Mercury bioaccumulation along food webs in temperate aquatic ecosystems colonized by aquatic macrophytes in south western France

• Published in: Ecotoxicology and Environmental Safety
• Main Authors: Gentès, Sophie, Maury-Brachet, Régine, Guyoneaud, Rémy, Monperrus, Mathilde, Andre, Jean-Marc, Davail, Stéphane, Legeay, Alexia
• Other Authors: Environnements et Paléoenvironnements OCéaniques (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École pratique des hautes études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Institut des sciences analytiques et de physico-chimie pour l'environnement et les materiaux (IPREM), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Pau et des Pays de l'Adour (UPPA), Laboratoire de l'intégration, du matériau au système (IMS), Université Sciences et Technologies - Bordeaux 1-Institut Polytechnique de Bordeaux-Centre National de la Recherche Scientifique (CNRS), Ecole Nationale Supérieure de Cognitique (ENSC), Institut Polytechnique de Bordeaux, Université de Pau et des Pays de l'Adour (UPPA), UMR 5805 Environnements et Paléoenvironnements Océaniques et Continentaux (EPOC)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2013
• Subjects: Freshwater lake; Invertebrates; Fish; Mercury; Trophic guild; Stable isotope; envir; geo; Anguilla anguilla
• Online Access: https://doi.org/10.1016/j.ecoenv.2013.02.001; https://hal.archives-ouvertes.fr/hal-01702559

International audience Mercury (Hg) is considered as an important pollutant for aquatic systems as its organic form, methylmercury (MeHg), is easily bioaccumulated and bioamplified along food webs. In various ecosystems, aquatic periphyton associated with macrophyte was identified as an important place for Hg storage and methylation by microorganisms. Our study concerns temperate aquatic ecosystems (South Western France) colonized by invasive macrophytes and characterized by high mercury methylation potentials. This work establishes original data concerning Hg bioaccumulation in organisms (plants, crustaceans, molluscs and fish) from five contrasting ecosystems. For low trophic level species, total Hg (THg) concentrations were low (from 277 2 ng THg g À 1 dw in asiatic clam Corbicula fluminea to 418 7 114 ng THg g À 1 dw in crayfish Procambarus clarkii). THg concentrations in some carnivorous fish (high trophic level) were close to or exceeded the International Marketing Level (IML) with values ranging from 10497 220 ng THg g À 1 dw in pike perch muscle (Sander lucioperca) to 3910 7 1307 ng THg g À 1 dw in eel muscle (Anguilla Anguilla). Trophic levels for the individuals were also evaluated through stable isotope analysis, and linked to Hg concentrations of organisms. A significant Hg biomagnification (r 2 ¼ 0.9) was observed in the Aureilhan lake, despite the absence of top predator fish. For this site, Ludwigia sp. periphyton, as an entry point of Hg into food webs, is a serious hypothesis which remains to be confirmed. This study provides a first investigation of Hg transfer in the ecosystems of south western France and allows the assessment of the risk associated with the presence of Hg in aquatic food webs.