A blue mussel farm in the waters off Chilmark will soon double as a two-year kelp-growing experiment, following the lead of about a dozen other farms in the Northeast that have begun growing kelp in recent years.

The Chilmark selectmen on Tuesday gave final approval for the project, which is funded by the National Oceanic and Atmospheric Administration, with support from the Woods Hole Oceanographic Institution and the Martha’s Vineyard Shellfish Group. The shellfish group also maintains a small kelp-growing experiment in partnership with Cottage City Oysters in Oak Bluffs.

WHOI scientist Scott Lindell, who has worked with the shellfish group and local shellfish farmers for years, said the first sugar kelp lines in Chilmark would be in the water before December.

Stanley Larsen, a longtime commercial fisherman and owner of the Menemsha Fish Market, took over the blue mussel farm last year from Alec Gale. He later approached Mr. Lindell, who was involved in getting the blue mussel project off the ground 10 years ago, about the possibility of adding kelp to mix.

The project aims to demonstrate the benefits of growing multiple crops in a single area, and to help advance the marine aquaculture industry. Mussels and sugar kelp are among the fastest growing sectors of marine farming in the Northeast, according to a proposal presented to the selectmen, and both involve the use of long lines suspended below the surface. The proposal lists a number of benefits to growing the two crops together, including shared costs, more efficient use of space and less risk to protected species that might get entangled in the lines.

An existing 250-foot line strung between buoys and anchored to concrete blocks on the sea floor will be lowered to make room for kelp on a new line directly above it. The kelp line will come within about three meters of the surface, which Mr. Lindell said was deep enough not to interfere with boats.

Mr. Larsen said his four workers would be able to handle the new duties, which will include periodic thinning of the crop and annual harvests in April. A second phase of the project, beginning sometime next year, will test a new technique that involves multiple lines side by side, according to the proposal.

A renewed interest among chefs and health advocates has increased the viability of kelp growing in recent years. Selectman Warren Doty recalled a recent stroll at Lucy Vincent Beach, where he tasted some sugar kelp that had washed up on the shore. “It was not young and tender,” he said, although he could appreciate the culinary potential. Mr. Lindell said the product tasted just as good frozen as fresh.

The fast-growing plant could help remove excess nitrogen and other nutrients from the water, and be used as a biofuel and fertilizer. As filter feeders, mussels also help clear the water, which in turn could help the kelp photosynthesize. The proposal notes that mussels excrete ammonia, which could help nourish the neighboring crop.

The selectmen unanimously approved the proposal, agreeing to send a letter of endorsement to the state Division of Marine Fisheries.

In other waterfront business, selectmen heard a report on a recent exercise that involved a simulated oil spill and coordinated response in Menemsha Harbor. Bret Stearns, director of the Wampanoag Tribe’s natural resources department, said it was the first exercise of its kind on the Island to demonstrate that during an incoming tide, an oil spill could be corralled into the West Basin for removal.

Town officials from Chilmark and Aquinnah, along with commercial fishermen, members of the U.S. Coast Guard and others, spent the afternoon last Wednesday deploying floating booms across the channel, building on a similar drill in 2013 during which participants had struggled unsuccessfully against the tide.

All agreed that the drill, sponsored by the Department of Environmental Protection, was a significant improvement. After assembling 50 and 100-foot sections of boom, participants were able to direct a floating mass of peat moss (standing in for the oil) to the Aquinnah side of the channel.

“That’s not an appealing concept,” Mr. Stearns said of the strategy. “But oil response is making a horrible situation less horrible.” In an actual event, he said, off-Island boats would eventually arrive to vacuum up the spill.

“When it’s a windy day and there is any kind of a tide, this is a hard job,” Mr. Doty said of the response, stressing the importance of training and praising those involved in the drill. Chilmark fire chief David Norton shared the sentiment, but added a note of caution: “I think in the real phase, you’ll be lucky to get that many people,” he said. He also cited some needed improvements in the area of communication.

Selectman Jim Malkin noted the dangers of working in the channel when the tide is running, and asked who would be in charge in an emergency. Chilmark executive secretary Tim Carroll said that role usually falls to the fire chief, but in Mr. Norton’s absence, others should be ready to step in. Selectman Bill Rossi pressed for a written chain of command in the event of an actual spill.

“It’s not going to be pretty,” Mr. Malkin said.

Nuka Research and Planning Group, an environmental consulting firm that helped administer the classroom and field exercises last week, will now update its Geographic Response Plan, which details where to place a boom in the event of a spill. Mr. Stearns has asked the company to develop recommendations for better equipment as well, since he said the 12-inch booms now in use were twice as thick as necessary. He said he hopes to use the recommendations as leverage in applying for funding or federal supplies.

Mr. Stearns said a video of the drill would soon be available on the natural resources department website.