Clearing the Water for Mussels

science needed to improve water quality for restoring freshwater mussels—our Nation’s largest group of threatened and endangered animals. There is wide agreement that North America’s native freshwater mussels are in decline (Master et al. 2000, Lydeard et al. 2004). Of the nearly 300 native species, 35 are considered extinct (Turgeon et al. 1998), and 70 are listed as threatened or endangered in the U.S. under the Endangered Species Act. Although many environmental problems contributed to the decline of freshwater mussels, water pollution is among the leading factors limiting their recovery (Richter et al. 1997, Strayer et al. 2004). Improving water quality will be necessary to restore many imperiled populations, and biologists working to recover mus-sels have looked to toxicologists for help in identifying specific pollutants. The Native Mussel Conservation Committee (1998) has issued explicit calls for deter-mining mussel pollutant sensitivities and determining if water quality criteria and standards are sufficient for recovery