Federally Protected Mussel Survey in Elk River

The West Virginia Department of Highways is planning to replace the Camp Creek Truss Bridge (CR 4/5, Clay County) spanning the Elk River near Procious, West Virginia. A previous study in 2001 revealed 17 species of native freshwater mussels located in the direct and indirect impact zone of the existing bridge, including one federally endangered species.

The West Virginia Department of Highways developed four different alternative bridge alignments. Dinkins Biological Consulting was contracted to assess species composition, distribution, and density of the native mussel population within the direct and indirect impact zones of the four alternatives. Both qualitative and quantitative sampling techniques were used to determine which of the four alternatives posed the least threat to the mussel population.

The search for native mussels in the vicinity of each alternative began by conducting a random search in the direct impact zone to identify suitable mussel habitat and general mussel bed boundaries. During this preliminary search, divers fanned out across the search area and recorded species occurrence and general distribution patterns. When a mussel bed was found, it was delineated for subsequent quantitative and qualitative analysis.

A total of 743 live mussels representing 17 species were found in the qualitative and quantitative samples at the proposed four alternative bridge alignment zones. In the vicinity of the existing bridge two mussel beds were identified and two rare mussels, the Pink mucket (Lampsilis abrupta) and the Round hickorynut (Obovaria subrotunda), were found. The Pink mucket is a federally listed endangered species (U.S. Fish and Wildlife Service, 2005), and the Round hickorynut is listed as Species of Concern.