title: Does temporal variation of mercury levels in Arctic seabirds reflect changes in global environmental contamination, or a modification of Arctic marine food web functioning?
abstract: Studying long-term trends of contaminants in Arctic biota is essential to better understand impacts of anthropogenic activities and climate change on the exposure of sensitive species and marine ecosystems. We concurrently measured temporal changes (2006-2014) in mercury (Hg) contamination of little auks (Alle alle; the most abundant Arctic seabird) and in their major zooplankton prey species (Calanoid copepods, Themisto libellula, Gammarus spp.). We found an increasing contamination of the food-chain in East Greenland during summer over the last decade. More specifically, bird contamination (determined by body feather analyses) has increased at a rate of 3.4% per year. Conversely, bird exposure to Hg during winter in the northwest Atlantic (determined by head feather analyses) decreased over the study period (at a rate of 1.5% per year), although winter concentrations remained consistently higher than during summer. By combining mercury levels measured in birds and zooplankton to isotopic analyses, our results demonstrate that inter-annual variations of Hg levels in little auks reflect changes in food-chain contamination, rather than a reorganization of the food web and a modification of seabird trophic ecology. They therefore underline the value of little auks, and Arctic seabirds in general, as bio-indicators of long-term changes in environmental contamination.
authors.affiliation: Littoral, Environnement et Sociétés (LIENSs), UMR 7266 CNRS - Université La Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle, France. Electronic address: fort.jerome@gmail.com.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Fort
authors.affiliation: Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), UMR 5175 CNRS - Université de Montpellier - Université Paul-Valéry Montpellier - EPHE, 1919 route de Mende, 34293 Montpellier, France; FitzPatrick Institute, DST/NRF Excellence Centre at the University of Cape Town, Rondebosch 7701, South Africa.
authors.forename: David
authors.initials: D
authors.lastname: Grémillet
authors.affiliation: Littoral, Environnement et Sociétés (LIENSs), UMR 7266 CNRS - Université La Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle, France.
authors.forename: Gwendoline
authors.initials: G
authors.lastname: Traisnel
authors.affiliation: Centre d'Ecologie Fonctionnelle et Evolutive (CEFE), UMR 5175 CNRS - Université de Montpellier - Université Paul-Valéry Montpellier - EPHE, 1919 route de Mende, 34293 Montpellier, France.
authors.forename: Françoise
authors.initials: F
authors.lastname: Amélineau
authors.affiliation: Littoral, Environnement et Sociétés (LIENSs), UMR 7266 CNRS - Université La Rochelle, 2 rue Olympe de Gouges, 17000 La Rochelle, France.
authors.forename: Paco
authors.initials: P
authors.lastname: Bustamante
mesh_terms: D000818:Animals; D001110:Arctic Regions; D001717:Birds / Q000378:metabolism*; D046091:Charadriiformes / Q000378:metabolism; D057231:Climate Change; D033342:Copepoda; D004463:Ecology; D017753:Ecosystem; D004784:Environmental Monitoring; D004785:Environmental Pollutants / Q000378:metabolism*; D004787:Environmental Pollution / Q000032:analysis / Q000706:statistics & numerical data; D005241:Feathers / Q000737:chemistry; D020387:Food Chain; D006116:Greenland; D008628:Mercury / Q000032:analysis / Q000378:metabolism*; D012621:Seasons; D015048:Zooplankton / Q000378:metabolism
chemical_list: D004785:Environmental Pollutants; D008628:Mercury
keywords: Arctic; Bio-indicator; Little auk; Metal; Temporal trend; Zooplankton