You are here

Water Quality

Blotched ChubThe dense network of rivers and mountain streams in Western North Carolina supports highly diverse aquatic ecosystems, including many species of fish, mussel, snail, crayfish, amphibian, and reptile. The increasing threat to aquatic communities in the region is primarily due to habitat degradation and destruction, point and nonpoint source pollution, dams and impoundments, and the introduction of non-native species. Fish commonly found in the region include native brook and non-native brown and rainbow trout, bass, crappie, many species of perch, catfish, minnow, darter, and sucker.

Appalachian Elktoe Mussel

Native brook trout, which once thrived in cold mountain streams across the region, have been severely impacted and are now found in less than 80 percent of their historic range. Noonday Globe SnailThe majority of populations are currently found in the Nantahala and Pisgah National Forests and the Great Smoky Mountains National Park. Sensitive to changes in stream chemistry, stream temperature, competition from other trout species, and land use change, native brook trout continue to need protection and restoration.

Freshwater mussels, found in the shallows of streams and rivers, require cool, clean, well-oxygenated water with riffles, runs, and shallow flowing pools with stable, silt-free, rocky stream beds. Stream bed stability is critical to mussel survival, and they are seldom found in areas with accumulations of silt or shifting sand. Smoky DaceFreshwater mussels, especially in their early life stages, are extremely sensitive to chemicals found in wastewater, such as chlorine, ammonia, heavy metals, or high concentrations of nutrients. The destruction of river habitats by dams, channelization, erosion, and pollution has left several species of mussel on the brink of extinction.

Crayfish are freshwater crustaceans found in streams, rivers, swamps, ponds, and other aquatic habitats with flowing water and cover. The small range of many crayfish species is a primary factor in their vulnerability to habitat loss and competition. Threats to crayfish include pollution, impoundment, and competition with non-native species.

Little-Wing Pearly MusselThe southern Appalachian region is the world’s center for salamander diversity. According to the Southern Appalachian Biodiversity Institute, nearly 10 percent of global salamander diversity and 10 percent of freshwater mussel diversity occur here. Salamanders are inhabitants of springs, seepages, and streams. They live in bottomland as well as high elevation forests throughout the region. Species diversity is high because many species are at the southern limit of their distribution and gradients in elevation, aspect, slope, and rainfall contribute to a range of available niches and habitats.

Snails play a dominant role in the ecology of the region’s freshwaters by providing food for many other animals and by grazing on vast amounts of algae and debris. Wounded DarterThey are critical to normal ecological processes in rivers and as indicators of water quality. Freshwater snails are in decline, especially those that inhabit streams and rivers. Dam construction and other channel modifications, siltation, and industrial and agricultural pollution have degraded the river habitats on which most species depend.

The continued loss and decline of freshwater snails, mussels, fish, crayfish, amphibians, and reptiles demonstrates that, Pygmy Salamanderdespite significant water quality improvements made in the last 28 years since the passage of the Clean Water Act, species loss is still a critical concern in the region.

The U.S. Fish and Wildlife Service currently lists 11 fish, 7 mussels, 2 crayfish, 4 salamanders, and 5 snails as federally threatened, endangered, or species of concern in river basins across the region.Many of these are found in the Hiwassee, Little Tennessee, and French Broad basins. Additionally, the State of North Carolina has identified at least 50 additional aquatic species of priority concern in the nine river basins in Western North Carolina.

Federally Listed Threatened Species, Endangered Species, and Species of Concern in Western North Carolina, 2010





Blotchside logperchCarolina heelsplitterFragile glyphPygmy
Kanawha minnowTennessee clubshellClingman covertSeepage
Olive darterTawny crescentNoonday globeHellbender
Sharphead darterGreen floaterRoan supercoil (land)Junaluska
Sickle darterAppalachian elktoeSculpted supercoil (land) 
Wounded darterCumberland bean  
Smoky daceLittle-wing pearly  
Sicklefin redhorse   
Blotched chub   
Spotfin chub   


USDA Forest Service, National Forests in North Carolina. “Federally listed aquatic threatened, endangered, and species of concern.” G. Kauffman, personal communication, 2010.

Crandall, K.A., and J.W. Fetzner. “Crayfish conservation.” Accessed from:, updated 2006.

NC Wildlife Resources Commission, “Wildlife Species and Conservation, North Carolina Freshwater Mussels.” Accessed from:, 2010.

Willson, J., Y. Kirnilev, W. Anderson, G. Connette, and E. Eskew. “Salamanders of North Carolina.” Accessed from:

Photo Credits:

Blotched Chub: Brett Albanese, Georgia Department of Natural Resources.

Appalachian Elktoe Mussel, Little-Wing Pearly Mussel, Noonday Globe Snail: Dick Biggins, U.S. Fish and Wildlife Service.

Pygmy Salamander: Matthew Niemiller. Accessed from:

Smoky Dace, Betty Creek: Katie Owers.

Wounded Darter: Bud Freeman, Georgia Museum of Natural History, 2008.