Limestone helps restore reefs in Pamlico Sound

HATTERAS, N.C.

Limestone marl, unremarkable concrete like lumps, has been dumped by the tons into Pamlico Sound. And many people are very happy about it.

But the happiest of all may be the oysters, shellfish and finfish that scientists hope will be attracted to the oyster sanctuary reef about five miles off Hatteras, serving as a sort of underwater nursery, aquatic gathering spot and oyster brood stock preserve.

"You're restoring a habitat," said David Eggleston, professor of marine ecology and conservation at North Carolina State University. "It cleans the water. It's culturally important to the area. It helps other fish.

"So you really get a lot of bang for your buck."

Eggleston was a board the Miss Hatteras last week for an Earth Day celebration tour of the Clam Shell reef site, paid for with a $5 million federal economic stimulus grant to the National Oceanic and Atmospheric Administration.

NOAA, in turn, gave the grant to the North Carolina Coastal Federation. Other partners in building and monitoring a total of 47 acres of oyster reefs in Pamlico Sound include North Carolina Sea Grant, the state Division of Marine Fisheries, North Carolina State University and the University of North Carolina-Wilmington.

The project has allowed Stevens Towing Co. North Carolina to rehire workers who had been laid off, said Simon Rich, general manager, explaining the work going on off a barge on the water. The limestone rock, or marl, has been transported from a quarry near New Bern to a loading site in Belhaven, he said, requiring the operation of trucks, tug boats, barges and heavy equipment.

Cone-shaped mounds of the rock, about 7 feet below the surface, were placed in a checkerboard pattern. The work is expected to be completed in May, and it won't be long after that anglers will be welcomed at the reef.

"You can anchor on it, fish on it," he said. But oyster harvesting, of course, will be prohibited.

Work began off Hatteras in January, soon after another sanctuary reef was completed off Stumpy Point at Crab Hole. Other mounds that were built off Ocracoke in 2005 are now covered in oysters and are considered successful.

Restoration of the oyster reefs in coastal North Carolina is part of a strategic plan to revitalize the historic fishery. Maps from the 1880s show Pamlico Sound filled with oyster reefs, with more than 20,000 acres estimated to be covering the bottom. Scientists believe development may have been a contributing factor in the reefs' demise.

"This site was selected because it's very good recruitment for oyster larvae," said Craig Hardy, chief of the resource enhancement section of the state Division of Marine Fisheries.

Oysters spawn in the spring, he said, and they look for clean, hard material to settle on. The strong ones will survive and drift off on currents to other reefs. If left alone and unharvested, Hardy said, ideally the oysters will repopulate themselves.

Considering that one oyster can filter up to 50 gallons of water a day, removing particulate matter and leaving the water clearer, more oysters could be good news for Pamlico Sound. And clearer water, Hardy said, means healthier submerged aquatic vegetation, which will foster healthier fish nurseries and habitat.

Eggleston said the partners next want to build other oyster sanctuaries along the western shore of the Pamlico Sound.

"I'm really encouraged," Eggleston said. "We've seen oyster densities increase 400 percent since 2006. Every sign that you can imagine shows that it's positive. All lights are green that we should keep doing what we're doing."

Catherine Kozak, (252) 441-1711, cate.kozak@pilotonline.com