Mercury contamination of Arctic Marine BiotA: sources, levels and impacts – MAMBA

The Arctic is an extremely sensitive region threatened by major and increasing pollution risks. Among them, mercury (Hg), which can have high impacts on organisms and populations, has raised major environmental concerns. These concerns are especially high as Hg levels are substantial and should continue to increase in the Arctic marine environment. Although there has been an international effort led over the last decades to characterize Hg concentrations, temporal trends and toxicological effects, some major gaps remain to fully grasp the threats posed by Hg to the Arctic wildlife as well as the risks associated with increasing levels. Relying on a large scale approach and using seabirds as bioindicators, I propose to provide a comprehensive understanding of the Hg contamination of Arctic marine food-webs. To this end, this project will use a unique international, pan-Arctic sampling network allowing the collaborative collection of tissues on various seabird species all around the Arctic. It will first map the spatial distribution of Hg in food webs around the Arctic and define areas requiring protection. Second, it will help identify and understand the sources and pathways of this Hg contamination, both inside the Arctic (where is Hg the most bioavailable in marine ecosystems and where does it come from?) and from outside the Arctic (how are migratory organisms exposed to Hg once they have left the Arctic?). Finally, this project will provide new knowledge about large-scale impacts of Hg, alone or in combination to environmental conditions, on the ecophysiology, energetics and ultimately distribution of Arctic marine top-predators. By combining inputs from different disciplines (ecotoxicology, environmental and analytical chemistry, biogeography, energetics, ecophysiology) and state-of-the-art methodologies, this project will address international priorities regarding the impacts of global change on Polar Regions and the conservation of the world’s biodiversity.