Sources and sinks of contaminants across northern ecosystems
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Much of our work has focused on the fluxes and transformations of total mercury (THg) and methylated mercury (MeHg) across northern aquatic ecosystems, from headwaters to coastal marine environments. We use both field surveys and experiments with stable isotope additions to quantify rates of MeHg production and loss in different environments. Analyses are conducted using inductively-coupled plasma mass spectrometry (ICP/MS), cold-vapour atomic fluorescence spectroscopy (CVAFS) and direct mercury analyzers (DMA).
Recent collaborations have also examined the fluxes of organic contaminants (perfluoroalkyl substances, flame retardants) across northern watersheds (e.g., MacInnis et al. 2019, Environ. Sci. Technol. 53, 10753-10762.). Current projects within this theme: Evaluating metal mobility in plants and animals near abandoned mine tailings in the Wheaton River Watershed, Yukon (Lead: K. Rorabeck, M.Sc. candidate) Partners: Carcross/Tagish First Nation, Yukon University Towards the development of a community-informed strategy for contaminants research in the Yukon (Lead: Z. Musch, M.Sc. candidate) Partners: Yukon University, Gamberg Consulting Sources and sinks of metal and organic contaminants across the Bennett and Tagish Lake watersheds (Incoming lead: L. Rupke, M.Sc. start May 2026) Partners: Yukon University, Carcross/Tagish First Nation, Taku River Tlingit First Nation, Environment and Climate Change Canada |
Conceptual diagram showing total (THg) and methyl mercury (MeHg) fluxes and transformations across a glaciered watershed (Fig. from St. Pierre et al. 2019, Environ. Sci. Technol.).
Diagram illustrating THg and MeHg by retrogressive thaw slumps in the western Canadian Arctic (from St. Pierre, Zolkos and Shakil et al. 2018, Environ. Sci. Technol.)
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