Chemical contaminants (trace metals, persistent organic pollutants) in albacore tuna from western Indian and south-eastern Atlantic Oceans: Trophic influence and potential as tracers of populations

• Published in: Science of The Total Environment
• Main Authors: Chouvelon, Tiphaine, Brach-Papa, Christophe, Auger, Dominique, Bodin, Nathalie, Bruzac, Sandrine, Crochet, Sylvette, Degroote, Maxime, Hollanda, Stephanie, Hubert, Clarisse, Knoery, Joël, Munschy, Catherine, Puech, Alexis, Rozuel, Emmanuelle, Thomas, Bastien, West, Wendy, Bourjea, Jérôme, Nikolic, Natacha
• Other Authors: Laboratoire Biogéochimie des Contaminants Métalliques (LBCM), Biogéochimie et Ecotoxicologie (BE), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Laboratoire Environnement Ressources Provence Azur Corse (LERPAC), LITTORAL (LITTORAL), 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), Seychelles Fishing Authority (SFA) (SFA), Université des Seychelles, Laboratoire Biogéochimie des Contaminants Organiques (LBCO), Délégation de La Réunion, Department of Agriculture, Fisheries and Forestry ( DAFF )
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2017
• Subjects: Bioaccumulation; biscay northeast atlantic; enhanced bioaccumulation; feeding ecology; Inorganic elements; Intrinsic markers; marine food webs; mercury concentrations; merluccius-merluccius; Organic contaminants; organochlorine compounds; polychlorinated-biphenyls; stable-isotope analysis; Stable isotopes; thunnus-alalunga; Top predator; [SDE.BE]Environmental Sciences/Biodiversity and Ecology; [SDE.MCG]Environmental Sciences/Global Changes; [SDV.EE.ECO]Life Sciences [q-bio]/Ecology; environment/Ecosystems; Indian; Northeast Atlantic
• Online Access: https://hal.umontpellier.fr/hal-01928683; https://doi.org/10.1016/j.scitotenv.2017.04.048

International audience Albacore tuna (Thunnus alalunga) is a highly commercial fish species harvested in the world's Oceans. Identifying the potential links between populations is one of the key tools that can improve the current management across fisheries areas. In addition to characterising populations' contamination state, chemical compounds can help refine foraging areas, individual flows and populations' structure, especially when combined with other intrinsic biogeochemical (trophic) markers such as carbon and nitrogen stable isotopes. This study investigated the bioaccumulation of seven selected trace metals - chromium, nickel, copper (Cu), zinc (Zn), cadmium (Cd), mercury (Hg) and lead - in the muscle of 443 albacore tunas, collected over two seasons and/or years in the western Indian Ocean (WIO: Reunion Island and Seychelles) and in the south-eastern Atlantic Ocean (SEAO: South Africa). The main factor that explained metal concentration variability was the geographic origin of fish, rather than the size and the sex of individuals, or the season/year of sampling. The elements Cu, Zn, Cd and Hg indicated a segregation of the geographic groups most clearly. For similar sized-individuals, tunas from SEAO had significantly higher concentrations in Cu, Zn and Cd, but lower Hg concentrations than those from WIO. Information inferred from the analysis of trophic markers (δ13C, δ15N) and selected persistent organic pollutants, as well as information on stomach contents, corroborated the geographical differences obtained by trace metals. It also highlighted the influence of trophic ecology on metal bioaccumulation. Finally, this study evidenced the potential of metals and chemical contaminants in general as tracers, by segregating groups of individuals using different food webs or habitats, to better understand spatial connectivity at the population scale. Limited flows of individuals between the SEAO and the WIO are suggested. Albacore as predatory fish also provided some information on environmental and food ...