Shellfish Spawn as Montauk Sleeps

Eight weeks of coddling in the heat of the hatchery, and they’re ready
John Dunne, director of the East Hampton Town Shellfish Hatchery
John Dunne, director of the East Hampton Town Shellfish Hatchery, inspected larval oysters at the hatchery on Fort Pond Bay in Montauk. Christopher Walsh

John (Barley) Dunne reached into a large container and gently scooped a fraction of its contents. What looked like wet sand, perhaps 100 grains, stuck to his fingertips as he withdrew his arm.

The “sand” was, in fact, larval oysters, each no more than a millimeter in length. Those on Mr. Dunne’s fingers represented but a fraction of the container’s contents. The container was one among many in a hot, humid room at the East Hampton Town Shellfish Hatchery, where Mr. Dunne is the director, and the room itself is but one component of the hatchery’s infrastructure.

“These were spawned Feb. 18 or so,” Mr. Dunne explained this week. “About two weeks after spawn, they were introduced to these tanks. By July or August, these oysters will be about 40 millimeters.”

By that time, they will have been transferred to the hatchery’s nursery in Three Mile Harbor. “They’ll be living on the ambient water at the nursery site, and they’ll grow like crazy once the water reaches a certain temperature,” Mr. Dunne said. “They’ll double and triple in size and volume over the course of a week.”

Before any of that can happen, though, the hatchery’s staff must perform the essential work of spawning millions of larval clams, oysters, and scallops in the lab-like setting.

In 1989, four years after algal blooms began sweeping through local waterways and decimating the shellfish population, East Hampton Town established the hatchery, in a remnant structure of the Navy’s World War II-era torpedo range on the shore of Fort Pond Bay in Montauk. Long before the hamlet stirs from its winter slumber, Mr. Dunne and a staff including Kate Rossi-Snook, Peter Topping, James Duryea, and Jeremy Gould are well into another season’s work. The fruits of their labor supplement the existing shellfish stocks, allowing a bountiful harvest for town residents and a boost to the local economy.

Their task, Mr. Dunne said, is to grow “as many shellfish as possible every year, grow them to seed size, and then seed them out throughout the whole town.” Seed-placement sites include Northwest Harbor, Three Mile Harbor, Hog Creek, Accabonac Harbor, Lake Montauk, and Napeague Harbor. “In general,” he said, “it’s been great.”

It would seem a dream job for the former Peace Corps volunteer, who spent three years in the South Pacific’s Solomon Islands, where he and his wife worked on a pearl oyster farm. “It was incredible,” Mr. Dunne, who has been with the hatchery since 2004, enthused. “That’s how I got interested in shellfish.”

In Montauk, the process begins with the taking of a small quantity of clams and oysters from the wild during the winter. They are acclimated and put into a conditioning tank filled with water heated to a springlike temperature of around 60 degrees, and are fed a constant liquid diet of micro-algae, also grown on site. Mr. Dunne described the process as “eight weeks of coddling, and they’re ready to spawn.”

From there it’s on to the hatchery room, the hot, humid space where the bivalves are put into a summerlike water temperature. “They go from spring to summer like that,” Mr. Dunne said, “and their natural inclination is to spawn, because in the wild, during that time of year the bay water will reach that temperature, which equates to tons of food in the water.” It also equates to abundant predators, he added, including crabs, toadfish, and gulls.

The shellfish mass-produce sperm and eggs, with a large female oyster producing as many as 100 million eggs and a large clam about half as many. Mr. Dunne and his staff will condition just 25 to 30 of each species. “If we get a minimum of four females to spawn, that’s usually enough,” he said. Within a day, “We’ll have swimming larvae.”

The larvae are cultured in 100-gallon conical tanks, each containing millions of individuals. Three times a week, the tanks are drained and the larvae size-graded through a fine mesh sieve. The slower-growing larvae are culled from the group. “The idea is to get them as large as possible as quick as possible,” Mr. Dunne said. “They will out-compete each other for food, so we want to keep the big guys separate from the smaller guys.” The water, owing to the static environment, is changed during this process.

When the larval oysters reach a certain size they are set on tiny bits of shell. “When oysters set, they cement themselves to a substrate,” Mr. Dunne explained. “After that, they have no ability to move, which is really important later on when it comes to seeding and how they’ll survive in the wild.” Clams, he said, simply fall to the bottom when they set. In the wild, “they would use their rudimentary foot and drag themselves around, looking for a place to burrow. We set those on the bottom of a tank.”

Scallops, more sensitive and difficult to grow, are allowed to condition on their own in the wild. “We overwinter them and seed them in the spring,” Mr. Dunne said. Late in the spring, some will be brought into the hatchery for spawning. “It’s a later spawn, but they grow at such a rate that they’ll be a nice silver-dollar size come October, November.”

The team plans three spawns of oysters and clams each year, and aims for six to eight million oysters and some 20 million clams. The metamorphosis from larval to setting stage, Mr. Dunne said, is a stressful process; many will not survive it. “We get about four to five million per spawn, at best. Usually it’s more like three, but this year we seem to be off to a better start. We might meet our goal in two spawns. The third will be extra.”

Survival in the wild is another story. “When they’re in the larval stages, there’s tons of stuff out there eating just that,” Mr. Dunne said. “They’re basically a form of zooplankton. Once they settle to the bottom, they’re so small, and the bottom is covered with crabs and other crustacean-eating fish.”

Once seeded in the wild, Mr. Dunne estimates a 50 percent survival rate for oysters and 20 percent for clams. “It’s still a lot of shellfish,” he observed, “more than enough for people to go out there and make their limit.”

The program is successful, and the hatchery director is grateful for the support of the town board and the East Hampton Town Trustees, who oversee the waters that are seeded each year.

“Shellfishing is a huge part of the culture,” Mr. Dunne said. “We’re lucky that we have a lot of support from the town board and the public.”