Scientists say lobster traps are in wrong place for right whales

ROCKPORT — Last summer, at least 17 endangered North Atlantic right whales died during their northward migration from their spawning grounds off the coast of Florida and Georgia. Of those, 12 were found dead in Canadian waters, while five were found off the coast of the United States.

Besides the whales that died last year, several more were found entangled in fishing gear and at least one more whale died in January of this year.

Now scientists and fisheries regulators are working to find ways to reduce the risk of entanglement, and may implement changes in fishing rules that have an enormous impact on Maine’s lobster industry.

The NOAA Fisheries Large Whale Take Reduction Team recently established separate working groups to study two proposals to reduce the risk of entanglement: splicing several 1,700-pound breaking strength “weak link” sleeves into vertical lines such as those that connect lobster buoys to traps; and removing those ropes altogether by requiring the use of “ropeless” fishing gear.

Those working groups will focus on whether either solution is technologically feasible, whether it will actually work for fishermen and whether it can be cost-effective for fishermen.

According to scientists from NOAA Fisheries and the New England Aquarium in Boston, the evidence suggests that the already tiny right whale population is declining.

Speaking at the Maine Fishermen’s Forum on Friday, David Morin and Mike Asaro, both of NOAA Fisheries Greater Atlantic Region Fisheries Office in Gloucester, Mass., presented some alarming figures.

In 2011, the right whale population stood at 481, but five years later it was just 458 despite the birth of 77 calves during the five-year period. That works out to 20 whale deaths, and about 15 whale births, each year on average.

With calculations showing that adult breeding females make up 23 percent of the population — about 105 whales — scientists believe there could be no breeding females left, and accordingly no more whale calves, within 23 years. And whale births are already in decline. What’s more, Asaro said, while 17 whales died last year, only five calves were born in 2017, a sharp decline from previous years.

Several factors affect the whales’ declining birth rate. One is that changes in the environment have made it harder for whales to find enough food and so the females are not getting fat enough to bear calves. Another problem, Asaro said, is that females that become entangled in fishing gear take a long time to recover from their injuries — if they ever do — and delay having calves.

There seems to be no doubt, despite the lobster industry’s converting an estimated 27,000 miles of floating groundlines between traps to sinking groundlines in 2009 and the removal of some 2,740 miles of vertical buoy lines in the water required by new regulations imposed in 2015, that entanglement is still a problem.

Of the 17 right whale deaths last year, four were definitely caused by entanglement in fishing gear, compared with five resulting from ship strikes. Two of the whales that died as a result of entanglement, according to Morin, were recovered in U.S. waters. Between 2000 and 2015, deaths from ship strikes have declined sharply while those from entanglements have increased.

While most Maine lobstermen say they have never even seen a right whale close to the Maine coast, statistics collected by NOAA explain why right whales are exposed to a high risk of entanglement off the Maine coast.

Based on data collected by the Atlantic States Marine Fisheries Commission, there are some 2.9 million lobster traps in the water within 50 miles of the Maine coast. Even with an average of fewer than five whales per month passing through Maine waters, the density of gear makes the risk of entanglement very high.

With the whale population at such serious risk, and the federal Marine Mammal Protection Act requiring that fewer than one right whale per year may be killed, scientists at both the Woods Hole Oceanographic Institution and the New England Aquarium are working on ways to reduce the incidence, and impact, of entanglements.

Amy Knowlton from the New England Aquarium explained how she and her colleagues had studied the strain that lifting a trap trawl — a series of connected traps — place on the lifting line as well as the force generated by a moving whale. They have tentatively concluded that splicing 1,700-pound “weak link” rope sleeves into those endlines could protect the whales while still allowing lobstermen to retrieve their gear in most circumstances, even offshore.

Mark Baumgartner of the Woods Hole Oceanographic Institution described a system that used no vertical lines except when traps were actually being hauled.

“If you’re over 50, you’re going to think I’m crazy,” he told the packed hall. Younger fishermen, he said, already use far more complicated smartphones as a matter of course.

One design uses a spool of rope installed on the trap that is triggered by an electronic signal from a boat. Another design calls for inflatable bags, also triggered by a signal from the surface, that would lift the entire trap. No cost estimate was yet available for such a system but even at $30 per trap, a figure that was mentioned, a lobsterman with 800 traps in the water would face a $24,000 investment.

Baumgartner also didn’t explain how fishermen using the ropeless system could avoid gear conflicts without knowing where traps were already set.

Whatever the working groups report, the Large Whale Take Reduction Team will likely meet in the fall to review the options to reduce gear entanglements.

Stephen Rappaport

Stephen Rappaport

Waterfront Editor at The Ellsworth American
Stephen Rappaport has lived in Maine for nearly 30 years. A lifelong sailor, he spends as much time as possible messing about in boats. [email protected]