ANCIENT FISH IN PART DETERMINES HARTWELL LAKE LEVELS
By Vince Jackson
A boney fish that has been around for more than 200 million years has a lot to say about water levels in Hartwell Lake, according to the US Army Corps of Engineers.
The short-nosed sturgeon, a brownish fish that can grow to four feet in length, inhabits the Savannah River Basin and is one reason, cited by the Corps, for the need to provide mandated downstream flow from water impounded in lakes Thurmond, Russell and Hartwell.
The sturgeon has been on the federal Endangered Species list since 1973, according to the Department of the Interior. It spawns in the Savannah River from January to late spring when the female lays tens of thousands of eggs on gravel river bottom. The eggs need moving water to be viable. Sturgeon experts say that water velocity of 30-120 centimeters per second is needed for proper aeration and hatching of the eggs.
Billy E Birdwell, chief of public affairs for the Corps Savannah District, says that provisions of the Endangered Species Act require that the Corps maintain flow rates that will sustain the ancient fish. The Corps is currently maintaining a flow rate of 3100 cubic feet per second for the Savannah River Basin. During the past week releases from Hartwell Dam have stopped, but could resume at any time, says the Corps.
“The short-nosed sturgeon’s spawning season may require us to resume 3600 cfs outflows from the Thurmond Dam in February. It is the only one (endangered species) to impact the reduced outflows this winter. There may be other species (i.e. pearly mussel) impacted at other times of the year, but since the states (GA and SC) only requested reductions in the winter, those species do not impact our current outflow reduction,” said Birdwell.
“Our concern centers on our dedication to protecting endangered species– especially those living in the waters of the US and our wetlands,” Birdwell said.
Also known as the little sturgeon, the short-nosed is one of the smallest fish in a family that has as many as 20 members, say researchers. Their life cycle involves migrating up and down river systems and spending time at sea or in the brackish estuaries along the coast around Charleston.
William Graf, a professor of water resource management at the University of South Carolina, says that obstacles to the sturgeon’s migration, such as dams, prevent it from completing its migration cycle. Graf writes that he believes that the population of sturgeons collapsed in many east coast river systems after dams were built for flood control.
Steven Hernandez-Divers, University of Georgia veterinarian, has conducted research on the fish and has written that it is highly threatened and vulnerable to extinction. Males can live for up to 30 years and females as old as 67 years have been documented, he says.
Sturgeons are bottom feeders dependent upon insects, crustaceans and mollusks for food. They were commercially fished from about 1800 to 1900 for meat and caviar (fish eggs), but all fisheries have been closed to the short-nosed sturgeon since 2002, according to the U S Marine Fisheries Service.