Does temporal variation of mercury levels in Arctic seabirds reflect changes in global environmental contamination, or a modification of Arctic marine food web functioning?

摘要: Studying long-term trends of contaminants in Arctic biota is essential to better understand impacts anthropogenic activities and climate change on the exposure sensitive species marine ecosystems. We concurrently measured temporal changes (2006-2014) mercury (Hg) contamination little auks (Alle alle; most abundant seabird) their major zooplankton prey (Calanoid copepods, Themisto libellula, Gammarus spp.). found an increasing food-chain East Greenland during summer over last decade. More specifically, bird (determined by body feather analyses) has increased at a rate 3.4% per year. Conversely, Hg winter northwest Atlantic head decreased study period (at 1.5% year), although concentrations remained consistently higher than summer. By combining levels birds isotopic analyses, our results demonstrate that inter-annual variations reflect contamination, rather reorganization food web modification seabird trophic ecology. They therefore underline value auks, seabirds general, as bio-indicators environmental contamination.