assessing the impact of bycatch on dolphin populations the case of the common dolphin in the eastern north atlantic评估海豚上的捕获种群的影响的情况下在北大西洋东部海豚.pdfVIP

Assessing the Impact of Bycatch on Dolphin Populations: The Case of the Common Dolphin in the Eastern North Atlantic 1 2 ´ 3 3 Laura Mannocci *, Willy Dabin , Emmanuelle Augeraud-Veron , Jean-Franc¸ois Dupuy , Christophe Barbraud2,4, Vincent Ridoux1,2 ´ ´ ´ ´ 1 Littoral, Environnement et Societes, UMR 7266, Universite de La Rochelle-CNRS, La Rochelle, France, 2 Observatoire Pelagis, UMS 3462, Universite de La Rochelle-CNRS, ´ ´ ´ La Rochelle, France, 3 Mathematiques Image et Applications, Universite de La Rochelle, La Rochelle, France, 4 Centre d’Etudes Biologiques de Chize, UPR 1934, CNRS, Villiers en Bois, France Abstract Fisheries interactions have been implicated in the decline of many marine vertebrates worldwide. In the eastern North Atlantic, at least 1000 common dolphins (Delphinus delphis) are bycaught each year, particularly in pelagic pair-trawls. We have assessed the resulting impact of bycatch on this population using a demographic modeling approach. We relied on a sample of females stranded along the French Atlantic and western Channel coasts. Strandings represent an extensive source of demographic information to monitor our study population. Necropsy analysis provided an estimate of individual age and reproductive state. Then we estimated effective survivorship (including natural and human-induced mortality), age at first reproduction and pregnancy rates. Reproductive parameters were consistent with literature, but effective survivorship was unexpectedly