SCDNR - News Release
January 31, 2005
DNR Stocks over two million Red Drum in coastal waters
During the fall of 2004, the S.C. Department of Natural Resources stocked red drum into South Carolina's estuaries in Charleston, Beaufort and Georgetown counties.
S.C. Department of Natural Resources (DNR) biologists released over 2.4 million juvenile red drum into four estuaries: 140,000 fish in Broad Creek in Beaufort County, 680,000 fish in the North Edisto River in Charleston County, and a total of 1.6 million fish into Murrells Inlet and Winyah Bay estuaries in Georgetown County.
Red drum are also known as spottail bass and redfish, and are considered to be the state's most popular inshore fish sought after by anglers.
"This is the most fish we have ever released in one year, and it is due to the extraordinary dedication of the staff involved in the production, marking and release of the fish," said DNR biologist Wallace Jenkins.
The DNR's stocking efforts in 2004 were expanded to include Winyah Bay, which received nearly one million fish because of its size. The U.S. Fish and Wildlife Service's Bears Bluff National Fish Hatchery on Wadmalaw Island produced 535,000 of the fish that were released in the North Edisto River.
The goal of the stocking project is to supplement management regulations and help increase the population of red drum along South Carolina's coast. The Atlantic States Marine Fisheries Commission currently defines the red drum fishery as "over-fished." The changes in size and catch limits that were enacted by the South Carolina General Assembly in August of 2001 are projected to help the population recover and become "sustainable" in the future. The next population assessment when completed in 2007 will show progress towards this goal.
Each year the DNR collects adult red drum from the wild. Those fish are encouraged to reproduce, or spawn, to produce the fish that are stocked in the estuaries. "The approach mimics the fish's natural cycle by having the red drum spawn during their regular mating season of August and September," Jenkins said.
Once the adult red drum spawn in the DNR lab at Charleston, biologists move the larvae to rearing ponds at the DNR's Waddell Mariculture Center in Bluffton. When the offspring reach about one inch in size they are harvested and released into their natural marsh habitat at sizes similar to that of wild juveniles.
"The primary difference and advantage is that the stocked fish are protected from predators for their first month of life compared with their wild counterparts, which enter the estuary near the bottom of the food chain and are more vulnerable to predation and environmental influences," Jenkins said.
Before being released, the fish are "marked" by exposing them to a chemical called oxytetracycline. The chemical binds to their bones and can be seen when biologists look at a thin slice of an ear bone, called an otolith, under a special microscope. In addition, genetic identification techniques developed by DNR researchers working at the Hollings Marine Lab have resulted in all fish being naturally marked in the hatchery. This technique allows stocked fish to be identified after being released into the wild by simply clipping a portion of the fin and performing the genetic analysis.
Marking of the fish is an important part of the stocking process. It allows DNR biologists to evaluate the success of each year's stocking efforts. After a minimum of one year after stocking a particular area, biologists estimate how many fish in a particular area are stocked versus wild. It is the marking process that enables the biologists to distinguish between stocked and wild fish so they can determine their success.
Even with the new fin clipping technology, the DNR still asks for assistance from the public to obtain any heads, known as "racks," from red drum legally taken by fishermen. The public can take the racks to freezers located near the stocked areas. Biologists use the ear bones and tissue samples from these donated fish to help assess the success of the stocking project.
Because of the law change in 2001 that made the legal minimum size for red drum more conservative, obtaining racks from each year class has been somewhat delayed. "We are just starting to get enough racks to determine the contribution of fish that were stocked in 2002," Jenkins said. "At present it appears that stocked fish make up 5.3 percent and 6.3 percent of the 2002 year class in Murrells Inlet and the May River, respectively."
On one occasion, a red drum that was stocked in Murrells Inlet in 2002 was recaptured by a fisherman near Pawley's Island in the fall of 2004. This fish was recaptured in November of 2004, and had grown from a stocking size of less than two inches to a total length of 23 inches. In the fall of 2002, 553,088 red drum were stocked in Murrell's Inlet. Fishermen in Murrell's Inlet have turned in 213 fish that were from the 2002 year class. So far, 11 of those 213 have been identified as fish that were stocked by the DNR. In addition to those 11 recaptures, one fish that was turned in from the 2003 year class has also been identified as a stocked fish.
Revenues from the South Carolina Saltwater Recreational Fishing License Program support this project's goal to increase the abundance of the state's most popular saltwater game fish. "The fishermen themselves play an key role in both funding and data collection for the red drum restocking program," Jenkins said. Funds from the S. C. Sea Grant Consortium and the US Fish and Wildlife Service Sport Fish Restoration Act also support the program.
For more information on the program or locations of freezers contact Wallace Jenkins at 843-953-9835 or via email at firstname.lastname@example.org. To view photos and videos of the stocking project, visit the DNR's Saltwater Recreational Fishing License Web site at http://saltwaterfishing.sc.gov, and click on "Red Drum Stock Enhancement" on the left-hand column.
- Written by Jennie R. Davis -