Lobstermen trace the route of a proposed undersea cable between Monhegan Island and Boothbay Harbor during a protest on Sunday. Maine Coast Fishermen’s Association

The seabed survey for a cable that would connect the planned offshore wind turbine near Monhegan Island to the mainland was disrupted Monday morning by three fishing boats that circled the survey vessel, according to New England Aqua Ventus, the project’s developer.

The action led the crew of the 144-foot R/V Go Liberty to suspend operations for an unspecified period, New England Aqua Ventus said.

“It was creating an unsafe situation until it’s resolved,” Dave Wilby, a project spokesman, told the Portland Press Herald.

The incident follows a protest Sunday by more than 80 lobster boats that lined up between Monhegan and Boothbay Harbor to call attention to their concerns about potential wind power development off the Maine coast.

Lobstermen fear that the ongoing survey project and the test turbine that would follow it will disrupt fisheries and undermine a traditional industry that is a vital economic engine for coastal Maine. But the project also is critical to Maine’s ambitions of jump-starting a new clean-energy sector.

After years of planning, a collaboration between the University of Maine and New England Aqua Ventus would link a turbine south of Monhegan to the mainland power grid in South Boothbay via a 23-mile underwater cable. The 12-megawatt test turbine would be the first commercial-scale project in the nation and help demonstrate the viability of floating offshore wind energy.

Details of what transpired along the survey route on Monday were hard to confirm and some key elements were in dispute. What is clear is that the events added to long-simmering tensions between fishermen and project developers.

Cellphone video taken from the Going Deep, a lobster boat out of Waldoboro, and posted on Facebook shows the Go Liberty on a heading to what Larry Reed, the boat’s captain, says is lobster gear.

“He’s going to tow right through the lobster gear with no concern,” Reed narrates in the video while panning to show buoys bobbing in his boat’s wake.

Reached at sea Monday afternoon, Reed said he only had a minute to talk but remarked: “I just didn’t like them towing toward my gear.”

Wilby said the Go Liberty alerted the Maine Marine Patrol and U.S. Coast Guard when the lobster vessels got close. A spokeswoman for the Coast Guard in Boston said a crew was dispatched out of Boothbay Harbor at the request of the Marine Patrol, but couldn’t confirm what, if any, incident had occurred.

The Department of Marine Resources and the Marine Patrol were still assessing the situation Monday afternoon, said Jeff Nichols, a spokesman.

GEAR ON SURVEY LINE AN ISSUE

Also in dispute is the presence of lobster gear along the survey route. Gear in the water could get tangled in the survey equipment, damaging both traps and expensive electronics.

Starting last month, the Department of Marine Resources and New England Aqua Ventus began reaching out to area fishermen with the route coordinates and requests that gear owners remove their equipment prior to the survey start date.

According to a gear density survey conducted on March 13, a total of 221 buoys were recorded, concentrated near a conservation area off Monhegan, Moser Ledge and the mouth of the Damariscotta River. The survey company then sent an email update to fishermen and posted a list of coordinates on the Aqua Ventus website, with a request to remove the gear.

On Saturday, the survey company ran a second reconnaissance survey and found 453 buoys, roughly double the number from a week earlier.

“The vessel cannot tow equipment and cannot proceed with the survey,” the survey vessel owner, Fugro Marine, said in a statement.

Lobstermen allege that the survey vessel hasn’t been staying precisely on its route, a charge denied by Aqua Ventus.

Wilby was asked Monday if the proliferation of gear along the survey route indicated that lobstermen were deliberately adding buoys to disrupt the survey.

“The facts speak for themselves,” he said of the doubling of gear along the route.

Monday afternoon, Wilby said he had just gotten a new report from the Go Liberty that the crew had observed fishing boats placing new gear in front of the survey vessel.

At roughly 4 p.m. Monday, the Go Liberty was moving at around 5 knots on a northerly heading, roughly along the survey route west of Monhegan, according to real-time vessel tracking at MarineTraffic. The tracking information shows the vessel tracing the route line, but also deviating in loops on either side of the path.

Gerry Cushman, a lobsterman who fishes out of Port Clyde on the 41-foot Bugcatcha, said he had joined the protest run on Sunday. On Monday, he was hearing reports of boats circling the survey vessel but didn’t have any details.

“I hope they are doing it as peacefully as possible,” he said. “We’re at war with the windmills, but I don’t want fishermen to look bad. We’re not the bad guys.”

NOT AWARE OF COORDINATED EFFORT

Ben Martens, executive director of the Maine Coast Fishermen’s Association, said he wasn’t aware of any coordinated effort to disrupt the survey. He said, however, that he had spoken to fishermen who said they had taken gear out of the survey route, but that it was damaged, anyway.

He also said he heard from fishermen that a boat that was reportedly “in the way” of the survey vessel was actually just working and hauling out gear.

“Disrupting the survey doesn’t solve anyone’s problems,” he said. “Sunday’s protest was a way to make the public aware in a peaceful way. We believe the public needs to know more about this and will side with fishermen and the environment.”

Rep. Genevieve McDonald, D-Stonington, a lobster fisher who also is working as a consultant for New England Aqua Ventus, said it was her understanding that not enough gear had been removed from the route for the survey vessel to do its work.

McDonald said the deteriorating relationship between fishermen and the project developers is unfortunate, because without a complete survey, it will be hard to develop the best route and minimize any impact on the fishing industry.

“There’s tremendous opposition to offshore wind among commercial fishermen,” she said. “The survey is the first tangible evidence of it and fishermen are responding to that.”

Project developers plan to begin construction in 2022 and have the turbine on line in 2023. The developers say the turbine will generate $125 million in economic activity and provide hundreds of jobs while the construction takes place.

The project has received $47 million in grants from the U.S. Department of Energy, which was augmented by another $100 million last August when it was joined by Diamond Offshore Wind, a subsidiary of Mitsubishi Corp., and RWE Renewables, an international wind company.