Seaweed Could Be The Next South Fork Crop


They call kelp “the virtuous vegetable” up in Maine. Seaweed is good for you, what with its potassium and calcium and iodine and Omega-3.

Off the Connecticut shore of Long Island Sound, the Thimble Island Oyster Company now farms seaweed, and kelp accompanies oysters, clams and mussels in community-supported fishery shares just like the vegetables rewarding shareholders in CSAs. “Eating like a fish”—that is, eating seaweed—can ease pressure on fish stocks, according to Thimble Island’s website, which also notes that Manhattan restaurants are serving kelp linguine, kelp ice cream, even kelp cocktails, all using its harvest.

Not only is seaweed a sustainable food source, without the need for irrigation, land or pesticides, but it can remove nutrients such as nitrogen that promote excessive algae growth, improving the health of water bodies while removing carbon from the atmosphere.

Imagine South Fork farm stands and restaurants selling homegrown kelp harvested by local baymen, or by oyster growers who want to make use of the water above their shellfish beds. Is the farming of sea vegetables the next logical step beyond the cultivation of shellfish?

The answer depends on who’s giving it, considering a number of hurdles ranging from official certification to protecting the environment to finding a spot where seaweed farming could turn a profit without interfering with other activities.

“You’ve got some good opportunities there as long as the growers are able to get the proper permits from the Department of Environmental Conservation and also the Army Corps of Engineers. … You’ve got some excellent areas,” said Charles Yarish at the University of Connecticut in Stamford, who mentioned Montauk, the Peconic bays, Shelter Island and Long Island Sound as possibilities. A professor of ecology and evolutionary biology and an expert in aquaculture-cultivated seaweed, Dr. Yarish helped get kelp farms off the ground at both the Thimble Island Oyster Company and Ocean Approved in Portland, Maine, a former mussel farm that last year harvested more than 100,000 pounds of three native seaweeds germinated onshore and then set out on lines descending into the water.

“Once the kelp gets to about 1/2 to 2 millimeters long, then we move it into the open ocean,” explained Paul Dobbins, an owner of Ocean Approved. In 90 to 110 days the seaweed will grow to be anywhere from 9 to 12 feet long, with a harvest of about 33,000 pounds per acre. Ocean Approved sells most of its fresh-frozen product, which comes in cuts like “slaw,” “noodle” and “salad,” to restaurants and food service organizations. The Maine company—whose nutritionist, Stefanie Sacks, lives in Montauk—says its product is much more vibrant-looking and tasty than dried seaweed imported from Asia.

“Business is booming,” Mr. Dobbins said, adding that the company’s tillers of the ocean were “right in the middle of our seeding season” for next spring’s harvest.

“The rest of the world has done it, and now the U.S. is starting to catch up … globally, we are really behind the curve,” Mr. Dobbins said. “I believe aquaculture is how we’re going to feed the world’s population.”

Mr. Dobbins and Dr. Yarish led three workshops in New England on kelp farming this fall. Together, they drew 154 participants, including Joe Tremblay, who’s been involved in raising oysters in Sag Harbor and nearby through an “oyster club” of private individuals, the Cornell Cooperative Extension’s Southold Project on Aquaculture Training (SPAT) program and the Southampton Town Trustees.

“There was a lot of interest from people on Long Island,” said Mr. Tremblay, who attended a workshop at Roger Williams College in Rhode Island. “There’s a lot of potential.”

“I’m interested in growing seaweed because of so many of the problems we’re facing in our local estuaries,” he said, adding that he would like to find varieties that can be grown in smaller water bodies like Sag Harbor Cove where “you can make a difference” by using them to pull nitrogen out. Kelp requires colder water like that off Montauk, he said, also noting that a current impediment to farming sea vegetables locally is the lack of a mechanism for securing approvals from the DEC.

“The product is clean and it’s loaded with nutrients,” Mr. Tremblay said. “So the health food market for it is strong … a combination of Asian and health food markets.” One might combine farming shellfish or even harvesting sea salt with farming seaweed, he said. “I can definitely see someone selling this at farmers markets and everyone eating it right up.”

An owner of Bay Burger in Sag Harbor, Mr. Tremblay said he wasn’t sure that raising seaweed is “what I want to do with my life,” but pointed out that he already has an ice cream business—Joe and Liza’s Ice Cream—“so I’m already in the frozen food market.” If he doesn’t get involved, he said, he hopes that someone else will.

“Somebody’s going to do it, no doubt about it,” said Gregg Rivara, an aquaculture specialist with Cornell Cooperative Extension’s marine program. Mr. Rivara ticked off several hurdles to growing seaweed locally, however. Kelp grows relatively high in the water column because it needs sunlight, which means boats could run afoul of the lines on which the plants are cultivated, There would also need to be a way to guarantee that the water is pure enough to make the seaweed safe to eat, perhaps by making sure it comes from places already certified for shellfish. Also, seaweed growers would need permission to use bodies of water, which generally are owned by the public: shellfish farmers who have leases for bottomland couldn’t just tack seaweed-growing onto their approval, Mr. Rivara said: “It’s like saying I’m leasing the house from this guy and I want to start a tire store.”

On the other hand, he said the idea held small-scale promise for perhaps “10 percent of the existing 40 or 50 people involved in shellfish aquaculture” on the East End, potentially providing an opportunity to diversify for fishermen who already have boats and gear and others simply thinking about a startup business.

“I’m all for what you call water-dependent uses of the shoreline,” said Mr. Rivara, who used to gather seaweed in Montauk and hang it on his clothesline before mixing it into soups and other dishes. He pointed out, too, that seaweed has also been seen as a potential source of fuel and for pharmaceutical use for years.

There’s a long history to eating sea vegetables, but Americans really only started giving them a sniff in recent years, Mr. Rivara said. “You can get seaweed salad at most restaurants now. … I think it’s more of a niche market—there’s a cachet to it—just like local wine and beer,” he said. “I could see farmers carrying it at farm stands.”

Larry Liddle, a professor emeritus of marine science at Stony Brook Southampton, who has long studied seaweed, said the use of sea plants as “scrubbers” is already in place both in the Harlem River—in that case with the DEC’s permission to proceed experimentally—and in China, where Dr. Liddle has been working over the last three years with people who grow a red alga called gracilaria to remove nutrients and for use as food and as a gelling agent. He stressed that seaweed must be harvested if it is to remove nitrates; otherwise they will simply return to the water when the plants break down.

The kelp seen at Montauk Point is what the Japanese call kombu, an edible plant, although it’s at the southernmost point of its range and thus not as plentiful as it is to the north.

“I think the issue, the overall issue, is the problem of introducing any nonnative species to any area,” Dr. Liddle said of farming seaweed locally. “It might take over or something like that.”

Diane McNally, clerk of the East Hampton Town Trustees, expressed a similar concern, adding that the prospect of using Trustee-owned waters had not so far been raised. At one point they discussed “seeding” a community shellfish garden, she said, adding that growing seaweed might somehow be worked into that program if it comes to pass. The private use of a public resource like Trustee waters has traditionally been tricky, she said, adding that the county has been leasing bottomland in Gardiners Bay and wondering whether growing seaweed might “fit in more easily … in a scenario like that.”

Southampton Town Trustee Bill Pell, who works out of Shinnecock Bay, said he had explored the idea of farming seaweed years ago after seeing it done on the West Coast. “You need deeper water, colder water,” he said. “Our bays are warmer.”

Another Southampton Trustee, Ed Warner, said he sees very little kelp where he fishes, including in western Peconic Bay, essentially from Gardiners Island west to Flanders. “I do see codium, basically the spaghetti grass,” he said, adding that the native plants are likely to involve shellfish beds that had best not be disturbed.

But Dr. Yarish described the concept as “3D farming” where both the water column—with, say, oysters on the bottom and seaweed above—and the seasons can be exploited with greater efficiency. “Here’s another crop for the shellfish farmer,” he said. “And you’re doing valuable ecosystem services.”

He said a winter crop of sugar kelp would work particularly well in this area, growing from December through late April or early May, when recreational boats are out of the water and biological activity has slowed down. Fishermen or shellfish growers who own boats could grow kelp during their slow period, Dr. Yarish said, with the added advantage that the nutrients the seaweed removes are at their highest levels in January and February.

“So we’re doing very important ecosystem services, and just by growing a commodity that has potential as a sea vegetable we’re providing livelihoods,” Dr. Yarish said. “It’s good for the environment and it’s good for business, you’re giving people a good healthy commodity—and if you have a gluten allergy you can make a pasta that’s gluten-free.”

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