| Abstract Title: | Multi-year (2007-2017) variations in mercury (Hg) fluxes from small High Arctic rivers impacted by permafrost degradation and disturbance |
| Presenter Name: | Jane Kirk |
| Company/Institution: | Environment and Climate Change Canada |
| Session: | Mercury in Polar Ecosystems |
| Day and Session: | Tuesday 26th July - Session Two |
| Start Time: | 10:00 UTC |
| Co-Authors: | Jane Kirk,Scott Lamoureux,Michael Pope,Melissa Lafrenire,Igor Lehnherr,Casey Beel,Vincent St. Louis,Derek Muir |
Abstract Information :
Mercury (Hg) transport dynamics and multiyear fluxes in response to climate and permafrost degradation were investigated in paired High Arctic catchments located at the Cape Bounty Arctic Watershed Observatory, Melville Island, Nunavut. We use long-term (2007-2017), high frequency (every 3 hours during hydrologically important events) to demonstrate significant diel and inter-annual variations in watershed total-Hg (THg) concentrations and fluxes in response to climate driven near-surface permafrost disturbance and inter-annual variability in river discharge. Further, we utilized the consistent and strong, significant linear relationships observed between THg concentrations, total suspended solids (TSS) concentrations, and fractions of organic carbon to improve the accuracy of modelled annual THg exports over more commonly used, conventional interpolation methods. The diel and seasonal timing and intensity of runoff during snow melt and infrequent, late season rain events was a dominant driver of THg and MeHg concentrations and the annual THg flux. Together our results indicate that Hg transport from Arctic watersheds will increase with further permafrost disturbance and rainfall in association with TSS transport to downstream aquatic systems.
