title: Mercury bioaccumulation along food webs in temperate aquatic ecosystems colonized by aquatic macrophytes in south western France.
abstract: 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 27±2ngTHgg(-1)dw in asiatic clam Corbicula fluminea to 418±114ngTHgg(-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 1049±220ngTHgg(-1)dw in pike perch muscle (Sander lucioperca) to 3910±1307ngTHgg(-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)= 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.
authors: Equipe Environnement et Microbiologie, UMR IPREM5254, Université de Pau et des Pays de l'Adour, Bâtiment IBEAS, BP1155 F-64013 Pau Cedex, France.
authors: Sophie
authors: S
authors: Gentès
authors: Régine
authors: R
authors: Maury-Brachet
authors: Rémy
authors: R
authors: Guyoneaud
authors: Mathilde
authors: M
authors: Monperrus
authors: Jean-Marc
authors: JM
authors: André
authors: Stéphane
authors: S
authors: Davail
authors: Alexia
authors: A
authors: Legeay
mesh_terms: D000818:Animals; D004784:Environmental Monitoring; D005399:Fishes / Q000378:metabolism*; D020387:Food Chain; D005602:France; D019015:Geologic Sediments / Q000737:chemistry; D058865:Introduced Species; D007448:Invertebrates / Q000737:chemistry* / Q000378:metabolism*; D060106:Lakes; D008628:Mercury / Q000032:analysis / Q000378:metabolism*; D009132:Muscles / Q000737:chemistry; D010944:Plants / Q000737:chemistry* / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D014874:Water Pollutants, Chemical; D008628:Mercury