SS4.03 Factors Controlling the Bioavailability and Bioaccumulation of Inorganic and Organic Chemicals into Aquatic Food Chains
Date: Thursday, June 13, 2002
Location: Poster Session - VCC
 
Peterson, M, J, Oak Ridge National Laboratory, Oak Ridge, TN, USA, petersonmj@ornl.gov
Southworth, G, R, Oak Ridge National Laboratory, Oak Ridge, TN, USA, southworthgr@ornl.gov
HouserJN, Oak Ridge National Laboratory, Oak Ridge, TN, USA, houserjn@ornl.gov
 
EFFECTS OF LOCAL ENVIRONMENTAL FACTORS ON MERCURY BIOACCUMULATION IN EAST TENNESSEE
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The conversion of inorganic mercury to methylmercury, and the subsequent accumulation of methylmercury by aquatic biota, is a complicated process affected by a large number of physical, chemical, and ecological factors. Since the early 1980s we have conducted monitoring investigations and empirical studies to help define the role of these various factors in mercury bioaccumulation, particularly in industrial settings. Remedial actions targeting various pollutant sources have provided opportunities to observe responses in mercury bioaccumulation to changes in ecological factors as well as mercury inputs. In several cases, mercury levels in biota have responded counter-intuitively. For example, reduction of inputs of dissolved inorganic mercury to a contaminated pond did not result in a striking decrease in waterborne methylmercury concentrations, but did produce a rapid decline in mercury concentrations in fish. In another case, a long term decrease in inorganic mercury loading to a contaminated stream produced little change in mercury bioaccumulation. Altogether, these localized studies in east Tennessee highlight the complexity and site-specific nature of mercury bioaccumulation.