Do commercial fisheries display optimal foraging? The case of longline fishers in competition with odontocetes

International audience Depredation in longline fisheries by odontocete whales is a worldwide growing issue, having substantial socio-economic consequences for fishers as well as conservation implications for both fish resources and the depredating odontocete populations. An example of this is the de...

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Bibliographic Details
Published in:Canadian Journal of Fisheries and Aquatic Sciences
Main Authors: Richard, Gaëtan, Guinet, Christophe, Bonnel, Julien, Gasco, Nicolas, Tixier, Paul
Other Authors: Lab-STICC_ENSTAB_CID_TOMS, Laboratoire des sciences et techniques de l'information, de la communication et de la connaissance (Lab-STICC), École Nationale d'Ingénieurs de Brest (ENIB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Institut Mines-Télécom Paris (IMT)-Centre National de la Recherche Scientifique (CNRS)-Université Bretagne Loire (UBL)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom Paris (IMT)-École Nationale d'Ingénieurs de Brest (ENIB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Institut Mines-Télécom Paris (IMT)-Centre National de la Recherche Scientifique (CNRS)-Université Bretagne Loire (UBL)-IMT Atlantique (IMT Atlantique), Institut Mines-Télécom Paris (IMT), Biologie des Organismes et Ecosystèmes Aquatiques (BOREA), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC), Institut National de la Recherche Agronomique (INRA)-La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS), Pôle STIC_AP, École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne), Centre for Integrative Ecology, Deakin University Burwood, ANR-17-CE32-0007,OrcaDepred,OrcaDepred - Evaluation des conséquences écologiques et socio-économiques de la déprédation exercée par les cétacés sur les pêcheries à la palangre : Mise en œuvre d'une approche technico-économique en vue de sa suppression(2017)
Format: Article in Journal/Newspaper
Language:English
Published: HAL CCSD 2018
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Online Access:https://hal.science/hal-01572425
https://doi.org/10.1139/cjfas-2016-0498
Description
Summary:International audience Depredation in longline fisheries by odontocete whales is a worldwide growing issue, having substantial socio-economic consequences for fishers as well as conservation implications for both fish resources and the depredating odontocete populations. An example of this is the demersal longline fishery operating around the Crozet Archipelago and Kerguelen Island, southern Indian Ocean, where killer whales (Orcinus orca) and sperm whales (Physeter macrocephalus) depredate hooked Patagonian toothfish (Dissostichus eleginoides). It is of great interest to better understand relationships of this modern fishery with its environment. Thus, we examined the factors influencing the decision making process of fishers facing such competition while operating on a patch. Using optimal foraging theory as the underlying hypothesis, we determined that the probability captains left an area decreases with increasing fishing success whereas, in presence of competition from odontocete whales, it increases. Our study provides strong support that fishers behave as optimal foragers in this specific fishery. Considering that captains are optimal foragers and thus aim at maximising the exploitation of the resources, we highlight possible risks for the long-term sustainability of the local ecosystems