The discovery of a federally endangered amber darter in North Georgia’s Coosawattee River raises hope for the survival of a rare fish known from only two other river systems.
Recent sampling on the Coosawattee below Carters Lake actually produced three surprises: the amber darter and two state-endangered freckled darters. Neither species had been documented in the river before.
The finds reveal the biological diversity of a seldom-sampled waterway, and resource agencies hope they may factor into the management of improved flows from Carters Lake dam.
Brett Albanese, a senior aquatic zoologist with the Georgia Department of Natural Resources, called the catches “amazing.” The amber darter and a freckled darter were netted July 29; the second freckled darter was caught early this month. Both species had been found only in the nearby Conasauga and Etowah river systems, part of the Coosa River basin of northern Georgia, southern Tennessee and eastern Alabama.
Albanese said scientists need to learn more about the status of amber darters in the Coosawattee, where deep water and swift currents make sampling difficult. Noting that the Etowah population is isolated upstream of Lake Allatoona, he said, “We don’t know if this single fish represents a long-distance dispersal from the Conasauga population or if it is an indicator of a local population. In either case, having a third river where this species can survive decreases its overall risk of extinction.”
More is better for the slender, 2 ½-inch-long fish that makes its home in riffles. Annual monitoring has shown a stable population of amber darters in the Etowah, but a small and possibly declining population in the Conasauga.
The recent surveys are part of a yearlong inventory of shallow-water habitats and the small fishes that use them in the Coosawattee and Etowah below lakes Carters and Allatoona, respectively. The University of Georgia, the U.S. Fish and Wildlife Service, the U.S. Geological Survey, The Nature Conservancy and the DNR are doing the work downstream of the Army Corps of Engineers reservoirs.
A deeper understanding of what is in each river reach fits U.S. Fish and Wildlife Service and Georgia State Wildlife Action Plan priorities. Data can also help guide the federal wildlife agency’s input into an ongoing, basin-wide update of corps water control plans for Carters and Allatoona.
Possible genetic links between amber darters in the Coosawattee and in the Etowah and Conasauga will be probed. Overall, the presence of these small but special fishes raises more questions about the Coosawattee, Albanese said.
“There are other species found in the Conasauga and Etowah rivers that may also occur in the Coosawattee, and we are excited to go look for them.”
- After surveys in the upper Coosawattee, the river was recognized as one of Georgia’s top three rivers for imperiled fishes in 2009. Read more at www.georgiawildlife.com/node/1827.
- The federally threatened goldline darter is found in Georgia only in the Coosawattee.