This ReEort not to be cited without Erior reference to th~\cou~cilx) nternational Council\for the Exploration of the Sea _,t ) ',d~' C.M.l978fJt:~34....... -"- Pelagic Fish 8ommfttee~~ REPORT OF THE BLUEFN TUNA WORKNG GROUP Observations on the Size Composition of Bluefin Tuna Catches from 977 Edited by: H Aloncle, E Bakken, J Rodriguez-Roda and K Tiews This Report has not yet been approved by the nternational Council for the Exploration of the Sea; it has therefore at present the status of an internal document and does not represent advice given on behalf of the Council. The proviso that it shall not be cited without the consent of the Council should be strictly observed. x) General Secretary, CES, Charlottenlund Slot, DK-2920 Charlottenlund, Denmark.
REPORT OF THE BLUEFN TUNA WORKNG GROUP Contents Pa~ ntroduction l Material l Results 5 References 7 Tables 22 9 Figures - 2 32 -o-o-o-
- - ntroduction Reference is made to previous reports of the Bluefin Tuna Working Group (Statistical News Letters, NQ 20, 36 and 38, to Cooperative Research Reports, Ser. A., NQ 23, 40 and 7 as well as document c 0 N 0 97 7 J: 3. n 977 Mr. J. Hamre from the nstitute of Marine Research in Bergen, member of the Working Group since its beginning in 96, decided to withdraw because of too many other obligations and was replaced by Mr. E. Bakken of the same institute. Other Working Group members are at present Dr. P. les (Canada), Dr. H. Aloncle (France), Prof. K. Tiews (Federal Republic of Germany) (Chairman), Mrs. 0. Moura (Portugal), Dr. J. Rodriguez-Roda (Spain), Mr. R.C. Hennesmuth (USA) and Dr. James C. Tyler (USA). The members continued their work by correspondence and with other tuna research workers in the region. The data obtained for the fishing season 977 are presented in the following. Material Data on the size and age composition of Bluefin tuna catches were received from the following countries: Canada (Tables -4), Denmark (Table 5), France (Table 6), Norway (Table 7), Portugal (Table 8), Spain (Tables 9-3) and USA (Tables 4-8). Mrs. C.D. Burnett, Mr. P.C.F. Hurley and Dr. T.D. les reported that the-canadian landings of bluefin tuna in 977 for the west Atlan cic yielded 972 metric tons round weight (Table ), an increase of 26 mt or 3 % over the previous year: a) The purse seine fishery for juveniles off the eastern coast of the United States accounted for 298 mt, a decrease of 34 mt ( o%) from 976. b) The trap fishery in St. Margaret's Bay, Nova Scotia, took 368 mt of giant bluefin, an increase of 200 mt or 9 % over the previous year. c) The sport (rod and reel) fishery for giant bluefin declined from 342 mt in 976 to 302 mt in 977.
- 2 - Regulations introduced in the Canadian bluefin fishery in 974 have been maintained, subject to minor modifications in 975 and 976. Weights were obtained for 577 of the 78 large bluefin taken in five locations along the :~nadian Atlantic coast (Table 2). Mean weights rangeftom 298.6 to 437. kg. The size composition of monthly Prince Edward sland rod and reel landings is presented in Table 3. The average weight of fish increased as the season progressed, from 368.9 kg in August to 432.3 kg in October; the seasonal average was 394.4 kg, approximately the same as 976. The Canadian purse seine fishery for small bluefin took 298 mt. This fishery operated during July and August off the New York-New Jersey coast of the United States in 977. The size (fork length) composition of this catch is presented in Table 4. Fork lengths range from 44.5 to 63.6 cm, with an average length of 6.2 cm. n addition, 50 otoliths were extracted for age determination and several vertebrae and gonad samples were taken. n 977, ten giant bluefin were tagged and released: nine from the Bay of Chaleur area (Gulf of St. Lawrence) and one east of Halifax, Nova Scotia. Five tagged bluefi.n were recovered in 977; two fish were recaptured in the Gulf of Mexico from fish tagged in St. Margaret's Bay and in the Bay of Chaleur in 976; and bluefin tagged in the Bay of Chaleur area in 973, 975 and 976 were recaptured in the same general area. The commercial impoundment program in St. Margaret's Bay was increased to 8 impoundments in 977, and 77 giant tuna were successfully fattened for the Japanese market. n September, 290 fish were removed (average weight 393,2 kg) and in October, 427 fish were recovered (average weight 44.0 kg). One impoundment containing 3 giant bluefin was allocated for experimental purposes in St. Margaret's Bay. Canadian and U.S. scientists worked in a co-operative program involving studies of:
- 3 - internal body temperature, ambient water temperature and depth of free-swimming fish using ultrasonic telemetry; feeding behaviour; nutrition; tag retention; sex determination by hormone radioimmunoassay; aging validation; and tissuecontaminant analysis. Sampling of otoliths for age determination was continued with approximately 270 giant bluefin sampled in three different areas, in addition to the fifty juvenile bluefin sampled in the purse seine fishery. On the recommendation of the Standing Committee for Research and Statistics (CCAT), a bluefin tuna aging workshop was held in New York in March, 977. Scientists from several nations discussed existing aging techniques in an effort to standardize these procedures. The Proceedings of the workshop have been presented to the CCAT Secretariat for distribution and a second workshop is planned for 978. As a result of the 977 workshop, an experiment involving the administration of tetracycline to impounded giant bluefin in St. Margaret's Bay, up to 2 months prior to slaughter, was initiated to validate present aging procedures. Otoliths and vertebrae from these fish are presently being analyzed. The following papers were presented to CCAT's Standing Committee on Research and Statistics in November 977: ) Butler, -. J.A.: 2) Butler, J.J.A., The St. Margaret's Bay (Nova Scotia) Bluefin Research Program: A Progress Report (SCRS/77/89). and T.G. Pincock: The Ultrasonic Monitoring of mpounded Bluefin Tuna in St. Margaret's Bay. ( SCRS/77 /92). 3) Butler, M.J.A., and J.M. Mason, Jr.: Behaviour Studies on mpounded Bluefin Tuna (SCRS/77/93). 4) Hunt, J.J. (Editor): Proceedings of the Atlantic Bluefin Tuna Aging Workshop. Tir. Becket informed the Working Group that four of tagged bluefin recaptured in 977, and one of those recaptured in 976, were fish that had been released after capture by rod and reel. This supportsthe value of the technique even in the colder part of the bluefin range.
- 4 - Dr. Bagge submitted data on Danish and Swedish catches of 6 bluefin tuna made in the Kattegat (Table 5). French bluefin tuna catches from the Bay of Biscay were reported by Dr. Aloncle (Table 6). Mr. S.A. versen stated that except for one tuna caught 7 July (week 27) the Norwegian fishery started four weeks later in week 3. This is the usual time for starting the tuna seasonthere. 29 fishes, totalling 583 433 kilos were landed during the weeks 27-34. The main catch were landed in the two weeks 32 and 33. 65 catches were landed by 27 fishermen. The catches ranged between and 29 fishes. The bulk were caught on the coast of Hordaland and Sogn and Fjordane. Three fishes were reported from Rogaland, the neighbouring district south of Hordaland. The complete Norwegian catch is included in the Table 7.Only giant bluefin were caught.ndividual weights are lacking for 6 fishes in week 32. ndividual weights (gutted and without head) varied between 80 and 435 kilos, averaging 268.2 kilos, corresponding approximately to 230-560 kilos, mean 345 kilos live weight. No fishing stops or other restrictions were imposed. However, the fishery ended before September due to bad weather. No length measurements were recorded. Dr. Monteiro submitted the landing statistics of the Portuguese bluefin tuna catches made at Azores and Madeira slands (Table 8). Dr. Rodriguez-Roda informed the Working Group that in 977 three madragues were working in the south of Spain, 2 on the Atlantic coast at Barbate and Zahara de los Atunes and one on the Mediterranean coast at La Linea (Table 9). During the months of May, June and July the weather was not very satisfactory for the madrague fishery. Nevertheless it is evident that catches of bluefin tuna are steadily decreasing in this area ~total of 69 fish were measured)(table 0). Dr. Cort says that the period from July -August 977 was characterized by extremely bad weather which has cut down the activities of the Spanish tuna fleet in the Bay of Biscay. The improvement of weather during
- 5 - September made it possible that catches reached levels above the average. The catch per unit of effort was even the highest since 972: 972 973 974 975 976 977 74.9 75. 68.0 54.9 53. 8.2 kg The age composition of catches is given in Table. The information on the bluefin tuna catches made by bait boats in the Canary slands given for the first time was made by Mr. Santos-Guerra (Tables 2-3). The US length composition data were reported by Mr. M.D. Lange of the Miami Laboratory of the National Marine Fisheries Service (Tables 4-9). The fish were measured as straight fork length in centimeters and tabulated within one week :intervals across tl e respective fishing seasons. Tables 20-22 were submitted by Dr. J.C. Tyler (2). Results. ~rhe bluefin tuna catches of the Spanish madrague fishery which had recovered to 490 tons in 976 declined again to 339 tons in 977. 2. The catches of the Norwegian fishery increased instead from 69 fish in 976 to 2 9 giant tuna (= 587 tons), but were still smaller than in 974 and 975. 3. The French fishery in the Bay of Biscay recovered again to the le v el of 975 after a drastic drop of landings in 976 to on8 half due to the abnormally high water temperature until the second half of July 976. French catches increased from 268 tons in 976 to 487 tons in 977. The Spanish catches per unit of effort in this are2 were the highest since 972. 4. The Spanish bluefin tuna catches in the vraters of the Cenary slands amounted 250 tons and vere the largest since 97 4.
... 6-5. The overa.ll Canadian catches continued to increase and reached 972 tons, which was the largest catch since 97+. Also the US catcl.es amounting to 945 tons were slightly higher than in 976 and the second largest since 974. 6. The Norwegian Bluefin Tuna catches were of the knovm size composition (Fig. )., t tallied neither with the Canadian catch of giant tune., which were considerable larger as in 976, nor with the catches made in the Canary slands which consisted largely of smalle:t' fish. The Spanish madrague catch shows a recruit of some 2 year old fish, while the older component of the catch tallies with the length composition of the US catch of giant tuna (Fig. 2). As has to be expected the size composition of the US and Canadian purse seine catches tally widely. 7. The US and Canadian purse seine catches were dominated by 4 year olds. This year class dominated the catches already in 97 4, 975 and 976. The second largest group \'ras that of 2 year olds. 8. n the live bait fishery in the Bay of Biscay the strongest year class was again that of 2 year olds which was also the case in 975 and 976. This indicates strongly that the fluctuation pattern in the strenth of the recruit year classes did not tally in the eastern and western Atlantic during these years.
- 7 - References ( ) ALONCLE, H., HAMRE, J., RODRG\JEZ-RODA, J. and TEWS, K., 974: Fifth Repoit of the Bluefin Tuna Working Group. Observations on the size composition of Bluefin ~una catches from 970 to 972. Cons. int. l~plor. Mer, Coop. Research Report, No. 44, pp. -52 (2) ALONCLE, H., HAMRE, J., RODRGUE.0-RODA, J. and TEWS, K., 977: Sixth report of the Bluefin Tuna Working Group. Observations on the size composition of Bluefin Tu~a catches from 973 to 975. Cons. int.. E:cplor.. Mer, Coop. Research Report, No.. 7, pp.. - 49 (3) BARD, F.X., ORT,J.L., 976: Estimation des captures franco-espagnoles de thon rouge, Thunnus thynnus (L.) 972-976 CCAT: SCRS/76/ES3 (4) BURNETT, C.D., BUTLER, M.J.. A.., DCYSON, C.A., 976: Canadian Taggir-g and Recapture Data of Large Pelagic Eish for the Period 970-976. ( SCRS/76 /87) (5) BUTLER, M.J.A., CADDY, J.F.., DCKSO~~, C.A., HUNT, J.J., BURNETT, C.D., 976: Apparent Age anc. Growth, based on Otolith analysis, of Gic:.nt Blue fin Tuna ( Thunnus thynnus thynnus) in the 975-976 Canadian Catch. (SCRS/76;87) (6) BUTLER, M.J.A., 976: The Trap (l'~ackerel) and mpoundment (Bluefin) Fishery in St. Margaret's Bay, Nova Scotia: ts Development. (SCRS/76/88) (7) CORT, J.L., FERNANDEZ P'ATO, C., and JARDENAS, E. de, 976: Observations sur la maturation sexuelle du thon rouge, ThuE~ thynnus (L.) du Golfe de Gascogne. Cons. int. Explor. Mer, C.M. 976: J (8) HAMRE, J., LOZANO, F., RODRGUEZ-RODA, J. and TEWS, K., 966: Second Report from the Bluefin Tuna Working Group. On the development of the Bluefin Tuna fisheries from 950 to 964 and further observations on size composition of Bluefin Tuna catches. Cons. int. Explor. Mer, Stat. News Letters, No. 25, pp. -34 (g) HM~RE, J., LOZANO, F., RODRGUEZ-RODA, J. and TEWS, K., 968: Third Report from the Bluefin Tuna Working Group. Observations on the size composition of Bluefin Tuna catches from 965-966. Cons. int. Explor. Mer, Stat. News Letters, No. 38, pp. -27
- 8 - (0) HA}RE, J., MAURN, C., RODRGUEZ-RODA, J. and TEWS, K., 97: Report of the Bluefin Tuna Working Group. Observations on the size composition of Bluefin Tuna catches from 967-969. Cons. int. Explor. Mer, Coop. Res., Ser. A, No. 23, pp. -49 () HMli~E, J., and TEWS, K., 964: (2) TYLER, J.C., Report from the Bluefin Tuna Working Group. On the size composition of Tuna catches from 956-962. Cons. int. Explor. Mer, Stat. News Letters, No. 20, pp. -43 BAGLN, R.E., BERRY, F.H. and RVAS, L.R., 977: A review of the United States scientific research on the biology and the status of Bluefin Tuna stocks and of the Bluefin Tuna fisheries. CCAT Working Document SCRS/977, pp. -
- 9... Table. Canadian Catches of Blue fin Tuna from Atlantic Ocean, 962-77 Landings (Nominal Catch in Metric Tons, Round \'Veight) -- Purse Rod & Year Traps** seine reel* Total 962 37 40 77 963 229 323 90 642 964 38 579 99 996 965 75 46 90 726 966 2 02 33 967 298 58 356 968 253 80 433 969 407 70 577 970 275 6 5 587 97 68 935 28 3 972 36 202 26 499 973 60 639 25 04 974 300 03 365 768 975 4 295 93 629 976 72 332 342 846 977 372 298 302 972 *Note: Prior to 974 tagged and/or released fish are included in the rod and reel totals. * * >: o t e : From 9 6 2-7 4 the catch in c u des a sm a proportion of incidental longline catches.
Table 2. Size composition (round Vveight per mille by 0 kg unit) of large... ~luefin r.r una captured in five localities along the Canadian Atlantic Coast in 976 Size P.E.. Nfld. N. B. Que. N S. class (kg) Rod and reel Rod and reel Rod and reel Rod and reel Trap Rod and reel Total n n n n n n n smooth. so - - - - - 90 200 - - - - - 20 220 - - - - - 230 - - - 2-2 3 240 - - - 9-0 5 250 - - 6-8 6 260 - - - - - 7 270 - - - 4-5 0 280 3 - - - 8-2 3 290 4 - - 6-2 6 300 9 - - 22-32 9 30 0 2 24-38 25 320 2 3 32 48 36 0 /oo - - 0 330 5 5-40 - 60 37 340 2 5 39-66 4 350 27 9 44-8 48 360 25 3 2 57 98 58 370 25 4 58 99 66 380 34 25 2 64 26 78 390 39 22 2 54-7 8 400 33 22 4 64 24 75 40 4 9 3 52-5 7 420 33 57-02 62 430 30 2 37 8 56 440 25 o 52-88 49 450 4 33 50 33 460 5 4-3 - 50 29 470 5-29 - 35 24 480 7 23-3 9 490 6 2 3-2 3 500 2-5 2 9 7 50-5 7 5 520-4 5 4 530 2 2 540 f-j ( ctd)
Continuation table 2. Totals 440 5 83 Mean weight (kg) 394.4 298.6 396.7 Size class 80 kg = 80.0-89.9 22 98 397.7 388. 437. 000 --' --' 9 577
- 2 - Table 3 Size composition of large 8luefin caught by rod and reel off Prince Edward sland during four consecutive months of the 977 season (.number of fish and round weight rer mille by 0 kg unit). Size July August September October class No. of No. of No. of No. of (kg) fish %o fish %o fish %" fish %o 200 5 20 220 8 230 240 250 8 260 270 5 280 2 5 0 290 2 5 2 0 300 6 45 3 5 30 7 53 3 5 320 4 30 8 39 330 7 53 8 39 340 3 99 7 34 0 350 83 4 68 2 20 360 9 68 3 63 3 29 370 000 9 68 2 58 3 29 380 6 2 6 78 2 20 390 2 9 22 07 5 49 400 9 68 8 88 6 59 40 8 6 22 07 08 420 8 6 2 58 3 27 430 2 5 5 73 3 27 440 8 6 78 8 78 450 2 5 3 5 9 88 460 2 5 4 20 9 88 4 70 2 0 3 30 480 2 0 5 49 490 5 5 4-9 500 2 20 50 5 20 530 0 ------------------ -- ---- ---------- -- ------------ - --- - Totals 000 32 000 205 000.l 0 2 000 --------- ~- ea n \'lt? i <J h t j_~gj -- --- -~ ~ 0--~-- -- 3 6 8. 9 392.2 432.2 Size class 200 kg = 200.0-209.9 -- -- ----- -----------------------------------------------------
- 3 - Table 4. Size (fork length) composition of small Bluefin taken off the U.S. coast by Canadian purse-seine v~ssels in 977. Size Class (cm) No. of Fish smoothed 40 45 50 55 60 65 70 75 80 85 90 95 loo 05 0 5 20 25 30 35 40 45 50 55 60 5 4 8 68 76 2 2 0 7 9 29 34 76 98 99 53 67 35 5 3 7 5 93 04 29 3 4 23 26 40 46 04 34 35 72 92 48 7 4 'rotal: 732 000 Size category 40~40.0-44.9 (fork length caiper)
- 4 - W?ig~t dis~r~hution of B~uefin ~~~~ l3n~ed in Denm:rk i.l"l 4 977.. The weight gr~y~lp refe~.:::; to gutted fisl:l,~:i th r;ilj s (kg) \ eight group ---- -. kg ~---~-------2~~~------- 270-27~ 290-294 340-3hh 350 3C: ':.., 360-364 Total 6
- 5 - Table 6. French Bluefin Tuna catches in 977 from the Golfe de Gascogne (France) in kg Date 09.06. - 5. 06. 977 27 6.06. - 22.06.977 57 60 23.06. - 29.06.977 3 253 30.06. - 07.977 56 653 7.07. - 3.07.977 46 755 4.07. - 20.07.977 50 73 2. 07. - 27.07.977 60 93 28.07. - 03.08.977 0 04.08. - 0. 08. 977 4 3 08. - 7.08. 977 577 8.08. 24.08.977 302 25.08. - 3.08.977 2 86 0 09. - 07.09.977 32 896 08.09. - 4.09.977 7 325 5.09. - 2. 09. 977 27 864 22.09. - 28.09.977 57 353 29.09. - 05.0.977 20 20 06. 0. - 2.0.977 7 988 Total weight Fish below 30 kg Fish above 30 kg 486 794
- 6 - Table Size composition (kg) of Norwegian Bluefin Tuna catches by smoothed weight frequency (%a) in 977. Group means Week No. w' w 27 3 32 33 34 Total 82. 234 87 240 2 92 247 2 2 2 97 253 3 3 3 3 202 260 7 6 4 5 207 266 3 8 4 6 22 272 4 7 0 27 279 30 7 2 5 222 285 33 25 20 23 227 292 250 43 29 29 29 232 298 500,43 32 30 36 32 237 305 250 43 44 32 07 39 242 3 59 58 43 07 52 247 37 66 62 54 36 59 252 324 72 6 60 36 6 257 330 69 62 6 72 62 262 337 59 64 59 36 6 267 343 72 68 57 63 272 350 92 74 63 70 277 356 89 68 65 36 67 282 362 59 52 59 72 55 287 369 33 4 54 72 46 292 375 33 39 5 72 44 297 382 33 38 47 36 42 302 388 20 32 42 36 36 307 395 3 26 35 72 29 32 40 0 8 28 36 22 37 408 3 3 2 36 6 322 44 9 4 72 327 420 8 0 36 9 332 427 8 0 8 337 433 6 8 6 342 4 0 2 4 3 347 446 3 2 352 453 2 2 2 357 459 2 2 362 465 2 2 367 472 37 2 478 3""'~ 485 382 49 387 498 392 504 397 50 402 57 407 523 42 530 47 536 422 543 427 549 432 555 437 562 n 76 227 864 7 275 \V' 232 9732 326644 234886 939 583433 '-"'' 232. 0 259.6 266. 2 2 7. 9 277. 0 268. 2 N 243 29 \V' 330543 587332 ~ 265. q 268.
- 7 - Table 8. Portuguese Blue fin Tuna landings at Azores and Madeira slands in 977 in kg Month Azores sland Madeira slands Total January 600 600 February 600 600 March April May June 33 900 33 900 July 3 666 3 666 August 2 723 2 723 September 84 483 84 483 October Total 8 872 36 00 54 972 Table g. Bluefin Tuna catch from three madragues in Southern Spain (Barbate, Zahara de los Atures and La Linea) in 977: Bar bate Number of fish kg Big bluefin tuna 245 263 300 Little bluefin tuna g~ g~9 l_g ~--------~ ~-2~Q Zahara de los Atunes Bluefin tuna La Linea Bluefin tuna 0 0 Total 626 339 247
- 8 - Table 0. Size composition of Spanish madrague catches of Bluefin Tuna (Thunnus thynnus.) at Barbate in 977 3=== z======================~-=========~======= ======================B Length group cm. foo smoothed 55 59.9.5 60 64o9 4.4 65 69.9.8?0?4.9 20.7 75?9.9 22.2 80 84.9 25.2 85 89.9 29.6 90 94.9 28. 95 99.9 3. 200 204.9 53.3 205 209.9?9.9 20 24.9 88.8 25-29.9 94o7 220 224.9 05.0 225 229.9 93.2 230 234.9 5?.? 235 239.9 4.. 4 240-244.9 4?.3 245 249.9 50.3 250 254.9 4.4 255 259.9 28. 260-264.9 22.2 265 269.9 3.3 270 274.9 4.4 275 279.9 3.0 280-284.9.5 N 69 000.
- 9 - Table. Demographic structure of Spanish Bluefin catch and total number of fish caught in the Bay of Biscay Age group Number of fish 4 934 46 72 0 393 V 5 37 V 346 V 29 V 94 Total 68 069 Table 2. Spanish catches of Bluefin Tuna in the Canary slands, 974-977 Year Catch in metric tons and round weight 974 546 975 978 976 832 977 25 0
- 20 - Table 3. Size composition of Bluefin Tuna caught by baitboats in the Canary slands during the 977 season. 8j~ze c;j a:-3s C: e) 00 c /eo S"0othe:.i e 80 90 20(' 20?20 230 2hO 250 ~60?70 280 290 300 30 3?0 330 3Lt('l 350 360 370 380 390 '+00 8??L, 20 2 24 ;n 66 78 87 p.r; 92 R"'2: _... 60 h()../ - 60 6() l~8 28 6 0 8 2 Nn~be~ cf fish ~ 2 t: ono
\) f--l Table 4. Sample length frequency by week of giant Atlantic Bluefin Tuna caught by rod and reel in the Bahamas in 977(sampe = 5 fish).. Length 5/5-5/22-5/29-6/5- t+ Week 0 /oo cm 5/2 5/28 6/4 6/ smoothed 6 83 66 2 265-269 2 66 270-274 33 E274 8 6 5 000 25
.. i. ; : Table 5. Samhle len~th-frequency by week of small Atlantic Bluefin una caught by sport fis ing of the U.S. Mld-Atlantic coast in 977. Total catch 56 MT, total samples 96 fish..... 0 i.... 0 Week. '... 0 s \...0 \...0 \...0 \...0 c- c- c- c- c- CfJ CfJ CfJ CfJ 0\ 0\ 0\ 0\ 0.......... 0 0. rl ~ ~ CfJ Lr\ C\J 0\ \...0 t<"\ 0 \...0 t<"\ 0 c- t<"\ 0 c-.._j- 0. ~ ~ C\J ~ C\J t<"\ ~ C\l C\J ~ ~ C\J cd s +' w. OD +' $:::!... 0............. 0 Q) Lr\ \...0 \...0 \...0 \...0 c- c- c- c- c- CfJ CfJ CfJ CfJ 0\ 0\ 0\ 0 0 H................. ~ ()\ Lr\ C\J ()\ \...0 t<"\ 0 c-.._j- ~ c- """"" ~ ~ CfJ ~ ~ CfJ 8 0 C\J ~ ~ C\J ~ ~ C\J t<"\ ~ C\J C\J ~ ~ 8 0 4 20 2 3 8 22 0 4 24 0 3 26 2 2 9 28 2 3 5 0 30 0 5 32 4 34 5 36 4 4 5 3 44 0 2 46 4 48 4 50 0 52 l 0 54 r 5 56 58 3 4 i! 2 5 7 39 60 4 i 5 73 62 5; ~4 20 84 64 4: l2 8 54 68 66!4 ' 6 32 )2 2 26 70!3 4 9 72 ' 9 i 74 6 i 9 29 76 2 4 35 78 9 9 37 ; 80 5 i! 7 37 5 ( c td.) \) \)
Continued table 2_ Week - \.0 \.0 '"d \.0. \.0. :'-. :'- :'- :'- :'- CO (j)... CO CO CO 0\ 0\ 0\ El....... 0\ ~ -r- CO.....! L!\ -0 C\l -r- 0\ -r- \.0 t<\ 0 \.0 t<\ 0 :'- -P C\l -r- C\l t<\ t<\ 0 :'- -=:;:f- -r- C\l C\l 0 -r- -r- C\l 0 --- -- -~.! El -P QD L!\ \.0 \.0 UJ. \.0 ~.. \.0. :'-. :'- :'- :'- :'- CO CO rl...... CO. CO 0\. 0\. 0\. m 0... -P 0 Q) 0\ L!\ C\l 0\ \.0 t<\ 0 :'- -=:;:f- -r- :'- -=:;:f- -r- CO -=:;:f- -r- CO 0 ~ H C\l -r- -r- (\) -r- -r- C\l t<\ ~ C\l C\l -r- --- E-l 0 82 2 6 30 84 86 4 29 2 88 3 8 34 ~ go 2 2 6 32 92 4 l 5 25 3 94 3 4 96 2 0 6 98 2 6 00 2 l 3! 2 02 ; 5 4 [\) i 0 9...N! 04 r! f 06 j 2 3 4! 6 25 08 3 2 l 0 f 5 23! ' f j 2 l 2 3 i l : i j i 4! j 5 t ' t! 6 ' 0 3 l : 8 i ' i 8 ' t 2 20 ' 4 3 < 22 8! j ' f t 24 0 l 5 i ~ ~ 26 ' 3 3 rf [ : '! f 28! t 4 5 t ; j 30 l l 2 5 j ; ' l! 32 2 0 i.; t i! 34 t 2 9 i l i 36 8! l 38! ' 2 6! i! --- 0 i 3 j ~ j!50 i f! 52! 0 t!! l 54 3! t l f l 0 \ t (ctd) r ' l!! -
- 24 - m 8t[+oorns ooj 0 "L" Z - L L~. L. 9 ~ - L o~ "L 6 -"L" "L"6-9 9z 9 ~z -"9"6~...--. 9. 8 ~ -"9"6~ GJ rl p -P re) g G) r- -P 0 >=! U0 0. 9. ~ 9 t - ~ 6z tt+:su8'j 0..--t<\..--0..-t<\..-O 0 0...-- --»~--- r~ - --- o..-ooo..-oo m m m "9"~~-..- {'<\. r ---- ~ - -t-~~ ~ - ---l-.--..-..- ~ '<\ \..0... -... ---r-- '<\..,-.-..---- ~ -... --- --t-------- ~ m ------------+------... ----4----- -' -- '------------ \..0 ~ N ~.. ---- ----.. ------------,---- l\..0 '-.-------- ---t-- ----~ ~.. -- -------t----- ro -- - --------~ l'r' ---r------ -... -t-..- -r-......l.-. - \..OCJOC\J"<j-\..OCDO ~ m m \..0 \..0 \..0 \..0 \..0 c-- U2 or-.,.-.,.-.,.-.,.-.,.-.,.-...--
Table 6. Sample length-fre~uency by week of giant Atlantic Bluefin Tuna caught by hand-gear off the NE coast of the US in 977 (total catch 634 MT, total sample= 062 fish). Week E J' oo 6/26:.. 7/3-7/0-7/7-7/24-7/3-8/7-8/4-8/2-8/20-9/4- smoothed 7/2 7/9 7/6 7/23 7/30 8/6 8/3 8/20 8/27 9/3 9/0 2 2 4 3 2 5 8 2 7 5 '\) 2 4 3 4 2 22 24 Vl 2 2 2 2 2 7 3 39 48 2 2 2 6 2 4 4 5 02 86 2 2 69 54 93 68 64 47 2 4 2 ~ 6 6 23 0 3 8 25 4 24 5 4 3 2 5 6 20 7 34 7 24 20 0 5 6 2 3 7 25 7 33 23 20 3 6 2 2 30 2 20 22 23 7 9 6 95 03 8 67 28 35 3 3 4 2 2 2 4 2 0 6 0 6 9 4 0 9 7 8 6 8 4 6~ l~ 2 2 4 3 5 2 4 3 5 2 2 062 000 2 23 48 9 63 88 57 36 22 77 3 Length 6/9- cm 6/25 70-74 75-79 80-84 85-89 90-94 95-99 200-204 205-209 20-24 25-29 220-224 225-229 230-234 235-239 240-244 245-249 2 250-254 3 255-259 260-264 265-269 270-274 275-279 280-284' 285-289 290-294 295-299 :299 5 70
- 26 - Table 7. Gample length-frequency by week of small Atlantic Length cm 54 56 58 60 66 68 70 72 74 76 78 80 82 84 86 T. luefin ~.'una caught by U. S. purse-seine fleet in 977 (total catch = 972r T, total sampled 682 fish) ---r 2.6.-. 9.6.- 8.6. 25.6. 9 35 00 83 7 4 8 2 44 53 2 3 26.6._; 2.7. 4 2 39 25 9., Total ~ 2 0 0 2 68 83 0 /oo 92 2 2 94 3 3 96 2 3 98 2 7 0 8 00 7 22 29 5 02 5 25 3 8 04 3 9 33 7 06 4 3 7 2 08 3 7 0 6 0 2 2 4 2 6 5 6 4 7 9 6 2 6 5 24 39 3 8 5 62 3 7 20 84 28 ' 23 ' 22 00 05 205 25 24 04 0 2 26 09 26 52 4 7 00 68 28 28 3 4 30 30 5 6 2 4 32 8 4 2 7 34 3 4 3 36 0 38 0 40 0 0 42 2 44 46 48 2 3 50 52 3 4 2 54 5 6 3 56 2 58 4 5 3 60 5 6 4 62 2 7 0 5 64 5 2 7 5 66 6 8 4 68 3 4 4 70 2 4 6 3 72 : o ~6 38 7 0 0 smoothed 74 --~---l j ~--------~--- -----~--- -- j 2 s;------ : 7 7! 7 9 6 : 5! 6 8? n n n 0 0 0 4 6 5 87 80 35 8 0
- 27 - Table s. Sample length-frequency by week of small Atlantic Blue fin Tuna caught and or tagged by U.S. purse-seine fleet in 977 (total catch 86MT, total sampled= 2388 fish) Week 'Length 26.6.! 3.7.- 0.7.- 7.7.- {! Total 0 /oo cm -2.7. 9.7. 6.7. 23.7.! smoothed 50 0 52 0 54 6 3 9 6 56 39 2 2 43 7 58 62 2 8 72 23 60 30 7 38 6 62 4 2 6 5 64 0 66 0 68 2 70 72 6 8 5 74 22 24 32 76 3 45 3 5 84 04 78 76 494 7 4 60 20 80 49 478 4 29 670 246 82 20 306 27 8 47 80 84 75 85 6 84 86 8 9 2 20 27 88 4 5 3 t 90 0 l 92 0 i ~ l 02 2 2 4 2 04-2 2 06 6 2 8 2 0 5 6 3 08 2 3 3 2 2 3 2 4 0 6 2 2 8 20 4 3 7 3 22 5 3 2 0 4 24 5 3 5 3 5 26 3 3 2 8 4 28 2 2 4 2 30 0 Sx 20 707 373 98 2388 000 ----... ------- -----~-- ---------- -------- -------- ----------
Table 2 Sample length-frequency by week of giant Atlantic bluefin Tuna caught by U. S. purse-seine fleet in 977(total catch= 68MT~ total sampled = 388 fish). Week Length 8/28-9/4-9/- 9/8- o; cm 9/3 9/0 9/7 9/24 :4 00 smoothed 80-84 85-89 90-94 95-99 2 2 200-204 3 3 205-209 2 2 4 20-24 l 25-29 220-224 5 9 225-229 9 5 230-234 7 28 235-239 7 30 240-244 43 245-249 8 49 250-254 4 25 255-259 4 32 260-264 5 2 265-269 2 2 270-274 4 275-279 280-284 285-289 290-294 295-299 300-304 2 4 4 45 37 54 57 29 37 7 4 4 2 4 6 9 9 8 4 32 64 04 28 49 45 2 89 63 36 7 5 2 \) l:304 a o 83 254 338 000 CD
[\) '-.0 Table 20. US-Bluefin Tuna catches 974-977 Purse Seine, Hand Gear for Sport Fishing Totals Year Giant and School Tuna Giant Tuna for School Tuna (MT) 974 852 683 322 857 975 986 75 22 2 823 976 234 604 29 867 977 255* 634 56 945* ----- * ncludes estimated October catches of small (6MT) and medium (23MT) purse seine tuna in special scientific quotes
Table 2. Dates, catches and approximate age composition of 976 US Bluefin Tuna Fisheries Fishery Dates Catch by Catch by Approximate Small fish, open close number of fish round weight (MT) age composition by number purse seine ~ 2 % age 2 Re-gular Season 0 June 29 June 63 729 845 MT 88 % age 3 Tagging Season 8 July 8 July 2 007 f32 % age 224 MT 47 % age 2 2 % age 3 [47%age Small fish, 34 % age 2 sport Jan. 3 Dec. 2 970 29 MT 6 % age 3 Large fish, 3 % ages 4-5 purse seine Sept. 2 Sept. 59 65 MT age 7-9+...N Large fish, hand gear 8 May 6 Sept. 872 ----~Q._~~-- age 7-9+ 867 MT 0
\>J f-- Table 22. Dates, catches and approximate age composition of the 977 U.S. Bluefin Tuna Fisheries Fishery Small fish, purse seine open Regular season 5 June Tagging Season July Small fish, sport Large fish, purse seine Large fish, hand gear Northern Area Southern Area Medium fish, :r:urse seine lspecial quota) * Estimated? Oct. Jan. 3 Sept. Jan. Jan. 6 Sept.? Oct. Dates close 20 june 5 July? Oct. 24 Sept. ) 8 Sept. 5 Sept. 9 Sept. still open? Oct. Catch by number of fish 3 600 7 65 530* 4 932 556 946 250 * ) Last data included for catch in this table; season closes 3 Dec. Catch by round weight (MT) 972 MT 86 MT 6 MT* 56 MT 68 MT 634 MT 23 MT* 945 MT Approximate age composition by number ~ 25 % age 2 70 % age 4 5% ages,3,5 t 7 % age 9 % age 2 2 % ages 3-4 l-5 % age 69 % age 2 2 % age 3 4 % ages 4-5 age 7-9+ age 7-9 + age 5-8
50 USA Canada Norway Canary s la - 32-593 299 972 50 50 7,927 --l-288 ' ' 7 9 7, 50......... :........... "'.../. "'.....-"'"',... " ' ~....... 942 2J797 957........... '..... _... --- 50,;, ", " " ~-,.------- 50 0 00 50 200 250 300 350,00 450 500 Figure ~ Weight composition of Bluefin TUna catches made in USA, : Canada, Norway and Canary sland (Spain) kg