Assessing net methylmercury potential in drained basins in Old Crow Flats, Yukon

Permafrost lowlands with lakes and drained lake basins represent approximately 20% of the circumpolar North’s land surface. In these landscapes, generations of drained lake basins accumulate carbon over hundreds and thousands of years and, as in other permafrost landscapes, this stored carbon may be associated with mercury (Hg). Accelerated landscape changes in permafrost environments may have implications for Hg cycling as changing terrain conditions can influence Hg methylation - the transformation of inorganic Hg to methylmercury(MeHg), which bioaccumulates and is a neurotoxin. Drained lake basins include a range of wetland dry environments that host different microbial communities and are likely to have different Hg methylation potential. This study examines the net MeHg production potential in drained lake basins of Old Crow Flats (OCF), Yukon. OCF is a vast thermokarst lowland underlain by continuous permafrost and is a crucial part of the Vuntut Gwitchin First Nation (VGFN) traditional territory.