5. How does climate change influence mercury in the Arctic environment and in biota?

The recent Snow, Water, Ice, and Permafrost in the loss of multi-year sea ice in the marine environment is the Arctic (SWIPA) assessment concluded that the climate in having profound ecological effects (Post et al., 2013), and many the Arctic is moving towards a new state, and that although of those effects are not relevant to Arctic freshwater lakes. [...] The destabilization and slumping of (Stokes et al., 2007; Milner et al., 2017), increasing evaporation permafrost is releasing sediment to downstream lakes and and thermokarst development have led to dramatic reductions waterways as well as to the Arctic Ocean from coastal erosion in the number and surface area of lakes and ponds in non- (Lantuit and Pollard, 2008; Kokelj et al., 2015; Lewkowicz a. [...] In the western Canadian Arctic, is abundant and widely distributed in Arctic surface waters, the timing of stream discharge is changing, with greater and the quality of this terrestrial DOM is highly different flow in winter (Déry et al., 2009; Spence et al., 2014) and compared to DOM produced within the lakes. [...] The deposition is dependent on the stability of one of the most widely documented impacts of climate change the atmosphere, wind speed, and surface properties (Skov et al., on ecosystems (Post et al., 2009; Wassmann et al., 2011; Pecl et al., 2006); thus, the Hg distribution between atmosphere and land 2017). [...] At the same time, local wildfires are a lake outburst floods are responsible for between 5% and 10% of source of Hg to Subarctic Canadian lakes (Pelletier et al., 2020) the river discharge in years when they occur, but between 15% but represent less than 5% of the total Hg deposition to the and 31% of the Hg export (Rigét et al., 2011b; Søndergaard et al., Canadian High Arctic during the peak fire.