COREA, Me. — The boats start up around 3:30 in the morning, stirring the village with the babble of engines before they motor out to sea. They will return hours later, loaded with lobster.

Joe Young’s boat has not gone out lately. Instead, he puts on waders and sloshes into the salt pond behind his house, an inlet where water rushes in and out with the tides. After a lifetime with most of his income tied to what he finds in the sea, this lobsterman — and sixth-generation fisherman — is trying his hand at something new. He is farming oysters.

“Said I would never have a garden,” Mr. Young, 64, says, as he tends to his briny nursery. Tens of thousands of oysters the size of peanuts are growing inside porous boxes, stacked up like underwater file drawers, in a contraption called an “oyster condo.” He gives one of the boxes a shake, hoping to dislodge a slimy orange growth that has taken up residence, and flings away a green crab. Nearby, kelp he is growing sways lazily from a long underwater rope.

Reaching into the glassy water, Mr. Young plucks larger oysters from among the smooth stones, popping the mottled mollusks into a big white bucket.

“It’s different from lobstering,” Mr. Young said, “because I’m in the whole process.”

The idea of growing seafood, or aquaculture, is a new concept for this tiny fishing village in the town of Gouldsboro, population 1,700, in Downeast Maine. It is still a place where, as the writer Louise Dickinson Rich put it in 1958, “nothing — not the fall of governments or birth of kings or the discovery of new galaxies — is of so much importance and interest as the question of whether the boats will be able to go out today, and whether the lobsters will be crawling and the herring shoaling.”

The lobsters certainly have been crawling in recent years.

“Poundage-wise, it’s just been going up and up and up,” said Michael Hunt, the president of Corea’s lobster cooperative, which buys lobsters off the boat and generally sells them to distributors — and to Mr. Young, who also has a cafe on the dock where he sells lobster rolls, lobster dinners and, now, his homegrown oysters.

In some parts of the state, aquaculture has met with resistance over how it might block access to the water and other issues. But a growing number of people in Maine are trying it. The state’s Department of Marine Resources said the number of licenses for small aquaculture operations in this state had more than doubled in the past 18 months, to 415. There are another 126 larger farms, which can be as big as 100 acres. New growers have much to learn, and the state is considering requiring them to take a course on shellfish handling and health.

Some people have turned to farms because they were unable to get state permission to fish in waters where they had hoped to. Others, like Mr. Young, want to diversify their sources of income, which could prove useful in an era of warming waters and a changing climate.

“Lobstermen are saying, ‘Boy, not only personally, but community level, we’re all invested in lobsters,’ ” Jon Lewis, the director of the state’s aquaculture division, said. “ ‘Natural resources tend to come and go. If this happens, what do I do?’ ”

Still, plenty of them are skeptical when there remains so much lobster to catch.

The recent success of the lobster fishery has fed optimism and investment in larger boats that have changed the feel of the village. “The boats are getting bigger and the harbor’s getting smaller,” Marianne Urquhart, who is in her 70s, said.

But there is anxiety, too, particularly at moments this summer when it seemed as if the lobsters were slow to show up.

“There used to be paper mills, there used to be sardine factories — now there’s just lobstering,” said Todd Knowles, 49, a third-generation fisherman from Gouldsboro who was watching miniature lobster boats ride down the street during a parade in nearby Winter Harbor, where he fishes.

Scientists suggest that the bounty cannot last forever. The Gulf of Maine is changing, its waters heating up faster than nearly anywhere else on earth. This has helped the lobster flourish, in part because the warmer waters are inhospitable to a key predator, cod, which have also been heavily fished. But as warming continues, scientists say, it could be harder for baby lobsters to survive, and easier for shell disease to take a toll.

“We can’t depend on the natural wild fisheries to keep on performing year in and year out — it’s not going to happen,” said Boe Marsh, who deals and processes seafood in Bremen, Me., and who is, with the help of a local lobsterman, growing 130,000 oysters on the water there.

On smaller boats in Corea, the old ways go on. Jean Symonds, 84, steers her lobster boat, Finest Kind, out of the harbor around 5 o’clock on a misty morning. Cadillac Mountain — the highest point in Acadia National Park — peeks out through fog. Ms. Symonds works with Donald Crowley, 65, to hoist traps up from the sea floor with a pulley and take the lobsters that are big enough to keep.

“Last time we hauled here, we had a barrelful,” Ms. Symonds said. “Not today.”

As Ms. Symonds guides her boat back to the co-op, a much larger lobstering vessel glides past.

To Mr. Young, aquaculture does not look so different from catching lobsters. “Fishermen are farmers,” he said. “There’s one crop, and it’s lobster.” Aquaculture comes with its own set of uncertainties, as Mr. Young found in September when the authorities issued a temporary ban — which has since been lifted — on harvesting his oysters because of rainfall, which can put new pollutants in the water. From time to time, closures due to biotoxins in the water also limit shellfish harvesting in parts of the state.

At the wharf, Mr. Young keeps a gallery of photographs taken by his aunt, Louise Young, who died in 2004. These glimpses of Corea in the 1940s, 1950s and 1960s reveal a time when small boats were packed not just with lobster, but also with cod, pollock and herring.

“Look at what you see here in the photos, and how much of that’s gone,” Mr. Young said. “What if 50 years from now, what we have now is gone? And it’s oysters and mussels and kelp?”