Commercial fishing patterns influence odontocete whale-longline interactions in the Southern Ocean

• Published in: Scientific Reports
• Main Authors: Tixier, Paul, Burch, Paul, Richard, Gaëtan, Olsson, Karin, Welsford, Dirk, Lea, Mary-Anne, Hindell, Mark, Guinet, Christophe, Janc, Anaïs, Gasco, Nicolas, Duhamel, Guy, Villanueva, Maria Ching, Suberg, Lavinia, Arangio, Rhys, Söffker, Marta, Arnould, John
• Other Authors: School of Life and Environmental Sciences (Burwood Campus) Australia, Deakin University Burwood, Commonwealth Scientific and Industrial Research Organisation (CSIRO) (CSIRO), Commonwealth Scientific and Industrial Research Organisation (CSIRO), 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), Centre for Environment, Fisheries & Aquaculture Science UK, Department of Zoology, Tel Aviv University (TAU), Australian Antarctic Division (AAD), Australian Government, Department of the Environment and Energy, Institute for Marine and Antarctic Studies Hobart (IMAS), University of Tasmania Hobart, Australia (UTAS), Département Milieux et Peuplements Aquatiques, Muséum national d'Histoire naturelle (MNHN), Unité Sciences et Technologies Halieutiques (STH), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Coalition of Legal Toothfish Operators Australia (COLTO), School of Environmental and Life Sciences - SELS (Callaghan, Australia), University of Newcastle Callaghan, Australia (UoN), 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 2019
• Subjects: [SDE]Environmental Sciences; Killer Whale; Orca; Orcinus orca; Patagonian Toothfish; Physeter macrocephalus; Southern Ocean; Sperm whale; Killer whale
• Online Access: https://hal.science/hal-02032705; https://doi.org/10.1038/s41598-018-36389-x

International audience The emergence of longline fishing around the world has been concomitant with an increase indepredation-interactions by odontocete whales (removal of fish caught on hooks), resulting insubstantial socio-economic and ecological impacts. The extent, trends and underlying mechanismsdriving these interactions remain poorly known. Using long-term (2003–2017) datasets from sevenmajor Patagonian toothfish (Dissostichus eleginoides) longline fisheries, this study assessed the levelsand inter-annual trends of sperm whale (Physeter macrocephalus) and/or killer whale (Orcinus orca)interactions as proportions of fishing time (days) and fishing area (spatial cells). The role of fishingpatterns in explaining between-fisheries variations of probabilities of odontocete interactions wasinvestigated. While interaction levels remained globally stable since the early 2000s, they variedgreatly between fisheries from 0 to >50% of the fishing days and area. Interaction probabilities wereinfluenced by the seasonal concentration of fishing effort, size of fishing areas, density of vessels, theirmobility and the depth at which they operated. The results suggest that between-fisheries variationsof interaction probabilities are largely explained by the extent to which vessels provide whales withopportunities for interactions. Determining the natural distribution of whales will, therefore, allowfishers to implement better strategies of spatio-temporal avoidance of depredation.