title: Trophic ecology influence on metal bioaccumulation in marine fish: Inference from stable isotope and fatty acid analyses.
abstract: The link between trophic ecology and metal accumulation in marine fish species was investigated through a multi-tracers approach combining fatty acid (FA) and stable isotope (SI) analyses on fish from two contrasted sites on the coast of Senegal, one subjected to anthropogenic metal effluents and another one less impacted. The concentrations of thirteen trace metal elements (As, Cd, Co, Cr, Cu, Fe, Li, Mn, Ni, Pb, Sn, U, and Zn) were measured in fish liver. Individuals from each site were classified into three distinct groups according to their liver FA and muscle SI compositions. Trace element concentrations were tested between groups revealing that bioaccumulation of several metals was clearly dependent on the trophic guild of fish. Furthermore, correlations between individual trophic markers and trace metals gave new insights into the determination of their origin. Fatty acids revealed relationships between the dietary regimes and metal accumulation that were not detected with stable isotopes, possibly due to the trace metal elements analysed in this study. In the region exposed to metallic inputs, the consumption of benthic preys was the main pathway for metal transfer to the fish community while in the unaffected one, pelagic preys represented the main source of metals. Within pelagic sources, metallic transfer to fish depended on phytoplankton taxa on which the food web was based, suggesting that microphytoplankton (i.e., diatoms and dinoflagellates) were a more important source of exposition than nano- and picoplankton. This study confirmed the influence of diet in the metal accumulation of marine fish communities, and proved that FAs are very useful and complementary tools to SIs to link metal accumulation in fish with their trophic ecology.
authors.affiliation: Laboratoire des Sciences de l'Environnement Marin (LEMAR), UMR 6539 CNRS/UBO/IRD/IFREMER, BP 70, 29280 Plouzané, France. Electronic address: gael.lecroizier@univ-brest.fr.
authors.forename: Gaël
authors.initials: G
authors.lastname: Le Croizier
authors.affiliation: Laboratoire des Sciences de l'Environnement Marin (LEMAR), UMR 6539 CNRS/UBO/IRD/IFREMER, BP 70, 29280 Plouzané, France.
authors.forename: Gauthier
authors.initials: G
authors.lastname: Schaal
authors.affiliation: Laboratoire des Sciences de l'Environnement Marin (LEMAR), UMR 6539 CNRS/UBO/IRD/IFREMER, BP 70, 29280 Plouzané, France.
authors.forename: Régis
authors.initials: R
authors.lastname: Gallon
authors.affiliation: Centre de Recherches Océanographiques de Dakar-Thiaroye (CRODT/ISRA), BP 2241, Dakar, Sénégal.
authors.forename: Massal
authors.initials: M
authors.lastname: Fall
authors.affiliation: Laboratoire des Sciences de l'Environnement Marin (LEMAR), UMR 6539 CNRS/UBO/IRD/IFREMER, BP 70, 29280 Plouzané, France.
authors.forename: Fabienne
authors.initials: F
authors.lastname: Le Grand
authors.affiliation: Laboratoire des Sciences de l'Environnement Marin (LEMAR), UMR 6539 CNRS/UBO/IRD/IFREMER, BP 70, 29280 Plouzané, France.
authors.forename: Jean-Marie
authors.initials: JM
authors.lastname: Munaron
authors.affiliation: Institut Universitaire Européen de la Mer (IUEM), Université de Bretagne Occidentale (UBO), CNRS UMS 3113, 29280 Plouzané, France.
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Rouget
authors.affiliation: Laboratoire d'Océanographie Physique et Spatiale (LOPS), UMR 6523 CNRS/IFREMER/IRD/UBO, BP70, 29280 Plouzané, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Machu
authors.affiliation: Laboratoire des Sciences de l'Environnement Marin (LEMAR), UMR 6539 CNRS/UBO/IRD/IFREMER, BP 70, 29280 Plouzané, France.
authors.forename: François
authors.initials: F
authors.lastname: Le Loc'h
authors.affiliation: Laboratoire des Sciences de l'Environnement Marin (LEMAR), UMR 6539 CNRS/UBO/IRD/IFREMER, BP 70, 29280 Plouzané, France.
authors.forename: Raymond
authors.initials: R
authors.lastname: Laë
authors.affiliation: Laboratoire des Sciences de l'Environnement Marin (LEMAR), UMR 6539 CNRS/UBO/IRD/IFREMER, BP 70, 29280 Plouzané, France.
authors.forename: Luis Tito
authors.initials: LT
authors.lastname: De Morais
mesh_terms: D000818:Animals; D004032:Diet; D004784:Environmental Monitoring / Q000379:methods*; D005227:Fatty Acids / Q000378:metabolism*; D005399:Fishes / Q000378:metabolism*; D020387:Food Chain; D007554:Isotopes / Q000032:analysis; D008099:Liver / Q000378:metabolism; D008670:Metals / Q000032:analysis / Q000378:metabolism*; D009132:Muscles / Q000378:metabolism; D012675:Senegal; D013045:Species Specificity; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism*
chemical_list: D005227:Fatty Acids; D007554:Isotopes; D008670:Metals; D014874:Water Pollutants, Chemical
keywords: Biochemical tracers; Contamination; Diet; Senegal; Trace elements; Tropical fish