Acute toxicity of several pesticides, organic compounds, and a wastewater effluent to the freshwater mussel, Anodonta imbecillis, Ceriodaphnia dubia, and Pimephales promelas

This laboratory study examined the toxicity of a suite of chemicals and organic compounds on juveniles of the freshwater mussel Anodonta imbecillis. Depending on the substance tested, A. imbecillis sensitivity was compared to that of the zooplankton Daphnia magna, the zooplankton Ceriodaphnia dubia, or the fathead minnow Pimephales promelas, which are organisms commonly used in toxicity studies.

In order of highest to lowest toxicity to A. imbecillis, the tested substances ranked PCP (pesticide and disinfectant), toxaphene (insecticide), chlordane (pesticide), EDTA (industrial and medical use), hydrothal (herbicide), SDS (surfactant), acetone (solvent), and methanol (alcohol chemical). Overall, A. imbecillis was not highly sensitive to most of the tested substances. In fact, A. imbecillis was less sensitive to all tested substances than D. magna, except for PCP which was acutely toxic to A. imbecillis juveniles. Sensitivity to 48-hour and 7 day treatments of wastewater effluent was also tested; A. imbecillis was less sensitive than C. dubia or P. promelas. The authors concluded that further testing would be necessary to determine the long-term effects of these and other substances on freshwater mussels.