title: 210Po and 210Pb trophic transfer within the phytoplankton-zooplankton-anchovy/sardine food web: a case study from the Gulf of Lion (NW Mediterranean Sea).
abstract: The transfer of (210)Po and (210)Pb in the food web of small pelagic fishes (from phytoplankton and zooplankton to anchovy Engraulis encrasicolus and sardine Sardina pilchardus) is investigated in the Gulf of Lion (GoL). We present original data of (210)Po and (210)Pb activity concentrations, C and N stable isotope ratios, measured (i) from different size classes of phytoplankton and zooplankton during spring and winter in different environments of the GoL, and (ii) in two fish species. Significant spatial patterns based on (210)Po, (210)Pb activity concentrations and (210)Po/(210)Pb ratios in the different plankton size classes are evidenced by hierarchical clustering, both in spring and winter. This variability, also observed for C and N stable isotopes ratios, is connected to local specific pelagic habitats and hydrodynamics. The sampling strategy suggests that (210)Po bioaccumulation in the GoL remains at a constant level from the first (dominated by phytoplankton) to the second trophic level (zooplankton), while (210)Pb bioaccumulation shows an increase in winter. Based on stable N isotope ratios and (210)Po activity concentrations measured in anchovies and sardines, we evidence (210)Po bio-magnification along the trophic food web of these two planktivorous pelagic fishes.
authors.affiliation: CEREGE UM34, Aix-Marseille Université, CNRS UMR7330, 13545 Aix en Provence, France; IRD, LTHE, F-38000 Grenoble, France. Electronic address: emilie.strady@ird.fr.
authors.forename: Emilie
authors.initials: E
authors.lastname: Strady
authors.affiliation: Institut Méditerranéen d'Océanologie (MIO), UM 110, Aix-Marseille Université, Université de Toulon, CNRS/INSU/IRD, Campus de Luminy, case 901, 13288 Marseille, France.
authors.forename: Mireille
authors.initials: M
authors.lastname: Harmelin-Vivien
authors.affiliation: IFREMER-Nantes, France.
authors.forename: Jean François
authors.initials: JF
authors.lastname: Chiffoleau
authors.affiliation: CEREGE UM34, Aix-Marseille Université, CNRS UMR7330, 13545 Aix en Provence, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Veron
authors.affiliation: IFREMER-Nantes, France.
authors.forename: Jacek
authors.initials: J
authors.lastname: Tronczynski
authors.affiliation: CEREGE UM34, Aix-Marseille Université, CNRS UMR7330, 13545 Aix en Provence, France.
authors.forename: Olivier
authors.initials: O
authors.lastname: Radakovitch
mesh_terms: D000818:Animals; D005399:Fishes / Q000378:metabolism*; D020387:Food Chain; D005602:France; D007856:Lead Radioisotopes / Q000378:metabolism*; D008522:Mediterranean Sea; D010839:Phytoplankton / Q000378:metabolism*; D011059:Polonium / Q000378:metabolism*; D012621:Seasons; D014875:Water Pollutants, Radioactive / Q000378:metabolism*; D015048:Zooplankton / Q000378:metabolism*
chemical_list: D007856:Lead Radioisotopes; D014875:Water Pollutants, Radioactive; D011059:Polonium
keywords: (210)Pb; (210)Po; Mediterranean Sea; Pelagic fishes; Phytoplankton; Zooplankton