Benevolent & Vicious Interactions: Untangling the processes linking mercury, sulphur, and water in peatlands impacted by humans

Mercury is a global pollutant that can cause adverse health effects in humans through the accumulation of methylmercury in tissue, commonly referred as Minamata Disease. Methylmercury is a bioaccumulating neurotoxin that is commonly produced in wetland environments, chiefly peatlands. Peatlands are deeply anoxic wetland systems that are dominated by organic soils and typically nutrient poor conditions. It is this combination of the lack of oxygen, low nutrients and abundance of carbon that provides suitable conditions to produce methylmercury. The production of methylmercury depends on the interactions and feedbacks between mercury, water and sulphur. Human activities, such as wastewater treatment, acid rain and forestry, disrupt these linkages, altering the cycling and export of mercury. Yet, the timing, magnitude and directionality of these human induced changes to mercury cycling remains unknown. Using experimental results from three field-scale ecosystem manipulation studies focused-on wastewater treatment, acid rain and forestry, I elucidate the complicated interactions of mercury cycling and export when humans disrupt peatland ecosystems.