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OUTDOORS: Species-rich Coosawattee a state eco-treasure

The goldline darter is just one of several rare species found in Georgia’s unique Coosawattee River system. (Bob Kornegay/Special to The Herald)

The goldline darter is just one of several rare species found in Georgia’s unique Coosawattee River system. (Bob Kornegay/Special to The Herald)

The Coosawattee River system is one of the richest waterway networks in Georgia. Teeming with diverse and rare species, the river system is a prime example of unique and vital wildlife habitat, unique even in a state where unique and vital habitat is comparatively abundant.

Scientists have long known there was “gold” to be found in the Coosawattee. This ancient river system coursing through the north Georgia Appalachian foothills is one of two places on Earth where rare goldline darters are found. However, Georgia Department of Natural Resources surveys in the Coosawattee and its tributaries have mined a wealth of aquatic creatures that reaches beyond the federally listed goldline darters. Those finds include three more protected darter species, plus species of mussels documented for the first time above Carters Lake.

Dr. Brett Albanese, senior aquatic zoologist with DNR’s Nongame Conservation Section, said the discoveries not only expand the range of these rare species, they spur hope that “having more of them present in the basin will help increase conservation efforts” in the Coosawattee River system overall.

With the Ellijay and Cartecay rivers merging to form the Coosawattee in Ellijay, the system drains southwest to Carters Lake and continues below the dam to join the Conasauga River near New Echota, the former Cherokee Nation capital. One Coosawattee claim to fame is that it helped inspire the bestseller “Deliverance.” Another claim: The aforementioned goldline darters, slim, small fish dabbed with gold on the sides and classed as threatened under the U.S. Endangered Species Act. Goldline darters exist only in the Coosawattee and in Alabama’s Cahaba River system.

As part of a project to assess the darters’ status, the Nongame Conservation Section began surveying the Coosawattee in 2009. That work documented a stable darter population upstream of Carters Lake, but rated the species as possibly extirpated (no longer existing) in the lower Coosawattee and Talking Rock Creek, a major Coosawattee tributary.

Those data are obviously vital for conserving goldlines, but surveys provided more, thanks to partners including The Nature Conservancy, Georgia Museum of Natural History and the Coosawattee Watershed Alliance. Cooperative goldline darter research led to other interesting finds as well.

Although researchers didn’t capture any goldline darters downstream of Carters Lake, they did net three other rare darter species: the federally endangered amber darter and state-endangered freckled and trispot darters. This represents the first documented occurrences of amber and freckled darters in the Coosawattee system and a considerable increase in the global range of the amber darter.

Also, when a survey crew searching for state-listed holiday darters spotted mussel shells in the Ellijay River and Boardtown Creek, biologists followed up in 2013 and quickly found populations of two mussel species never collected upstream of Carters Lake. These bivalve mollusks are the federally threatened finelined pocketbook and the state-endangered Alabama creekmussel. The scientists also found the Etowah heelsplitter, a mussel species of special concern also not documented upstream of the reservoir.

Georgia DNR mussel specialist Jason Wisniewski said what interests him even more is the size of the mussels. They’re small. And for these long-lived creatures, smaller means younger. The presence of younger individuals is encouraging.

What researchers saw, Wisniewski said, is evidence of a reproducing population of mussels. “The reproduction factor is what is really important.”

Rare, bladder-less fishes and shellfish aren’t the only unique creatures inhabiting the Coosawattee system.

In 2009, three eastern hellbenders were caught in the Cartecay River, the first occurrence of this mega-salamander in the Mobile River basin, which includes the Coosawattee system. A genetic study suggests ties to hellbenders in the Toccoa River. What is not known is whether the Cartecay hellbenders dispersed naturally from the Toccoa system or whether people introduced them to the Cartecay.

Joined by Georgia College professor Dr. Chris Skelton, surveyors also found Coosawattee and beautiful crayfish, two freshwater crustacean species that, like eastern hellbenders, are petitioned for federal listing.

According to Albanese, one of the biggest “discoveries” regarding the Coosawattee is the heightened need for further research.

“All of these discoveries lead to more information needs,” he said, “and more emphasis on conserving the river system anchored by the Coosawattee. This system is home to more than 70 native fishes and ongoing threats to it include habitat loss, urbanization and agricultural impacts such as runoff. Having sound information on species of concern, including how rare they may or may not be, is critical for managing them and deciding whether or not they warrant federal listing.”

“The key,” added Wisniewski, “is doing what’s necessary from the conservation standpoint to try and preserve those species populations and document as many as you can so you know where they are.”

Along the Coosawattee, that is an ongoing effort. Hopefully, another story of “deliverance” is being written.