Freshwater protected areas: an effective measure to reconcile conservation and exploitation of the threatened European eels (Anguilla anguilla)?

• Published in: Ecology of Freshwater Fish
• Main Authors: Cucherousset, Julien, Paillisson, Jean-Marc, Carpentier, Alexandre, Thoby, V., Damien, J.-P., Eybert, Marie-Christine, Feunteun, Eric, Robinet, T.
• Other Authors: Ecosystèmes, biodiversité, évolution Rennes (ECOBIO), Université de Rennes (UR)-Institut Ecologie et Environnement - CNRS Ecologie et Environnement (INEE-CNRS), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Biologie des organismes marins et écosystèmes (BOME), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Centre de Recherche sur les Ecosystèmes Littoraux Anthropisés (CRELA), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2007
• Subjects: Anguilla anguilla; spawners production; protected area; habitat restoration; coastal freshwater marsh; ISSN: 0906-6691; [SDV.EE]Life Sciences [q-bio]/Ecology; environment
• Online Access: https://hal.science/hal-00214227; https://doi.org/10.1111/j.1600-0633.2007.00247.x

International audience For decades, the European eel Anguilla anguilla (L.) population has been declining strongly despite several management attempts, so additional experiments need to be conducted on management measures. The use of freshwater protected areas has been advocated but their efficiency has never been assessed. In this study, we investigated whether the population structure and the silver eel (mature migrating stage) production differ in fished and protected areas within a marsh wetland (Briere, 7000 ha, Northwest France), using an intensive biological study (electrofishing and trapping) and a survey of the traditional fishery (licenses, questionnaires and creel surveys). First, we found that fishermen mainly targeted > 320-mm yellow eels (sedentary stage) using pots and square dipping nets and that harvest by fishermen was highly variable at different locations in the study area. Secondly, we found differences in the size-class structures and mortality rates between protected and fished areas. Mortality rates of eels > 320 mm was positively correlated with harvest by fishermen. Furthermore, the proportion of potentially migrating eels in the total population was found to be higher in the protected areas than in fished areas (6.38% vs. 1.42%, respectively). Thirdly, we found that protected areas potentially produce 8.4% of the total silver eel production whereas they only account for 2.4% of the aquatic habitat area. We estimated that a size adjustment of protected areas to 31.1% with maintaining the current fishery would produce 50% of the potential silver eel of a fully protected marsh. Protection of freshwater areas appears to be a promising management measure and a constructive consensual way to integrate the patrimonial and societal value of the traditional fishery and the international management plans for European eels. Furthermore, freshwater protective measures can be an effective local solution if they are integrated into the framework of freshwater biodiversity management and ...