Aw Shucks? State Recycles Oyster Shells to Boost Births

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North Carolina restaurants can now toss oyster shells into the recycling bin rather than the trash can.

Following a three-year pilot project, the state is funding a long-term effort to create new reefs from recycled oyster shells.

Lawmakers hope the initiative will regenerate North Carolina’s coastal oyster population and, in turn, stabilize the state’s fishery. The state has classified oyster reefs as “essential marine habitat.”

“We will be collecting shells from restaurants and shucking houses, taking them to sea, and placing them in areas the pilot project research shows reefs can thrive,” says project leader Craig Hardy, of the North Carolina Division of Marine Fisheries.

Benchmark Species

Eastern oyster (Crassostrea virginicus) larvae can swim up to a hundred miles (160 kilometers) before they hunker down to grow into adults. While larvae can settle around docks or boat hulls, their preferred habitat is an oyster shell on an oyster reef.

A hundred years ago, the region’s oyster beds were so large that ships plying the East Coast of the United States from Georgia to Maryland had to navigate around them.

But pollutants and overfishing have reduced the harvest by 97 percent over the last century.

Marine biologists view the mollusk as a benchmark species. Its health reflects the overall aquatic health of both coastal waters and the habitat of up to 300 other marine species, including shrimp, speckled sea trout, and rockfish.

Oysters also serve as natural water filters, making seas cleaner for other ocean species.

An individual oyster filters up to 50 gallons (190 liters) of water daily, transforming pollutants into harmless sediment on the ocean floor.

“They significantly reduce particulates from the water,” said Troy Alphin, a marine biologist at the University of North Carolina at Wilmington.

“Oysters sequester pollutants in their bodies, or they bind them up with other materials and eject them so that they settle in the surrounding sediments. Doing that cleanses the water, allowing other species to thrive.”

North Carolina is building drop-off sites where people can deposit shells. The plan mirrors programs in Maryland, Virginia, South Carolina, Georgia, Florida, Canada’s maritime provinces, and France.

The state has also launched an advertising campaign to discourage restaurant owners from sending shells to local landfills and to encourage diners to ask restaurant owners what they do with their shells.

Alphin and Hardy believe North Carolinians will take to the oyster shell recycling effort.

“Twenty years ago, you didn’t think anything of throwing an aluminum can in the trash,” Hardy said. “Nowadays if you walk by a recycling container and throw that can in the trash, people ask, ‘Why are you doing that?’ It’s just as easy to recycle as it is to throw it away.”

Meanwhile, legislators in both North and South Carolina are considering laws that would ban the dumping of oyster shells in landfills and offer tax credits to people and businesses that donate shells for recycling.

Private Recycling

Bonnie Swartzenberg and her husband Jim grow oysters in a tract of water they lease from the state of North Carolina.

“We have recycled shells and built reefs for several years,” Bonnie Swartzenberg said. “But a concerted effort by the state would make our business more profitable.”

She notes that shell recycling is the best way to breed oysters, because it is virtually impossible to buy oyster larvae on the commercial market.

“The biggest issue we have right now is getting larvae to start our seed,” Swartzenberg said. “You can’t have a crop if you don’t have seed. Building reefs at least gives us some seed.”

“If this program works the way it has in other states, in Canada and in Europe, more larvae will be generated. We hope the reefs become self-sustaining again.”

Jim Swartzenberg says he harbors no illusions that recycling can completely counter the forces that have ravaged North Carolina’s oyster stock.

But he added, “I am excited about what could happen if people who eat oysters, and restaurant owners who sell them returned those same shells to the water.”

For the next several months, the state and private growers such as the Swartzenbergs will build oysters reefs using recycled shells along the North Carolina coast.

Meanwhile, researchers in Georgia and South Carolina say their restoration efforts are already succeeding in creating self-sustaining reefs.

Marine biologists say each time a new reef is created, larvae settle and oysters start growing within hours.

The U.S. National Atmospheric and Oceanic Administration recently launched an investigation to determine if the Eastern oyster should be placed on the federal government’s Endangered Species List.

A decision is expected in January.

Were the Eastern oyster to be classified as endangered, a ban on U.S. harvests would apply to the species, which lives in North American estuaries from Canada’s Gulf of St. Lawrence to Mexico’s Yucatan Peninsula.

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