Seasonal migration, site fidelity, and population structure of European seabass ( Dicentrarchus labrax )

• Published in: ICES Journal of Marine Science
• Main Authors: de Pontual, Helene, Heerah, Karine, Goossens, Jolien, Garren, François, Martin, Stephane, Le Ru, Loic, Le Roy, Didier, Woillez, Mathieu
• Other Authors: Dynamique et durabilité des écosystèmes : de la source à l’océan (DECOD), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut Agro Rennes Angers, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), France Energies Marines Brest, Marine Biology Research Group, Universiteit Gent = Ghent University (UGENT), Unité Sciences et Technologies Halieutiques (STH), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2023
• Subjects: large-scale electronic tagging; movement ecology; spawning site fidelity; stock structure; temperature; biologging; depth; Dicentrarchus labrax; DST data storage tag; European sea bass; geolocation model; [SDE]Environmental Sciences; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; Northeast Atlantic
• Online Access: https://hal.inrae.fr/hal-04150655; https://doi.org/10.1093/icesjms/fsad087

International audience Abstract Large-scale electronic tagging is a very powerful tool to study how fish movements and migrations shape the internal dynamics of populations. This knowledge, crucial for improving fishery management, was still limited for the European seabass, whose stocks in the Northeast Atlantic have declined drastically over the last decade. To better understand the species ecology and the spatio-temporal structure of the population, we tagged seabass in the North Sea, the English Channel, and the Bay of Biscay, from 2014 to 2016. Out of 1220 deployed DSTs, 482 have been recovered by November 2022. Approximately half of them included a period of potential spawning migration. Reconstructed trajectories confirmed seabass to be a partial migratory species, as individuals exhibited either long-distance migrations or residence. Most migrants exhibited fidelity to summer feeding areas and winter spawning areas. Our dataset enriches the knowledge of seabass biological traits (e.g. temperature and depth ranges, vulnerability to predation and fishing). Our results suggest a spatial structure of the Atlantic population that differs from the stock structure currently considered for assessment and management. The consequences should be explored at both the European level and by regional managers involved in conservation outcomes.