Plenary- Global change and biogeochemical mercury cycling

Humans release mercury (Hg) into all Earth ecosystems where a fraction is converted to a bioaccumulative and neurotoxic form— methylmercury (methyl-Hg). Methyl-Hg containing freshwater and marine fish are the main pathway of Hg to humans. Exposure to methyl-Hg increases the risk of neurological and cardiovascular disease with an estimated annual global societal cost of $117 billion. The UNEP Minamata Convention on Mercury aims to curb Hg releases to the environment and is accompanied by global Hg monitoring efforts to track success in mitigation of contamination. A challenge facing research and policy communities is that Hg dispersion, transport, reactivity, speciation, and methyl-Hg biomagnification, are physical, chemical, biological, and ecological processes sensitive to ongoing global change, including climate change. In this synthesis and plenary, we discuss examples of global change impacts on biogeochemical Hg cycling.