A group of state researchers in Boothbay Harbor are testing how much force it takes to snap hundreds of pieces of rope apart as they try to identify knot combinations and configurations of fishing line that will help protect whales from life-threatening entanglements.

Since early 2019, the small group of scientists at the Maine Department of Marine Resources have been testing a variety of different types of rope knotted together by putting them under strain with an old hydraulic tensile testing machine. They do their work in a garage bay on the department’s property on McKown Point Road. They have gone through a couple hundred different combinations of used and new rope tied together in various knots, testing each combination 10 times to determine their breaking points. They expect to try more than 900 different configurations in all.

The idea is to come up with a way Maine lobstermen can affordably satisfy federal laws that prohibit fishing activity from harming protected marine species such as North Atlantic right whales, of which only 400 or so remain. Maine lobstermen have been awaiting a new set of federal rules aimed at preventing whale entanglements that would force them to change the gear they use for the third time in slightly more than a decade.

The Department of Marine Resources researchers are hoping to find rope configurations that fishermen can put together from their existing gear, saving them the expense and trouble of replacing all their gear in order to continue harvesting lobster from the Gulf of Maine, which last year generated $485 million in statewide fishing revenue.

State fisheries officials say the research will provide fishermen and federal regulators with information on how lobstermen can use rope already on the market to create breaking points in their vertical buoy lines that are weak enough so they part if put under strain by a whale. If lobstermen use rope that breaks when put under 1,700 pounds or more of stress, it could help to satisfy the expected new federal regulations.

Robert Russell, a scientist with the state Department of Marine Resources, holds several tagged sections of fishing rope at DMR’s regional offices on Oct. 2, 2020.  Credit: Bill Trotter | BDN

In response to a lawsuit filed by environmental groups, a federal judge ruled in April that the National Marine Fisheries Service was not doing enough to protect endangered whales and set a deadline of May 31, 2021, for the agency to adopt a final set of new rules aimed at preventing entanglements.

“All the serious injuries and mortalities to right whales have been with rope with rated breaking points greater than 1,700 pounds,” said Erin Summers, who directs the Department of Marine Resources’ fisheries monitoring and assessment program. “There are many factors that will determine when it breaks.”

The thickness of a rope, how long it has been used, how it is configured when attached to lobster traps and where on the ocean bottom it is deployed all affect how a rope deteriorates, she said.

Knotted rope is more likely to break when put under strain than a straight section of rope, or two sections of rope spliced together, because a knot in rope is already relatively taut and has less flexibility, said Robert Russell, a marine resource scientist with the department. The tight coil of rope that curves around in a knot is where it usually snaps when a rope is pulled taut by a heavy load.

“If you take a piece of rope and bend it, you are weakening it,” Russell said, standing among coils and small piles of knotted fishing rope on the garage floor.

But the rope can’t be too weak, or else it will break while fishermen are hauling their traps to the surface, Russell said, which could result in more so-called “ghost gear” being lost on the ocean floor.

Maine lobstermen configure their gear in several different ways. Some fish closer to shore, with fewer traps connected to each buoy, while those who fish farther offshore set more traps per line and need comparatively stronger rope. Lobstermen in eastern Washington County fish in stronger tides, close to the powerful Bay of Fundy, and so have their buoy lines under more constant strain just from the force of water than fishermen in southern Maine.

As a result of the scientists’ tests of various configurations and knots, fishermen might be able to find combinations that work in the areas they fish with the type of rope they already are using. Other possible options — such as a dense plastic ring called a “dog bone” that fishermen sometimes use to connect two sections of rope, or a baseball bat-shaped housing placed on a rope that will slice it in two if it is under strain for more than a few seconds — already are available or being tested.

Robert Russell, a scientist with the state Department of Marine Resources, holds a type of hard plastic ring informally called a ‘dog biscuit’ that fishermen sometimes use to link two sections of rope together.  Credit: Bill Trotter | BDN

Tying knots at certain points in rope they are already using is relatively easy for fishermen to do while moving traps at sea, Russell said. And it is less expensive than having to buy all new rope with lower breaking points.

“It’s not going to slow down your day that much,” he said, referring to tying knots in rope while hauling traps. “It’s using what you already have.”

Summers said there continue to be discussions and experiments in designing ropeless fishing gear — in which buoys would pop up from submerged gear via a remote radio signal — but that it currently is not a viable option and is not being considered as a federal requirement. A draft of the new rules is expected to be released “any day now,” she added.

Summers said that though the ropes fishermen buy are rated up to a certain strength, before the Department of Marine Resources started testing the breaking points of knotted ropes and other links, the industry did not know how easy or difficult it was for a whale to shed entangled gear. She said that the department wants to ensure that the new federal rules both improve protections for whales and give lobstermen a viable way to change the way they fish.

“We’re committed to have this be evidence-based, and to have everything in the process be data-driven,” Summers said.

The research being done by the department, and the goal of maintaining regulatory flexibility for what breakaway options fishermen can use, is “extremely important,” according to an official with Maine’s largest commercial fishing industry group.

If federal regulators allow fishermen to reconfigure the rope they already have with knotted breaking points, it will help reduce the overall threat from entanglements in the Gulf of Maine, said Patrice McCarron, executive director of the Maine Lobstermen’s Association.

Tighter limits on the number of vertical buoy lines in the water farther out from an exemption boundary line that runs roughly 3 miles offshore also are expected to be among the new restrictions, the stated aim of which will be to reduce the risk of entanglement in the Gulf of Maine by 60 percent.

“One size fits all will not work for Maine,” McCarron said. “Maine’s lobster industry is extremely diverse, so fishing methods that may work for some [lobstermen] are not viable for others.”

When the new federal lobster gear restrictions are announced, it will be the third time in the past decade-plus that Maine lobstermen have had to change the way they fish because of concerns about whale entanglements.

In 2009, fishermen were required to use sinking ground lines between traps on multi-trap trawls to eliminate floating arcs of rope rising up from the ocean floor. Five years later, federal regulators set a minimum number of traps for each buoy deployed outside the exemption line, with the minimum varying depending on how far out the gear is set.

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Bill Trotter

A news reporter in coastal Maine for more than 20 years, Bill Trotter writes about how the Atlantic Ocean and the state's iconic coastline help to shape the lives of coastal Maine residents and visitors....