BE/CBC: Atmospheric Deposition, Transport, Transformations and Bioavailability of Mercury across a Northern Forest Landscape

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This award investigates mercury cycling in a mercury-impacted lake in the Adirondacks of New York, an acid-sensitive forested area with high concentrations of mercury in fish relative to other lake districts in eastern North America.The experimental premise of this research is that canopy processes enhance atmospheric mercury deposition to northern forest ecosystems. The transport and transformation of mercury and the supply of methyl mercury to aquatic biota is controlled by the pathway of deposition, redox-controlled microbial transformations, and landscape characteristics (e.g., vegetation, wetlands, surface waters). Atmospheric deposition of mercury to forest ecosystems is enhanced by processes within the canopy. Mercury entering the forest floor, largely via throughfall and litterfall, may be a factor of two or more greater than wet deposition. Following deposition, mercury undergoes a series of complex pathways and transformations, which interconnect with other element cycles and ultimately control the supply of methyl mercury to aquatic biota.The specific objectives of this study of Biocomplexity in the Environment are to quantify the inputs, transformations and losses of mercury species in an upland northern hardwood forest; determine conditions controlling the complexation, immobilization and net methylation of mercury; and assess the fate, transport and bioavailability of atmospheric mercury deposition across the Adirondack landscape.In terms of broader impacts, this project addresses the cycling of mercury in the environment, an element identified as being of risk to human health in certain concentrations and under certain environmental conditions. The research will provide a unique learning experience for undergraduate and graduate students supported by the research. Also, the investigators envision a wide ranging educational public outreach effort that takes advantage of a successful program being run in conjunction with the Adirondack Ecological Center and the Adirondack Museum.