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Validating an ecological model with fisheries management applications: the relationship between loggerhead by-catch and distance to the coast

Published online by Cambridge University Press:  06 July 2010

José C. Báez*
Affiliation:
Instituto Español de Oceanografía (IEO), Centro Oceanográfico de Málaga, Spain Universidad de Málaga, Departamento de Biología Animal, Málaga, Spain
Raimundo Real
Affiliation:
Universidad de Málaga, Departamento de Biología Animal, Málaga, Spain
Jesús Bellido
Affiliation:
Universidad de Málaga, Departamento de Biología Animal, Málaga, Spain Aula del Mar de Málaga, Avenida. Manuel Agustín Heredia 35, 29001 Málaga, Spain
David Macias
Affiliation:
Instituto Español de Oceanografía (IEO), Centro Oceanográfico de Málaga, Spain
José M. de la Serna
Affiliation:
Instituto Español de Oceanografía (IEO), Centro Oceanográfico de Málaga, Spain
Juan A. Camiñas
Affiliation:
Instituto Español de Oceanografía (IEO), Centro Oceanográfico de Málaga, Spain COPEMED, Oficina de Málaga, Paseo del Parque, Málaga, Spain
*
Correspondence should be addressed to: J.C. Báez, Instituto Español de Oceanografía (IEO), Centro Oceanográfico de Málaga, Spain emails: [email protected]; [email protected]

Abstract

On the one hand, a recent study on sea turtle by-catch during surface longline fishing targeting swordfish in the western Mediterranean Sea showed that sea turtle by-catch is independent of fishing effort and other technological factors. When the distance to the coast increases, there is a higher probability of catching a loggerhead turtle. The authors proposed to avoid fisheries further than 35 nautical miles (approximately 65 km) from the coast. However, the proposed 35 nautical miles limit could be useful where the continental shelf is narrow, as in the Balearic Sea, and useless where it widens. On the other hand, ecological model validation is considered essential for management application. The objective of the present paper is to validate the new fisheries loggerhead by-catch model in different areas outside the Balearic Sea with wider continental shelves, aimed at maintaining sustainable fishing activity compatible with the conservation of the loggerhead populations. Our present results validate the previous model, and stress the importance of the eco-geographical variable distance to the coast in understanding the loggerhead by-catch (or incidental capture) per unit effort for the longline fisheries targeting swordfish.

Type
Research Article
Copyright
Copyright © Marine Biological Association of the United Kingdom 2010

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References

REFERENCES

Bas, C. (2000) El mar Mediterráneo: recursos vivos y explotación. Barcelona: Ariel Ciencia, 518 pp.Google Scholar
Báez, J.C., Real, R., García-Soto, C., de la Serna, J.M., Macias, D. and Camiñas, J.A. (2007a) Sea turtle bycatch dependency on distance to the coast independent of fishing effort: implications for conservation and fisheries management. Marine Ecology Progress Series 338, 249256.CrossRefGoogle Scholar
Báez, J.C., Camiñas, J.A., Sagarminaga, R., Torreblanca, D. and Real, R. (2007b) Loggerhead incidental caught from Andalusia and Murcia waters during 2004. Munibe 25, 196201.Google Scholar
Báez, J.C., Real, R. and Camiñas, J.A. (2007c) Differential distribution within longline transects of loggerhead and swordfish captured by the Spanish Mediterranean surface longline fishery. Journal of the Marine Biological Association of the United Kingdom 87, 801803.CrossRefGoogle Scholar
Báez, J.C., Real, R., Macias, D., De La Serna, J.M., Bellido, J.J. and Camiñas, J.A. (2010) Swordfish Xiphias gladius Linnaeus 1758 and loggerhead Caretta caretta (Linnaeus, 1758) captures associated with different combinations of bait in the Western Mediterranean surface longline fishery. Journal of Applied Ichthyology 26, 126127.CrossRefGoogle Scholar
Camiñas, J.A., Báez, J.C., Valeiras, J. and Real, R. (2006) Differential loggerhead bycatch and direct mortality in surface longline according to boat strata and gear type. Scientia Marina 70, 661665.CrossRefGoogle Scholar
Cardona, L., Revelles, M., Carreras, C., San Felix, M., Gazo, M. and Aguilar, A. (2005) Western Mediterranean immature loggerhead turtles: habitat use in spring and summer assessed through satellite tracking and aerial surveys. Marine Biology 147, 583591.CrossRefGoogle Scholar
Cardona, L., Revelles, M., Parga, M.L., Tomás, J., Aguilar, A., Alegre, F., Raga, A. and Ferrer, X. (2009) Habitat use by loggerhead sea turtles Caretta caretta off the coast of eastern Spain results in a high vulnerability to neritic fishing gear. Marine Biology DOI: 10.1007/s00227-009-1288-9.CrossRefGoogle Scholar
Eckert, S.A., Moore, J.E., Dunn, D.C., van Buiten, R.S., Eckert, K.L. and Halpin, P.N. (2008) Modeling loggerhead turtle movement in the Mediterranean: importance of body size and oceanography. Ecological Applications 18, 290308.CrossRefGoogle ScholarPubMed
Gilman, E., Zollet, E., Beverly, S., Nakano, S., Davis, K., Shiode, D., Dalzell, P. and Kinan, I. (2006) Reducing sea turtle bycatch in pelagic longline fisheries. Fisheries 7, 223.Google Scholar
Gilman, E., Kobayashi, D., Swenarton, T., Brothers, N., Dalzell, P. and Kinan-Kelly, I.S. (2007) Reducing sea turtle interactions in the Hawaii-based longline swordfish fishery. Biological Conservation 139, 1928.CrossRefGoogle Scholar
Kerstetter, D.W. and Graves, J.E. (2006) Effects of circle versus J-style hooks on target and non-target species in a pelagic longline fishery. Fisheries Research 80, 239250.CrossRefGoogle Scholar
Lewison, R.L., Crowder, L.B., Read, A.J. and Freeman, S.A. (2004a) Understanding impacts of fisheries bycatch on marine megafauna. Trends in Ecology and Evolution 19, 598604.CrossRefGoogle Scholar
Lewison, R.L., Freeman, S.A. and Crowder, L.B. (2004b) Quantifying the effects of fisheries on threatened species: the impact of pelagic longlines on loggerhead and leatherback sea turtles. Ecology Letters 7, 221231.CrossRefGoogle Scholar
Piovano, S., Swimmer, Y. and Giacoma, C. (2009) Are circle hooks effective in reducing incidental captures of loggerhead sea turtles in a Mediterranean longline fishery? Aquatic Conservation: Marine and Freshwater Ecosystems DOI: 10.1002/aqc.1021.CrossRefGoogle Scholar
Read, A.J. (2007) Do circle hooks reduce the mortality of sea turtles in pelagic longlines? A review of recent experiments. Biological Conservation 135, 155169.CrossRefGoogle Scholar
Revelles, M., Cardona, L., Aguilar, A., San Felix, M. and Fernández, G. (2007) Habitat use by immature loggerhead sea turtles in the Algerian Basin (western Mediterranean): swimming behaviour, seasonality and dispersal pattern. Marine Biology 151, 15011515.CrossRefGoogle Scholar
Rykiel, E.J. (1996) Testing ecological models: the meaning of validation. Ecological Modelling 90, 229244.CrossRefGoogle Scholar
Serna de la, J.M., Ortiz de Urbina, J.M. and García-Barcelona, S. (2006) Resultados de la acción piloto (RAI-AP-52/2004) de pesca experimental con palangre de superficie dirigido al pez espada en el Mediterráneo occidental. Document SCRS-2006/163 ICCAT.Google Scholar
Sobrino, I., Baro, J. and Cumbreras, F. (1994) Las artes de pesca en el litoral gaditano. Cádiz: Diputación Provincial de Cádiz, 307 pp.Google Scholar
Shugart, H.H. (1984) A theory of forest dynamics: the ecological implications of forest succession models. New York: Springer-Verlag, 278 pp.CrossRefGoogle Scholar
Watson, J.W., Epperly, S.P., Shah, A.K. and Foster, D.G. (2005) Fishing methods to reduce sea turtle mortality associated with pelagic longlines. Canadian Journal of Fisheries and Aquatic Sciences 62, 965981.CrossRefGoogle Scholar