Methylmercury Production and Fate in Response to Multiple Environmental Factors

Project Leader:
Celia Y. Chen, Ph.D.
Research Professor
Department of Biological Sciences
Dartmouth College

Project Co-Leaders:
Robert Mason, Ph.D.
Professor of Marine Sciences, University of Connecticut
Nicholas S. Fisher, Ph.D.
Distinguished Professor & Director, Consortium for Inter-Disciplinary Environmental Research, Stony Brook University

Our research has focused on mercury in aquatic ecosystems, as consumption of mercury-contaminated fish is a serious public health concern. Mercury takes several forms in the environment: two inorganic forms which are not toxic, and methylmercury, the organic and most toxic form of mercury. Human consumption of fish is the most common source of exposure to methylmercury, which can cause developmental delays in children, motor impairment, cardiovascular effects and other serious health effects.

The current goal of our research project is to investigate the effects of multiple environmental factors associated with climate change on methylmercury production and bioaccumulation in coastal ecosystems. Current climate change models predict increases in temperature, stream flows, and sea level in coastal waters that will impact the thermal conditions, nutrient and carbon loading, and salinity of these marine ecosystems. We are using experimental approaches, field studies, and modeling to examine the combined and interactive effects of temperature, salinity and organic carbon on methylmercury production and fate.

Although elevated inputs of inorganic mercury to ecosystems (from past and present human activities such as coal burning, mining, and industrial processes) are generally thought to result in high concentrations in fish, there are many factors that mediate the ultimate fate and trophic transfer of mercury in the environment. Elevated methylmercury bioaccumulation in fish and fish-eating birds and mammals results from a complex sequence of biotic and abiotic mechanisms that control the transport and availability of inorganic mercury and methylmercury production, bioaccumulation, or biomagnification. Through our research in this project we hope to examine the ways in which our changing climate will impact methylmercury production in ecosystems. This, combined with our past studies in lakes, streams, rivers, and estuaries, will help us better understand the mechanisms that result in elevated methylmercury in the fish that humans consume.

Detailed project history

Publications

Celia Chen All Publications

Robert Mason Pubmed

Nicholas S. Fisher All Publications