Paco Bustamante, Claude Belpaire, Michael Ingemann Pedersen, Gregory E. Maes, Elsa Amilhat, Laure Virag, Gustavo Becerra-Jurado, Elisabeth Faliex, Kim Aarestrup, Catherine Boisneau, Javier Lobón-Cerviá, Anthony Acou, Govindan Malarvannan, Eric Feunteun, Alan Walker, Lieven Bervoets, David Righton, Clarisse Boulenger, Niklas Sjöberg, Håkan Wickström, Thomas Trancart, Russell Poole, Adrian Covaci, Paddy Gargan, Bastien Bourillon, Biologie des Organismes et Ecosystèmes Aquatiques (BOREA), Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Sorbonne Université (SU)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU), Patrimoine naturel (PatriNat), Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Office français de la biodiversité (OFB), pôle OFB-INRAE- Agrocampus Ouest-UPPA pour la gestion des migrateurs amphihalins dans leur environnement, AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Université de Pau et des Pays de l'Adour (UPPA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Office français de la biodiversité (OFB), INBO - Research Institute for Nature and Forest, Research Institute for Nature and Forest (INBO), University of Antwerp (UA), LIttoral ENvironnement et Sociétés - UMRi 7266 (LIENSs), Université de La Rochelle (ULR)-Centre National de la Recherche Scientifique (CNRS), Institut Universitaire de France (IUF), Ministère de l'Education nationale, de l’Enseignement supérieur et de la Recherche (M.E.N.E.S.R.), Centre de Formation et de Recherche sur les Environnements Méditérranéens (CEFREM), Université de Perpignan Via Domitia (UPVD)-Centre National de la Recherche Scientifique (CNRS), DTU Aqua, National Institute of Aquatic Resources, Technical University of Denmark [Lyngby] (DTU), Cités, Territoires, Environnement et Sociétés (CITERES), Centre National de la Recherche Scientifique (CNRS)-Université de Tours, Unité Expérimentale d'Ecologie et d'Ecotoxicologie Aquatique - U3E (Rennes, France) (U3E ), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Inland Fisheries Ireland, Institute for European Environmental Policy, National Museum of Natural Sciences, Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Faculty of Bioscience Engineering, Department of Biosystems, Division of Gene Technology, Université Catholique de Louvain = Catholic University of Louvain (UCL), Center for Human Genetics, University of Leuven School of Medicine, SCHOOL of MEDICINE [Louvain], Université Catholique de Louvain = Catholic University of Louvain (UCL)-Université Catholique de Louvain = Catholic University of Louvain (UCL), Centre for Sustainable Tropical Fisheries and Aquaculture - Comparative Genomics Centre - College of Science and Engineering, James Cook University, Marine Institute [Ireland], Swedish University of Agricultural Sciences (SLU), Centre for Environment, Fisheries and Aquaculture Science [Lowestoft] (CEFAS), European Project: 212133,EC:FP7:ENV,FP7-ENV-2007-1,EELIAD(2008), Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université des Antilles (UA), Pôle OFB-INRAE- Agrocampus Ouest-UPPA pour la gestion des migrateurs amphihalins dans leur environnement, AGROCAMPUS OUEST-Université de Pau et des Pays de l'Adour (UPPA)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Office français de la biodiversité (OFB), LIttoral ENvironnement et Sociétés (LIENSs), La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS), Université de Perpignan Via Domitia (UPVD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Danmarks Tekniske Universitet = Technical University of Denmark (DTU), Université de Tours (UT)-Centre National de la Recherche Scientifique (CNRS), James Cook University (JCU), and Centre National de la Recherche Scientifique (CNRS)-Université de Tours (UT)
The European eel is critically endangered. Although the quality of silver eels is essential for their reproduction, little is known about the effects of multiple contaminants on the spawning migration and the European eel management plan does not take this into account. To address this knowledge gap, we sampled 482 silver eels from 12 catchments across Europe and developed methods to assess three aspects of eel quality: muscular lipid content (N = 169 eels), infection with Anguillicola crassus (N = 482), and contamination by persistent organic pollutants (POPs, N = 169) and trace elements (TEs, N = 75). We developed a standardized eel quality risks index (EQR) using these aspects for the subsample of 75 female eels. Among 169 eels, 33% seem to have enough muscular lipids content to reach the Sargasso Sea to reproduce. Among 482 silver eels, 93% were infected by A. crassus at least once during their lifetime. All contaminants were above the limit of quantification, except the 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), Ag and V. The contamination by POPs was heterogeneous between catchments while TEs were relatively homogeneous, suggesting a multi-scale adaptation of management plans. The EQR revealed that eels from Warwickshire were most impacted by brominated flame-retardants and agricultural contaminants, those from Scheldt were most impacted by agricultural and construction activities, PCBs, coal burning, and land use, while Frémur eels were best characterized by lower lipid contents and high parasitic and BTBPE levels. There was a positive correlation between EQR and a human footprint index highlighting the capacity of silver eels for biomonitoring human activities and the potential impact on the suitability of the aquatic environment for eel population health. EQR therefore represents a step forward in the standardization and mapping of eel quality risks, which will help identify priorities and strategies for restocking freshwater ecosystems., The EELIAD project was funded by the European Union FP7 researchprogram on environment (Grant agreement No. GOCE-2008212133, EU-EELIAD 2008-2012).