OYSTER BAY, N.Y. (AP) – Dave Relyea and a co-worker make sweeping laps up and down a patch of water in their workboat, dumping a half-million fingernail-sized oyster seedlings out of plastic buckets into about 30 feet of water.

The oysters take about two years to grow large enough for harvesting, but Relyea wonders if he’ll still be in business by then. That’s because the National Marine Fisheries Service is considering adding the Eastern oyster to the federal list of threatened or endangered species, a move that could devastate oystermen like Relyea.

“Sure the oyster industry is not nearly as big as it used to be, but the oysters aren’t going to become extinct,” Relyea says on a spectacular autumn afternoon as he plies waters where Theodore Roosevelt once fished and where Billy Joel’s mansion sits near the shore. “And if we manage them properly, it’s going to be a thriving farming operation.”

The federal review was prompted in large part by the situation in Maryland’s Chesapeake Bay, which has seen a dramatic drop-off in oyster numbers in the past several decades. Between the 1930s and 1970s, Maryland’s annual oyster harvest ranged between 2 and 4 million bushels a year. Last year, that number dropped to less than 33,000 bushels.

But the Chesapeake is not the only concern.

The Fisheries Service, which is part of the National Oceanic & Atmospheric Administration, said U.S. Atlantic Coast landings of Eastern oysters dropped from 160.6 million pounds in 1890 to 2.4 million pounds in 2003 – a trend believed to be driven by overfishing, lost habitats and disease.

Making matters worse, vast areas of the oyster industry in the Gulf of Mexico – one of the nation’s top producers – were damaged by Hurricanes Katrina and Rita.

“Oysters can tolerate wide variations in the environment, but preliminary data suggest that their numbers have declined significantly, possibly due to both harvest and disease,” said William T. Hogarth, assistant administrator for NOAA Fisheries Service.

A preliminary decision on the designation is due in January, although Fisheries Service official Marta Nammack said it could be up to two years before anything becomes final. She also noted that the oyster could be designated as “threatened,” rather than “endangered,” which would allow the agency to tailor regulations to specific parts of the country where the problem is more acute.

Relyea says that is part of the reason oyster farmers like him are concerned; it is not clear exactly what the ramifications of either federal designation could mean for them.

“We don’t know how the federal government would regulate our growing of oysters on the bottom of the bay,” said Relyea, a co-owner of Frank H. Flower & Sons – the state’s oldest and largest oyster-farming company. “That’s oyster habitat. They may say you can’t disturb oyster habitat and that would put us out of business.”

Another concern is how people at the dinner table would react. “People would think “how can you eat an endangered species?”‘ Relyea said.

At a congressional hearing in July, Long Island Farm Bureau director Joseph Gergela testified that the federal government might have it all wrong. “Where I come from, farmers, baymen and fishermen are the endangered species,” Gergela told lawmakers.

That was not always the case on Long Island and especially in Oyster Bay, which received its name in 1639 from a Dutch sea captain who was impressed by the abundance of the tasty bivalves. The story, according to Gergela, is that when he arrived, the captain discovered huge mounds of oyster shells, obviously the result of many years of feasting by Indian tribes.

At its peak, there were 150 companies working in the Long Island Sound with hundreds of boats and thousands of workers. But by the 1960s, the number of boats and companies dwindled to about a dozen; increased pollution from commercial and residential development were leading causes.

That is when Flowers & Sons began its aquaculture hatchery. It leases about 1,800 acres in the bay for the farming of oysters and clams. It is now the only oyster company remaining on Oyster Bay, and accounts for 90 percent of all oysters harvested statewide annually, Relyea said.

The seedlings are the product of an elaborate growing program at the operation’s hatchery in nearby Bayville. Oyster larvae are cultivated in large barrels of bay water that are eventually transferred to a nearby floating dock. Once they grow to about an inch-and-a-half, they are brought out into the bay, where they are left to grow for about two years.

Relyea says despite all that effort, his company only gets about a 30 percent return on the oyster seedlings; many fall victim to predators, but others drift beyond the designated planting areas and populate the entire bay.

“The benefits of it being farmed through aquaculture is that it’s actually coming back,” Gergela said. “In our waters, in particular, the oyster is doing well and is actually coming back in the wild more and more over time.”

One of the highlights in town is the annual Oyster Festival, slated this year for Oct. 15-16. Billed as the “biggest street fair on Long Island,” it attracts as many as 150,000 people and helps boost the local economy by $2.4 million, according to festival organizers.

More than 30,000 oysters will be shucked and served during the two-day event, said Relyea, whose company supplies the oysters.

“Come on down,” he said as he steered his workboat toward shore. “I’ll see you at the shucking contest.”