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Knotty Discussions Over Weak Points in Final Whale Rule

In July, the National Marine Fisheries Service (NMFS) published the Final Environmental Impact Statement (FEIS) with NMFS’s preferred alternative for the whale rules, which will amend the Large Whale Take Reduction Plan. While this is not the Final Rule, it provides a strong indication of which measures will likely be in the Final Rule. As expected, the FEIS preferred alternative would require lobstermen to insert 1,700-pound weak points in their vertical lines. Including weak points that break at 1,700 pounds of force, according to NMFS, will allow most right whales to break free of the line relatively quickly if they encounter vertical lines.

Weak links will be a knotty situation for a while yet. Emily Sawchuck Photography

Many lobstermen have asked what exactly constitutes a weak point or weak rope. The Department of Marine Resources (DMR) has spent the last three years working with lobstermen to identify operationally feasible solutions to weaken rope to this standard. DMR then tested and amassed data to document which methods meet the requirement. Erin Summers, DMR director of biological monitoring, oversees the department’s efforts.

“We’ve tested different manufacturers and diameters of rope, different ways to splice, and different types of knots to evaluate ways to reduce the breaking strength of lines already used in the lobster fishery. We’re working with companies on manufacturing plastic weak points that can be inserted in the rope and run through the hauler. NMFS will use the data we provide to decide what will be on the approved options list ,” Summers said. DMR developed the protocols for the tests of various weak-point connection types, which are now being used by all the states and NMFS. “Our goal was to allow lobstermen to use existing gear with weak points, rather than everyone having to buy new and experimental ropes,” she said. That meant finding ways to make rope typically used by Maine lobstermen break at 1,700 pounds.

Rope manufacturers are not currently making fishing rope that specifically breaks at 1,700 pounds unless it is a very small diameter, which adds to the urgency of developing practical weak points to comply with the implementation date of the rule when it comes out.

One of the simplest ways to weaken a fishing line is to put a knot in it. Most lobstermen either knot or splice rope together to transition from sink rope at the surface to float rope at the bottom of the vertical line, to alter its length as they move their traps throughout the season, or for gear maintenance at sea, thereby inevitably weakening their line. Yet the current whale rules require ropes to be as knotless as possible, pointing to the risk that a knotted rope might get jammed in the baleen of a whale.

While NMFS acknowledges that Maine DMR has demonstrated that “splices and knots introduce weakness into buoy lines,” the agency conducted an expert review this summer to determine whether using knots as weak points poses additional risk to right whales. NMFS convened an advisory group in three virtual meetings this summer on the subject of knots and their potential risk to whales during an entanglement. That advisory group will make a recommendation to NMFS later this fall on whether or not knots may be used as an authorized weak point to comply with regulations in the Final Rule.

Some Massachusetts lobstermen use a weak point sometimes called a South Shore sleeve. The sleeve is a hollow braided rope that is fed over the top of regular fishing line that has been cut. The sleeve tightens as it pulls against the two ends of the cut rope and is designed to break at the required pressure. According to Summers, the few lobstermen in Maine who have tried the sleeve experienced problems with the rope slipping. The sleeve also has difficulty working properly when attached to two different diameter ropes. “It hasn’t gained traction here,” Summers said.

Additional research conducted by DMR placed load cells on lobster boats to determine the hauling strain of gear. The results have led DMR to conclude that putting 1,700 pound weak points in the bottom half of the vertical line is not safe for many fishermen while hauling. The department is also working with marine companies to create molded plastic weak points (about the size and shape of a 1”chain link) that will pass through a hauler without problems and will break at 1,700 pounds.

“We are looking at simple solutions that lobstermen can use. We are gathering enough data so that those will be approved by NMFS,” Summer said. “The breaking strength data and field testing with fishermen in Maine go a lot further in these discussions than all the anecdotes in the world.” The Final Rule was published on August 31 and gives an implementation date of May 1, 2022. The issue for lobstermen, however, is when a list of approved weak points will be completed.


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