Imperiled Aquatic Species

Imperiled species are those believed to be at some risk of extirpation or extinction; here, threatened, endangered, and special concern species are collectively referred to as imperiled species.  Threatened and endangered (T&E) species have officially been listed by the U.S. Fish and Wildlife Service (FWS) under the Endangered Species Act of 1973. Special concern (SC) species may be limited in distribution and abundance, but the legal listing process has not been completed; these species are recognized by NatureServe as having globally limited distributions (G1, G2, G3). Most of the imperiled species in the southern Appalachian region are in decline due to habitat alteration and loss.

Key findings of the Southern Appalachian Assessment (SAA) Aquatic Report (SAMAB 1996) regarding imperiled species from state Natural Heritage Programs and FWS Threatened and Endangered Species lists are:

• The State Heritage Program lists include 190 aquatic and semiaquatic T&E and SC species in the SAA area; of these, 62 are fish and 57 are molluscs.
• Of the 34 endangered species on the State Heritage Program lists, 26 are molluscs and 7 are fish.
• The 10 counties with the greatest number of aquatic TE&SC species on the State Heritage Program lists are in three areas: the Clinch and Powell river drainages of Virginia and Tennessee; the area around Knoxville and Oak Ridge, Tennessee; and Monroe County, Tennessee. This overall pattern largely reflects patterns for fish and molluscs.
• According to the FWS, 46 threatened and endangered aquatic species are known to occur and 7 others possibly occur in SAA area counties. The nine counties known by FWS to have the greatest number of threatened and endangered aquatic species include the same six counties in the Clinch and Powell river drainages of Virginia and Tennessee that were identified in the heritage program data set as harboring the most T&E and SC species and two counties in Georgia, which are primarily in the Conasauga River drainage.

Imperiled fishes, molluscs, reptiles, amphibians, and invertebrates in the southern Appalachian region include species that are federally protected and those that are globally rare.