Longtime resident of South Carolina's waterways, the endangered shortnose sturgeon dates back to pre-Jurassic times. It is one of eight sturgeon species identified in North America, two of which inhabit South Carolina.
   Today, these aquatic antiques, highly valued for their eggs, consumed as caviar, are threatened by loss of habitat caused by dam construction, overfishing and pollution. A S. C. Department of Natural Resources (DNR) study now under way will determine the extent of the threat to these valuable and fascinating fish.
   Sturgeons are anadromous, meaning they spend most of their life in saltwater but swim up freshwater rivers and streams to spawn.
   Because sturgeons have a slow growth rate and do not reproduce until they are at least seven years old, it is difficult for sturgeon populations to recover from harvesting, and dams prohibit access to spawning areas.
   The DNR Wildlife and Freshwater Fisheries Division is working to determine whether dams have a negative impact on shortnose sturgeon populations in South Carolina and to devise ways to mitigate that impact.
   Using a variety of techniques, including a 3-D tracking system, primitive egg collectors and standard gill nets, DNR biologist Doug Cooke is monitoring sturgeon activity specifically in the Santee-Cooper river system.
   This research, funded as part of the Federal Energy Regulatory Commission relicensing by Santee Cooper, monitors sturgeon activity to determine how turbine discharge patterns affect spawning below the dam, how Santee Cooper may enhance sturgeon passage through the navigation lock, and what will happen to the fish if they do enter the lake system.
   Building upon research conducted more than 10 years ago by the U.S. Army Corps of Engineers-Charleston, the studies underway today began last year and are expected to continue at least two more years.
   Preliminary research indicates about 200 shortnose sturgeons come up the Cooper River each year and spawn below the Pinopolis Dam in Moncks Corner, one of the most downstream spawning sites documented for sturgeon.
Since this is not a typical spawning site, juveniles produced may not have access to the right food resources and nutrients, or may be exposed to more predators, and as a result they might not grow up to contribute to the overall sturgeon population.
   A state-of-the-art 3-D tracking system in place at the lock and dam has traced movements of the fish through the river and around the dam. It is being used to see why many enter the lock but never make it into the lake on the other side.
   Cooke believes this is because of the 50-foot ledge of water created when the lock closes and fills to lake level. These bottom-dwelling fish haven't been able to find their way to the surface, where a door allows passage into the lake.
   "This year we'll be doing tests to determine whether a flow of water might lead sturgeons through the lock," Cooke says. "When the lock is full and the doors open into the lake side, if we create a flow through the lock, will they follow it upstream? Also, we will be tracking fish to see where they go in the lake system.
   "We are working closely with Santee Cooper and the Corps to make a difference to future populations of these species," Cooke says.
 

- Written by Beth Pleming -