Fishing behaviours and fisher effect in decision-making processes when facing depredation by marine predators

• Published in: Fisheries Management and Ecology
• Main Authors: Janc, Anaïs, Guinet, Christophe, Pinaud, David, Richard, Gaétan, Monestiez, Pascal, Tixier, Paul
• Other Authors: Centre d'Études Biologiques de Chizé - UMR 7372 (CEBC), Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne), Biostatistique et Processus Spatiaux (BioSP), Institut National de la Recherche Agronomique (INRA), Deakin University Burwood
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2021
• Subjects: experience; individual perceptions; optimal foraging theory; skipper behaviour; sustainability of fish stocks; whale– fisheries interactions; [SDE]Environmental Sciences; Antarctic; Antarc*; Orca; Orcinus orca; Physeter macrocephalus
• Online Access: https://hal.archives-ouvertes.fr/hal-02309602; https://doi.org/10.1111/fme.12503

International audience Fishers aim to optimise cost– benefit ratios of their behaviour when exploiting re-sources. Avoidance of interactions with marine predators (i.e. their feeding on catches in fishing gear, known as depredation) has recently become an important component of their decisions. How fishers minimise these interactions whilst maximising fishing success is poorly understood. This issue is addressed in a sub- Antarctic, long- line fish-ery confronted with extensive depredation by sperm whales Physeter macrocephalus and killer whales Orcinus orca by examining a 15- year data set. Whereas a broad range of behaviours was identified from spatio- temporal and operational descriptors, none combined high fishing success with low frequency of interactions. With experience, fishers favoured exploitation of productive patches with high frequencies of interac-tions over avoidance behaviours. Such decisions, although potentially optimal in the short term, are likely to intensify pressures on fish stocks and impact depredating whales. Therefore, the present study provides additional evidence to inform manage-ment decisions pertaining to the coexistence between fisheries and marine predators.