Article for January - February 2010
After an oyster roast, don't throw away those shells. Donating them to the S.C. Department of Natural Resources’ Oyster Shell Recycling program can help improve South Carolina’s oyster population.
The science is simple: Oyster larvae (called spat) attach themselves to existing shells and other hard masses (known as cultch), building new homes on old foundations. The Oyster Shell Recycling program tries to provide plenty of places for these larvae to land. The program crew collects shells from restaurants, caterers, festivals and backyard oyster roasts. Then, during the critical summer months when oysters spawn, the crew deposits those shells on state and public oyster grounds up and down the coast.
During the 2009 spawning season, the program recycled 16,161 bushels of oyster shells and returned 18,762 bushels to South Carolina waters, providing homes for countless new oysters.
Many oyster shells are donated to the program by individuals and civic groups that hold oyster roasts, explains program manager Andy Jennings. "They'll call us; we'll pull a trailer over there and maybe pick it up the next day."
The program also maintains oyster shell drop-off sites. "We have twenty-two set up in the coastal counties," says Jennings. "We're working on getting some more sites set up this year." Unfortunately, all the drop-off sites are in coastal counties. In the Midlands and Upstate, lots of shells end up paving driveways or, worse, in landfills. "That's a major problem," says Jennings. "I'd love to be able to catch all those shells from up there."
The collected shells are hauled to one of four big repositories, where they are quarantined for six to twelve months. Left to dry in the sun, the shells are rid of diseases and hitchhiking species that may be on the oysters imported from other states that could harm South Carolina's oysters. The recycling program staff also clean the shells, carefully picking through them to make sure no trash remains.
When the shells are ready to be reintroduced to the water, the crew uses a dump truck and front-end loader to transport the shells to a boat ramp. A small tractor pushes them into a machine called a force feed loader that quickly moves the shells up onto a barge. Oyster shells aren't light—each barge load is 1,000 to 1,200 bushels of shells, weighing 60,000 pounds or more. At high tide, the barge makes its way to the oyster grounds, where the crew uses a high pressure water cannon to blast the shells off the barge and into the water at the selected site.
Jennings says state biologists' annual surveys of shellfish grounds show the program is working. And though oyster populations have been in decline worldwide for some time, says Jennings, the South Carolina population is less threatened. "We had a record commercial oyster harvest last year," he says. "Best we've had in fourteen years."
For more information about the DNR's Oyster Recycling and Restoration program, including shell recycling drop-off locations and ways for citizen volunteers to get involved with oyster-bed restoration, visit www.dnr.sc.gov/marine.html. (Click on the "Shellfish" link on the left side of the page.)
© 2010 South Carolina Wildlife Magazine, January - February 2010 - www.scwildlife.com