SCARBOROUGH — Abigail Carroll would never have guessed that as a former trader in the Paris stock market, she would eventually start her own oyster farm in the waters off southern Maine.

After ending a relationship, leaving France and moving back to Maine for the summer, one of Carroll’s friends wanted to start an oyster farm and Carroll agreed to help, not knowing she would adopt the career herself.

“It was really quite accidental,” Carroll, a Portland native living in Biddeford, said Tuesday morning as she meandered her small motor skiff around moored lobster boats toward her lines of oyster bags.

Now in her fifth year of operation, Carroll and her small team of mostly volunteers for Nonesuch Oysters farm the mollusks in the brackish waters near the Pine Point Fisherman’s Co-op, where the incoming ocean tide meets freshwater from the Scarborough River.

The entire growth process is free-range and, while the farm is still in its nascent stages, Carroll said she’s “really excited; I think we found the solution to use less gear and let nature work its course.”

More than two years ago, Carroll applied to the Department of Marine Resources for permission to expand her site. A public hearing was held earlier this month, and she expects to receive the permit in the near future.

Nonesuch Oysters are farmed in an area totaling about 4 1/2 acres near the west side of the river. If an expansion is permitted, Nonesuch would have access to about seven acres along the western shore. In that additional acreage, Carroll would be able to do more ground seeding in deeper waters.

The goal, she said, is to have several long lines of oyster bags, rather than shorter, fragmented lines, which she now uses.

Carroll cultivates American Crassostrea virginica oysters and European Ostrea edulis oysters.

Most oyster farms in Maine harvest virginicas, Carroll said as she pulled two out of a submerged bag and held them in her hands; but remarkably, they can look and taste very differently, depending on the habitat.

Carroll uses the French word “terroir” to describe the direct relationship between how the environment affects the character of the item being cultivated. The term is used most often to describe the nuanced environmental distinctions between wine grapes, but it’s perfectly applicable to oysters, too, she said.

“An oyster is absolutely a product of its environment,” Carroll said, holding two oysters very different in appearance: one was smaller and white, and the other, larger and green. Both are virginicas, she said, but one had been pulled from a buoyant bag and the other from the ocean floor, a couple feet deeper.

Carroll likes to start her oysters in bags, where they spend the first years of their lives.

Near the end of their growing process, Carroll drops those oysters a couple feet lower, to the ocean floor. This exposes them to different environmental influences, and ultimately creates a blend of taste and appearance that varies from oyster to oyster, making them “more beautiful and robust,” she said.

During tours she gives on her boat during the warmer months, Carroll asks her customers what they think the terroir is in a specific area.

“We’re so close to the mouth of the ocean, you’ve got a lot of salt water at high tide,” she said. At low tide, the volume of fresh water and salt water shifts and the oysters are exposed to different vegetation with the reverse flow of water, like decomposing sea grass, and increased levels of sediment.

“I’ve had people tell me my oysters are the sweetest they’ve ever had, and I’ve had others tell me my oysters are the briniest they’ve ever had,” Carroll said.

“What I’ve learned about marine watershed ecology is that oysters are this amazing example of how susceptible marine creatures are to even a small change in their environments,” she said. “That just shows you how important this idea of terroir is to this industry.”

The role of oyster farmer is different than a land farmer, in that Carroll doesn’t directly feed the product she’s cultivating.

“We just want to create the water flow,” she said, so the oysters are able to ingest the water and plankton. “Nature works really well when you let it.”

Typically, oysters are harvested when they get to be between 2 1/2 and 3 inches in diameter. Oysters grown in Maine tend to grow about an inch a year, Carroll said, “but I think we can do better than that.”

The best harvest year since Nonesuch was founded in 2010 yielded about 100,000 oysters, Carroll said.

Consumers can find Nonesuch oysters in several Portland locations, including Eventide Oyster Co., Fore Street, Petite Jacqueline and Harbor Fish Market. Other southern Maine locations including Bayley’s Seafood and Ken’s Place in Scarborough, and Earth in Kennebunk.

Nonesuch also sells to Clio’s Restaurant and B&G Oyster Bar in Boston, and Grand Central Oyster Bar in New York City.

Carroll and her team didn’t cultivate any oysters this summer. Instead, they just conducted research that will eventually fill a handbook.

“We’re just setting up for the future,” she said. They began harvesting in mid-September and will continue until the waters become impassable due to winter ice.

In a 2013 TEDxYouth talk that Carroll gave in Biddeford, she said, “I never wanted to be an oyster lady, and I never thought I’d come back to Maine. But it’s ironic: by becoming an oyster lady, I’ve found a renewed sense of purpose.”

Alex Acquisto can be reached at 781-3661 ext. 106 or aacquisto@theforecaster.net. Follow Alex on Twitter: @AcquistoA.

Abigail Carroll, owner of Nonesuch Oysters, LLC in Scarborough, shows bags of oysters underneath a portion of the dock at the Pine Point Fisherman’s Co-op. Carroll started her oyster farm in 2010.

Abigail Carroll holds two free-range Crassostrea virginica oysters that have different appearances, highlighting the nuanced influence of environmental influences on the growing cycle of oysters. The white oysters has been raised in a bag and the green, in a bag for the first few years of its life and now on the ocean floor. Carroll practices this growing method with all her oysters because she believes it makes them “more beautiful and robust.”

Nonesuch Oysters, LLC has applied for an expansion through the Department of Marine Resources. Currently farming out of about four-and-a-half acres on the western side of the Scarborough River, near the mouth of the ocean, owner Abigail Carroll is seeking nearly three additional acres for farming.

Abigail Carroll, a Portland native and current resident of Biddeford, started Nonesuch Oysters, LLC in Scarborough in 2010 after moving back to the United States from Paris, France. “It really was quite accidental,” she said of starting her own oyster farm. Carroll is waiting for the Department of Marine Resources to determine whether to grant Nonesuch the go-ahead to expand its farming acreage.