
0
1081
0
187
1
6200
11984
0
0
0
0
7618
2816
33
0
4053
0
6
0
0
13917
0
1003
0
0
14772
770
0
0
519
4
1370
0
0
307
0
0
2310
1855
1
6
721
0
0
0
221
0
2
0
9
484
0
1
0
62
109
243
0
2006
64577
14671
32312
1447
16146
2006 %larger
64701
0.19
75
18
4
18
4
1479
1479
196
1
7200
2965
196
1
7200
2965
7464
2984
7464
2984
33
5068
3
5068
3
6
9141
9141
999
999
14772
2067
14772
2067
888
3
1516
888
3
1516
283
416
283
416
2415
1816
1
4
1267
2415
1816
1
4
1267
84
114
84
114
2
987
9
987
25
83
52
261
0
1
25
83
52
261
0