Methylmercury Uptake by Freshwater Phytoplankton: Analytical and Modeling Methods

In this talk (Slide 1), I will summarize the studies of methylmercury uptake by freshwater phytoplankton that Carl Watras and I have been conducting over the past few years. These investigations have helped motivate the development both of new analytical methods by Dr. Watras and his mercury biogeochemistry group located at Trout Lake Station in northern Wisconsin and new modeling approaches by myself in collaboration with Carl and Steve Gherini of Tetra Tech, Inc. A major goal of our studies has been to identify and model the mechanism of methylmercury uptake by phytoplankton (Slide 1). This process is important because most of the mercury in fish is accumulated by transfer through aquatic food webs after first being absorbed from the water at the lowest trophic levels. Lake water quality appears to have a strong influence on this step. Thus, our efforts are directed towards enabling us to better predict the levels of mercury in aquatic organisms from diverse aquatic systems and provide a sound scientific basis for resource management and regulatory decisions.