Dakin, E.E., B.A. Porter, B.J. Freeman, and J.M. Long. 2007. Genetic integrity of an isolated population of shoal bass (Micropterus cataractae) in the upper Chattahoochee River basin. National Park Service, Natural Resources Report NPS/NRWRD/NRTR—2007/366, Ft. Collins, CO.
Abstract
Four populations of shoal bass (Micropterus cataractae) from the Chattahoochee River basin in Georgia were genotyped at ten highly polymorphic microsatellite loci in order to compare the genetic variation and divergence between populations. The shoal bass population in Big Creek (a tributary of the Chattahoochee River which enters just upstream of the Morgan Falls Dam) has reduced genetic diversity compared to two downstream populations, and is highly differentiated (average Gst=0.1556) from a population found just below Morgan Falls Dam. Overall, genetic diversity increases downstream in the Chattahoochee River from a population above Lake Sidney Lanier (the reservoir above Buford Dam) to Big Creek to the population just below Morgan Falls Dam, indicating that the two dams probably severely limit downstream dispersal by shoal bass, and eliminate upstream migration altogether. The shoal bass in Big Creek are limited to a very short stretch of appropriate habitat, show limited genetic diversity and high differentiation from other populations, and thus could be in danger of suffering from the effects of genetic drift and inbreeding.