Enhanced bioaccumulation of mercury in deep-sea fauna from the Bay of Biscay (north-east Atlantic) in relation to trophic positions identified by analysis of carbon and nitrogen stable isotopes

• Published in: Deep Sea Research Part I: Oceanographic Research Papers
• Main Authors: Chouvelon, Tiphaine, Spitz, Jérôme, Caurant, Florence, Mèndez-Fernandez, Paula, Autier, Julien, Lassus-Débat, Aurélie, Chappuis, Alexis, Bustamante, Paco
• Other Authors: LIttoral ENvironnement et Sociétés - UMR 7266 (LIENSs), Institut national des sciences de l'Univers (INSU - CNRS)-La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2012
• Subjects: stable isotope; trophic transfer; fish; mollusc; crustaceans; marine environment; Metal; [SDV.TOX.ECO]Life Sciences [q-bio]/Toxicology/Ecotoxicology; North East Atlantic
• Online Access: https://hal.science/hal-00694521; https://hal.science/hal-00694521/document; https://hal.science/hal-00694521/file/Chouvelon_et_al._2012_DSR_part_I.pdf; https://doi.org/10.1016/j.dsr.2012.02.010

International audience The Bay of Biscay (north-east Atlantic) is an open marine ecosystem of particular concern in current European environmental policies. Indeed, it supports both a high biological diversity and numerous anthropogenic activities such as important fisheries. For the first time, stable isotope analyses (SIA) of carbon and nitrogen and analysis of total mercury (T-Hg) concentrations in the muscle (edible flesh) were performed on adult stages of a wide range of species (i.e., 120 species) from various taxa and various habitats of this ecosystem. Concentrations of this non-essential metal, toxic to all living organisms, ranged from 39 to 5074 ng.g-1 dry weight. Calculations of species' trophic positions (TPs) through SIA revealed a limited effect of TP in explaining Hg bioaccumulation by high trophic level consumers in particular. On the contrary, our results suggest an important role of habitat and/or feeding zone, which strongly influence muscle Hg bioaccumulation. Deep-sea fish species effectively presented the highest Hg concentrations. Possible interactions between biological factors (e.g., age of deep-sea organisms) and bioavailability of the metal in the deep-sea environment are discussed to explain such enhanced bioaccumulation of Hg by deep-sea fauna in the Bay of Biscay. This study also highlights a potential risk for human health when deep-sea fish are consumed frequently.