Taking an educated guess about the likely cause of the problem, the fishery professionals surmise that somebody dumped a live-well full of Alabama spotted bass, possibly from near-neighbor Lake Lanier in Georgia, into Lake Keowee, and South Carolina’s special redeye bass, found only in the Savannah drainage, hailed them as long-lost cousins and crossbred with them. The indeterminate fish are the hybrid fallout from this crossbreeding. The fishery professionals, just beginning a study to explore the extent of the intermixing, feel justified in their concern that as a result of the Alabama spotted bass’s unwelcome invasion, the Savannah’s genetically unique redeye is at risk.

    Subsequent to this March 2004 day on the lake, says DNR fisheries biologist Jean Leitner, DNR specialist went on to collect a total of more than 1,300 fish from lake Keowee, Jocassee, Hartwell and Russell and from 11 stream sites, all within the Savannah watershed. Leitner reports, “After our collaborators at the University of South Carolina performed DNA analysis on the fish collected, they confirmed that hybrids between the introduced Alabama spotted bass and native redeye bass are present in lakes Jocassee, Keowee, Hartwell and Russell—to the greatest extent in lakes Keowee and Russell. Spotted bass and hybrids sampled to date from these two lakes outnumber redeye bass.”

    Sure of their ground now, biologists have continued their study, conducted in collaboration with colleagues at Duke Energy and Dr. Joseph M. Quattro of the University of South Carolina’s Biological Sciences Department, director of the ongoing genetics work. Some good news has come out of their united efforts: With two exceptions, the streams that feed into the lakes and the Savannah River were clear of hybridization so far, and on lakes Jocassee and Hartwell pure redeye bass still outnumber hybrids.