THE FRESHWATER MUSSEL AS A BIOLOGICAL MONITOR OF PESTICIDE CONCENTRATIONS IN A LOTIC ENVIRONMENT1

Abstract

Two species of freshwater mussels were introduced into the Red Cedar River at six different locations and analyzed for pesticide content following different lengths of time in the river. DDT and its metabolites, TDE and DDE, were found in all mussels analyzed. The concentration of DDT and its metabolites increased significantly in a downstream direction and increased significantly with time before reaching a plateau. Methoxychlor was found in mussels introduced into the lower sections of the study area. Aldrin was found in all mussels on two dates of retrieval from the river but was not found before or after these dates. Mussels collected from the upper portion of the study area contained small concentrations of DDT and its metabolites. There was no significant difference in pesticide content between species.