Twentieth century changes in the freshwater mussel fauna of the Clinch River (Tennessee and Virginia)

This study investigated the current status of freshwater mussel populations in the Clinch River since first being reported by Ortmann (1918). Freshwater mussel species have declined from a reported 60 species to the 47 species identified in this study. Impoundments have drastically reduced the mussel fauna in the lower Clinch and mussels have failed to recolonize a portion of the upper Clinch below Carbo, Virginia, following two major toxic spills in 1967 and 1970.

There was a distinct longitudinal distribution of mussel species in the upper Clinch with an increase in the number of species downstream with increasing stream size. Abrupt changes in stream gradient were effective physical barriers for mussel distributions in the upper Clinch.