Farmed bivalve loss due to seabream predation in the French Mediterranean Prevost Lagoon

• Published in: Aquaculture Environment Interactions
• Main Authors: Richard, Marion, Forget, Fabien, Mignucci, Alexandre, Mortreux, Serge, Le Gall, Patrick, Callier, Myriam D., Weise, Andrea M., McKindsey, Christopher W., Bourjea, Jérôme
• Other Authors: Centre de recherche en neurosciences de Lyon - Lyon Neuroscience Research Center (CRNL), Centre National de la Recherche Scientifique (CNRS)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université de Lyon-Université Jean Monnet Saint-Étienne (UJM)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon, MARine Biodiversity Exploitation and Conservation (UMR MARBEC), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Institut de Recherche pour le Développement (IRD Bolivie ), Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2020
• Subjects: Sparus aurata; Mytilus galloprovincialis; Size; Crassostrea gigas; Acoustic telemetry; Mussel; Oyster; Shellfish culture; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDE.MCG]Environmental Sciences/Global Changes
• Online Access: https://hal.umontpellier.fr/hal-03411061; https://doi.org/10.3354/aei00383

WOS:000604300500001 International audience Bivalve predation by seabream has been observed worldwide and is a major concern for bivalve farmers. Farmed bivalve-seabream interactions must be better understood to ensure the sustainability of bivalve aquaculture. The objectives of this study were to characterize gilthead seabream Sparus aurata presence in a bivalve farm in Prevost Lagoon (Mediterranean Sea) using acoustic telemetry and to evaluate monthly losses of mussels Mytilus galloprovincialis and oysters Crassostrea gigas due to seabream predation over an 18 mo period inside the farm and at an unprotected experimental platform. Large (281 to 499 mm TL) seabream were more commonly detected in the bivalve farm than were small (200 to 280 mm TL) seabream. In contrast to small seabream, 90% of large seabream returned to and spent extended periods in the study area the following year, suggesting inter-annual site fidelity for large fish that used the bivalve farm as a feeding site. Signs of predation were observed on mussels and oysters throughout the year at the unprotected experimental platform. Farmers noted losses in the farm from April to September. Maximal losses (90 to 100%) were observed post-oyster ‘sticking’ and mussel socking. Despite the deployment of nets as mechanical protection to reduce predation, oyster losses represented 28% of the annual value of oysters sold while mussel losses were estimated at ca. 1%. These results suggest that bivalves must be protected by nets throughout the year to avoid predation, particularly post-handling. A collaboration between shellfish farmers and fishermen could be a sustainable solution for bivalve farming, by regularly fishing for seabream in farms, between tables and inside protective nets.