The role of methylmercury production in the transfer of mercury in a salt marsh ecosystem

Abstract

A salt marsh estuary which has received large discharges of inorganic mercury for several years was studied to evaluate the occurrence and production of methylmercury. The methyl form was not detected (<1 ng/g) in marsh sediments or marsh vegetation ( Spartina alterniflora). Significant concentrations were detected in the dominant primary consumers ( Littorina irrorata and Uca sp.). Assuming these organisms accumulated a significant percentage of the methylmercury produced in the salt marsh ecosystem, its annual production there is estimated at about 50 μg/g of total mercury in the upper 5 cm of the sediment column.