Graduate Research and Discovery Symposium (GRADS)


Dr. Alan Johnson

Document Type



Agriculture, Forestry and Life Sciences

Publication Date

Spring 2014


The water resources of the Upper Savannah River Basin are subjected to extensive water withdrawals for production of electricity for the region. The use of Savannah River Basin water resources for electricity production and the associated impact on reservoir levels, streamflows, and thermal regimes is in conflict with the requirements of in-stream biota particularly freshwater mussels. The Savannah River Basin contains atleast 26 unionid species, most of which are listed as endangered, threatened, or of special concern at the state level. Populations of these species have experienced significant declines and extirpations in the recent decades. Of these unionid species, brook floater is considered globally vulnerable (G3) and listed as critically imperiled (S1) in 10 states in USA. South Carolina is the only state known to have isolated populations of brook floater susceptible to decline which are not listed in the state’s endangered species list. Habitat loss, hydrologic alterations due to impoundments, changing thermal regimes and lack of connectivity has been identified as the causal factors. The freshwater mussel populations have a potentially limited connectivity in situations where host fish are not available or their movements are restricted by dispersal barriers such as large dams. The research focuses on developing a stage-classified matrix population and metapopulation models. The development of such simulation models will aid in assessing the impact of water use on native freshwater bivalves, with special focus on the brook floater (Alasmidonta varicosa), in the Savannah River Basin and provide assistance in managing water resources for future energy use scenarios.