Estimate of exploitation rates and population size of skipjack tuna off the southeastern coast of Brazil

Jablonski, Silvio; Matsuura, Yasunobu

doi:10.1590/S0373-55241985000100003

Abstract

Size compositions and total landings of skipjack tuna caught in the southeastern Brazilian waters by bait-boats are used as the basis of the assessment of the population for 1980-1983 period, employing the length cohort analysis and virtual population analysis. From monthly size frequency data it is suggested that there is constant immigration and emigration of different modal groups in the fishing area with an interval of two to three months. The exploitation rate was very low for length class between 35-45 cm FL, then increased gradually. The weighted mean exploitation rates were 0.060 and 0.448, respectively for length classes smaller and larger than 55 cmFL. The estimate of the average number of fish attaining a size of 43 cm FL (recruit) was 11.0 x 10(6) fish for assumed values of M - 0.7 and K = 0.307. Increasing the fishing mortality rate by 30% and 50%, an estimated increment in yield is 8% and 12%, respectively. From virtual population analysis, we obtained the biomass estimate of skipjack population older than two years-old to be 70.3 thousand tonnes for assumed value of M = 0.7 and the estimated MSY was 24.6 thousand tonnes.

Biomass; Recruitment; Exploitation; Stock assessment; Potential yield; Commercial fishing; Continental shelf break; Pole-line fishing; Katsuwonus pelamis; Scombridae; SW Atlantic; Southern coast

ARTIGOS

Estimate of exploitation rates and population size of skipjack tuna off the southeastern coast of Brazil

Silvio Jablonski^I; Yasunobu Matsuura^II

^ISuperintendência do Desenvolvimento da Pesca (SUDEPE), Coordenadoria Regional do Rio de Janeiro

^IIInstituto Oceanográfico da Universidade de São Paulo

SYNOPSIS

Size compositions and total landings of skipjack tuna caught in the southeastern Brazilian waters by bait-boats are used as the basis of the assessment of the population for 1980-1983 period, employing the length cohort analysis and virtual population analysis. From monthly size frequency data it is suggested that there is constant immigration and emigration of different modal groups in the fishing area with an interval of two to three months. The exploitation rate was very low for length class between 35-45 cm FL, then increased gradually. The weighted mean exploitation rates were 0.060 and 0.448, respectively for length classes smaller and larger than 55 cmFL. The estimate of the average number of fish attaining a size of 43 cm FL (recruit) was 11.0 x 10⁶ fish for assumed values of M - 0.7 and K = 0.307. Increasing the fishing mortality rate by 30% and 50%, an estimated increment in yield is 8% and 12%, respectively. From virtual population analysis, we obtained the biomass estimate of skipjack population older than two years-old to be 70.3 thousand tonnes for assumed value of M = 0.7 and the estimated MSY was 24.6 thousand tonnes.

Descriptors: Biomass, Recruitment, Exploitation, Stock assessment, Potential yield, Commercial fishing, Continental shelf break, Pole-line fishing, Katsuwonus pelamis, Scombridae, SW Atlantic, Southern coast: Brazil,

Descritores: Biomassa, Recrutamento, Explotaçio, Estimativa do estoque, Rendimento potencial, Pesca comercial, Borda da plataforma continental, Pesca com linha/isca-viva, Katsuwonus pelamis, Scombridae, Atlântico Sul Ocidental, Costa sul: Brasil, Costa sudeste: Brasil.

Full text available only in PDF format.

Texto completo disponível apenas em PDF.

Acknowledgements

We thank Dr Roger Bailey of the Marine Laboratory, Aberdeen, for revision and critical reading of the manuscript. Dr Rodney Jones of the same laboratory kindly gave some useful suggestions on the paper.

Financial support came from the Financiadora de Estudos e Projetos S.A. (FINEP), for data processing with computer.

The junior author (Y.M.) received the research fellowship of the Conselho Nacional de Desenvolvimento Cientifico e Tecnológico (CNPq).

(Received 22-May-84; accepted 14-Dec-84)

AIKAWA, H. 1937. Notes on the shoal of bonito (skipjack, Katsuwonus pelamis) along the Pacific coast of Japan. Bull. Jap. Soc. scient. Fish., 6(1): 13-21.
______ & KATO, M. 1938. Age determination of fish (preliminary report). Bull. Jap. Soc. scient. Fish., 7(1):79-88.
ANKENBRANDT, L. 1983. Food habits of bait-caught skipjack tuna from the southwestern Atlantic ocean. Paper presented at the Proc. int. Skipjack Yr Progm. Conf., ICCAT, June 21-25, 1983, Tenerife, Spain.
BARD, F. X. & ANTOINE, L. 1983. Croissance du listao dans l'Atlantique Est. southwestern Atlantic ocean. Paper presented at the Proc. int. Skipjack Progm. Conf.,ICCAT, June 21-25, 1983, Tenerife, Spain.
BARDACH, J. E. 1983. Pacific tuna: biology, economics, and politics of a large fishery resources. In: Proceedings of the Joint Oceanographic Assembly 1982-general symposia. Canadian National Comm./SCOR, Ottawa, p. 76-94.
BATTS, B. S. 1972. Age and growth of the skipjack tuna, Katsuwonus pelamis (Linnaeus), in North Carolina waters. Chesapeake Sci., 13(4): 237-244.
BEVERTON, R. J. H. 1963. Maturation, growth and mortality of clupeid and engraulid stocks in relation to fishing. Rapp. P.-v. Réun. Cons, perm. int. Explor. Mer, 154:44-67.
BROCK, V. E. 1954. Some aspects of the biology of the aku, Katsuwonus pelamis, in the Hawaiian Islands. Pacif. Sci., 8 (1): 94-104.
CAYRE, P. 1979. Détermination de l'age de listao Katsuwonus pelamis L., debarqués à Dakar. Col. Vol. scient. Pap., ICCAT, 8(1): 196-200.
______ & FARRUGIO, H. 1983. Biologie de la reproduction du listão de l'océan Atlantique. Paper presented at the Proc. int. Skipjack Yr Progm. Conf., ICCAT, June 21-25, 1983, Tenerife, Spain.
CAYRE, P. & LALOE, F. 1983. Relations poids-longueur du listão de l'océan Atlantique. Paper presented at the Proc. int. Skipjack Yr Progm. Conf., ICCAT, June 21-25, 1983, Tenerife, Spain.
CHUR, V. N.; OVCHINNIKOV, V. V. & KOROLEVICH, L. I. 1983. Some problems of studying of age and growth of skipjack (Katsuwonus pelamis L.) of the Atlantic ocean. Paper presented at the Proc. int. Skipjack Yr Progm. Conf., ICCAT, June 21-25, 1983, Tenerife, Spain.
FONTENEAU, A. 1983. Etat des stocks de l'Atlantique par analyse des cohortes, analyse de production par recrue et par le medèle global. Paper presented at the Proc. int. Skipjack Yr Progm. Conf., ICCAT, June 21-25, 1983, Tenerife, Spain.
FUJINO, K.; SASAKI, K. & OKUMURA, S. 1981. Genetic diversity of skipjack tuna in the Atlantic, Indian, and Pacific Oceans. Bull. Jap. Soc. scient. Fish., 41 (2): 215-222.
GOLDBERG, S. R. & AU, D. W. K. 1983. The spawning schedule of skipjack tuna from southeastern Brazil as determined from histological examination of ovaries, with notes on spawning in the Caribbean. Paper presented at the Proc. int. Skipjack Yr Progm. Conf.,ICCAT, June 21-25, 1983, Tenerife, Spain.
GULLAND, J. A. 1965. Estimation of mortality rates. Annex to Artic Fisheries Working Group Reports. ICES CM 1965/Gadoid Fish. Comm. 3. p. 1-9. (mimeo).
______ 1971. The fish resources of the oceans. London, Fishing News (Books), 255 p.
JABLONSKI, S.; BRAILE, A. A.; ROMAO, C. M. & TEIXEIRA, M. S. M. 1983. Sexual maturity and sex-ratios of the skipjack tuna Katsuwonus pelamis (Linnaeus), from southeastern Brazil. Coll. Vol. scient. Papers, ICCAT, 20(1):217-233.
JONES, R. 1974. Assessing the long term effects of changes in fishing effort and mesh size from length composition data. ICES, CM 1974/F, 33:1922-1930.
______ 1979. An analysis of a Nephrops stock using length composition data. Rapp. P.-v. Reun. Cons. perm. int. Explor. Mer, 175:259-269.
______ 1981. The use of length composition data in fish stock assessments (with notes on VPA and cohort analysis). FAO Fish. Circ., 734:1-60.
JOSSE, E.; LE GUEN, J. C. & KEARNEY, R. F. 1979. Croissance des bonites à ventre raye. Commission du Pacifique sud Noumea, Nouvelle-Calédonie, Doc. occas., 11:1-33.
KAWASAKI, T. 1965. Ecology and dynamics of the skipjack population (I), (II). Nihon suisan shigen hogo kyokai, suisan kenkyu sosho (Study ser. Jap. Fish, Resour. Conserv. Ass.) (in Japanese).
KITCHELL, J. F.; NEILL, W. H.; DIZON, A. E. & MAGNUSON, J. J. 1978. Bioenergetic spectra of skipjack and yellowfin tunas. In: Sharp, G. D. & Dizon, A. ed. The physiological ecology of tunas. New York, Academic Press, p. 357-368.
MATSUURA, Y. 1982. Distribution and abundance of skipjack (Katsuwonus pelamis) larvae in eastern Brazilian waters. Bolm Inst, oceanogr., S Paulo, 31(2):5-7.
______ 1983a Development of a new Brazilian skipjack fishery in the Rio de Janeiro region. Bull. Jap. Soc. Fish. Oceanogr., 44:151-154.
______ 1983b Distribution and abundance of skipjack larvae in the western central Atlantic. Paper presented at the Proc. int. Skipjack Yr Progm. Conf.,ICCAT, June 21-25, 1983, Tenerife, Spain.
SCHAEFER, M. B. 1960. Report on the investigations of the Inter-American Tropical Tuna Commission for the year 1959. Rep. inter-Am. trop. Tuna Commn, 1959:39-156.
WILD, A. & FOREMAN, T. J. 1980. The ralationship between otolith increments and time for yellowfin and skipjack tuna marked with Tetracycline. Bull., inter-Am. trop. tuna Commn, 17(7):509-521.
YOKOTA, T.; TORIYAMA, M,; KANAI, F. & NOMURA, S. 1961. Studies on the feeding habit of fishes. Rep. Nankai reg. Fish. Res. Lab., 14:234 p.
ZAVALA-CAMIN, L. A. 1982. Informe sobre la presencia de bonito-listado (Katsuwonus pelamis) en el contenido estomacal de predadores capturados con palangre en el sudeste y sur del Brasil. Coll. Vol. Sci. Pap., ICCAT, 17(1): 209-210.
______ 1983. Areas de crescimiento de listado obtenidas por medio de datos historicos de examenes de contenido estomacal de predadores. Paper presented at the Proc. int. Skipjack Yr Progm. Conf., ICCAT, June 21-25, 1983, Tenerife, Spain.

Publication Dates

Publication in this collection
01 June 2012
Date of issue
1985

History

Accepted
14 Dec 1984
Received
22 May 1984

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

[1] AIKAWA, H. 1937. Notes on the shoal of bonito (skipjack, Katsuwonus pelamis) along the Pacific coast of Japan. Bull. Jap. Soc. scient. Fish., 6(1): 13-21.

[2] ______ & KATO, M. 1938. Age determination of fish (preliminary report). Bull. Jap. Soc. scient. Fish., 7(1):79-88.

[3] ANKENBRANDT, L. 1983. Food habits of bait-caught skipjack tuna from the southwestern Atlantic ocean. Paper presented at the Proc. int. Skipjack Yr Progm. Conf., ICCAT, June 21-25, 1983, Tenerife, Spain.

[4] BARD, F. X. & ANTOINE, L. 1983. Croissance du listao dans l'Atlantique Est. southwestern Atlantic ocean. Paper presented at the Proc. int. Skipjack Progm. Conf.,ICCAT, June 21-25, 1983, Tenerife, Spain.

[5] BARDACH, J. E. 1983. Pacific tuna: biology, economics, and politics of a large fishery resources. In: Proceedings of the Joint Oceanographic Assembly 1982-general symposia. Canadian National Comm./SCOR, Ottawa, p. 76-94.

[6] BATTS, B. S. 1972. Age and growth of the skipjack tuna, Katsuwonus pelamis (Linnaeus), in North Carolina waters. Chesapeake Sci., 13(4): 237-244.

[7] BEVERTON, R. J. H. 1963. Maturation, growth and mortality of clupeid and engraulid stocks in relation to fishing. Rapp. P.-v. Réun. Cons, perm. int. Explor. Mer, 154:44-67.

[8] BROCK, V. E. 1954. Some aspects of the biology of the aku, Katsuwonus pelamis, in the Hawaiian Islands. Pacif. Sci., 8 (1): 94-104.

[9] CAYRE, P. 1979. Détermination de l'age de listao Katsuwonus pelamis L., debarqués à Dakar. Col. Vol. scient. Pap., ICCAT, 8(1): 196-200.

[10] ______ & FARRUGIO, H. 1983. Biologie de la reproduction du listão de l'océan Atlantique. Paper presented at the Proc. int. Skipjack Yr Progm. Conf., ICCAT, June 21-25, 1983, Tenerife, Spain.

[11] CAYRE, P. & LALOE, F. 1983. Relations poids-longueur du listão de l'océan Atlantique. Paper presented at the Proc. int. Skipjack Yr Progm. Conf., ICCAT, June 21-25, 1983, Tenerife, Spain.

[12] CHUR, V. N.; OVCHINNIKOV, V. V. & KOROLEVICH, L. I. 1983. Some problems of studying of age and growth of skipjack (Katsuwonus pelamis L.) of the Atlantic ocean. Paper presented at the Proc. int. Skipjack Yr Progm. Conf., ICCAT, June 21-25, 1983, Tenerife, Spain.

[13] FONTENEAU, A. 1983. Etat des stocks de l'Atlantique par analyse des cohortes, analyse de production par recrue et par le medèle global. Paper presented at the Proc. int. Skipjack Yr Progm. Conf., ICCAT, June 21-25, 1983, Tenerife, Spain.

[14] FUJINO, K.; SASAKI, K. & OKUMURA, S. 1981. Genetic diversity of skipjack tuna in the Atlantic, Indian, and Pacific Oceans. Bull. Jap. Soc. scient. Fish., 41 (2): 215-222.

[15] GOLDBERG, S. R. & AU, D. W. K. 1983. The spawning schedule of skipjack tuna from southeastern Brazil as determined from histological examination of ovaries, with notes on spawning in the Caribbean. Paper presented at the Proc. int. Skipjack Yr Progm. Conf.,ICCAT, June 21-25, 1983, Tenerife, Spain.

[16] GULLAND, J. A. 1965. Estimation of mortality rates. Annex to Artic Fisheries Working Group Reports. ICES CM 1965/Gadoid Fish. Comm. 3. p. 1-9. (mimeo).

[17] ______ 1971. The fish resources of the oceans. London, Fishing News (Books), 255 p.

[18] JABLONSKI, S.; BRAILE, A. A.; ROMAO, C. M. & TEIXEIRA, M. S. M. 1983. Sexual maturity and sex-ratios of the skipjack tuna Katsuwonus pelamis (Linnaeus), from southeastern Brazil. Coll. Vol. scient. Papers, ICCAT, 20(1):217-233.

[19] JONES, R. 1974. Assessing the long term effects of changes in fishing effort and mesh size from length composition data. ICES, CM 1974/F, 33:1922-1930.

[20] ______ 1979. An analysis of a Nephrops stock using length composition data. Rapp. P.-v. Reun. Cons. perm. int. Explor. Mer, 175:259-269.

[21] ______ 1981. The use of length composition data in fish stock assessments (with notes on VPA and cohort analysis). FAO Fish. Circ., 734:1-60.

[22] JOSSE, E.; LE GUEN, J. C. & KEARNEY, R. F. 1979. Croissance des bonites à ventre raye. Commission du Pacifique sud Noumea, Nouvelle-Calédonie, Doc. occas., 11:1-33.

[23] KAWASAKI, T. 1965. Ecology and dynamics of the skipjack population (I), (II). Nihon suisan shigen hogo kyokai, suisan kenkyu sosho (Study ser. Jap. Fish, Resour. Conserv. Ass.) (in Japanese).

[24] KITCHELL, J. F.; NEILL, W. H.; DIZON, A. E. & MAGNUSON, J. J. 1978. Bioenergetic spectra of skipjack and yellowfin tunas. In: Sharp, G. D. & Dizon, A. ed. The physiological ecology of tunas. New York, Academic Press, p. 357-368.

[25] MATSUURA, Y. 1982. Distribution and abundance of skipjack (Katsuwonus pelamis) larvae in eastern Brazilian waters. Bolm Inst, oceanogr., S Paulo, 31(2):5-7.

[26] ______ 1983a Development of a new Brazilian skipjack fishery in the Rio de Janeiro region. Bull. Jap. Soc. Fish. Oceanogr., 44:151-154.

[27] ______ 1983b Distribution and abundance of skipjack larvae in the western central Atlantic. Paper presented at the Proc. int. Skipjack Yr Progm. Conf.,ICCAT, June 21-25, 1983, Tenerife, Spain.

[28] SCHAEFER, M. B. 1960. Report on the investigations of the Inter-American Tropical Tuna Commission for the year 1959. Rep. inter-Am. trop. Tuna Commn, 1959:39-156.

[29] WILD, A. & FOREMAN, T. J. 1980. The ralationship between otolith increments and time for yellowfin and skipjack tuna marked with Tetracycline. Bull., inter-Am. trop. tuna Commn, 17(7):509-521.

[30] YOKOTA, T.; TORIYAMA, M,; KANAI, F. & NOMURA, S. 1961. Studies on the feeding habit of fishes. Rep. Nankai reg. Fish. Res. Lab., 14:234 p.

[31] ZAVALA-CAMIN, L. A. 1982. Informe sobre la presencia de bonito-listado (Katsuwonus pelamis) en el contenido estomacal de predadores capturados con palangre en el sudeste y sur del Brasil. Coll. Vol. Sci. Pap., ICCAT, 17(1): 209-210.

[32] ______ 1983. Areas de crescimiento de listado obtenidas por medio de datos historicos de examenes de contenido estomacal de predadores. Paper presented at the Proc. int. Skipjack Yr Progm. Conf., ICCAT, June 21-25, 1983, Tenerife, Spain.