Right whale mortalities put spotlight on Canadian crab fishing

There is a different type of whale-watching taking place in Atlantic Canada. This watch isn’t for the pleasure of tourists, but the survival of the North Atlantic right whale as a species. 

In a typical year, three right whales might be found dead. In 2017, 15 of the whales are known to have died. Two were found off Massachusetts, nine in the Gulf of St. Lawrence and four off Newfoundland. Five live entanglements were also documented in Canadian waters.

Necropsies were conducted on six of the Gulf of St. Lawrence whales and a 219-page “Incident Report: North Atlantic Right Whale Mortality Event in the Gulf of St. Lawrence 2017” was issued. 

The report concluded that four whales died from acute trauma, which indicates vessel strikes. One whale was confirmed to have died from chronic entanglement in fishing gear and one could not be determined because of advanced decomposition. No evidence was found to support the involvement of biotoxins, infectious diseases, or starvation as the primary causes of mortality. 

The deaths are significant because the North Atlantic right whale has been dangerously near extinction since the 1930s. At its lowest level, the right whale population was down to 300 animals. At the beginning of 2017, scientists believed the population numbered 500, but in September scientists from the National Oceanographic and Atmospheric Administration determined there were 458 right whales remaining. That determination made before the current spate of deaths occurred, which would reduce the actual population to 444 whales – this year’s death count represents three percent of the known right whale population

Tony LaCasse, media relations director for the New England Aquarium in Boston, verified NOAA’s estimate.

“Every right whale in the Northwest Atlantic has been catalogued. The New England Aquarium has a catalogue of all the known individuals” based on “sightings and photographs and other information,” LaCasse said. “We have hundreds of thousands of entries for different right whales going back to the 1930s. So that’s a very comprehensive population directory maintained by us on an ongoing basis.”

As the right whale mortalities mounted this summer, Canadian Minister of Fisheries and Oceans, Dominic LeBlanc, closed Eastern Canada’s snow crab fishery two days early. This was done because two of the dead whales were found entangled in crab gear and five live whales either showed cuts, lesions and scars caused by gear entanglement or were still entangled. 

The right whales’ appearance in the Gulf of St. Lawrence has scientists baffled, as the area is not their traditional feeding ground. Normally, the whales spend their summers in the Bay of Fundy, which has less intensive shipping. The Gulf, on the other hand, has a high volume of shipping and marine traffic, since it connects central and Eastern Canada to international shipping lanes.

Part of finding a solution to ensure the safety of the right whales requires more research into their shift to the Gulf from the Bay of Fundy and then, as the mortality report calls for, developing and implementing conservation measures specific to the area. 

To further reduce the potential for vessel strikes, Canadian Minister of Transportation Marc Garneau, set a mandatory 10-knot speed limit for all vessels over 20 meters (65 feet) in length and a voluntary 10-knot limit for smaller vessels in the Gulf of St. Lawrence. The speed limit will be lifted once the right whales migrate back to their winter waters, Garneau said in his announcement. As a result of the lower speed limit, nine cruise ships cancelled calls on Charlottetown, Prince Edward Island, in an effort to keep to their schedule.

Despite the economic hit the region took due to the lowered speed limits, Matthew Hardy of the Science Branch of the DFO said they remain an important tool in preserving the North American right whale.

“Regarding 2018, it's early to speculate, but speed restrictions remain one of the options in the toolbox which is known to be effective,” he said.

Other tools include possible changes to shipping lanes, increased aerial surveillance, and use of remote-controlled acoustic equipment and developing whale-friendly fishing gear.

In the United States, the National Oceanic and Atmospheric Administration released its five-year review of the North Atlantic right whale population earlier this month. Besides recommending the species remain classified as “endangered,” the plan made several other specific recommendations for future action:

  • Designating Diane Borggaard, a biologist with 20 years of experience in species recovery, as the right whale recovery coordinator for the Greater Atlantic Region;
  • Convening a new Greater Atlantic Region North Atlantic Right Whale Recovery Team – a group of experts in whale research and management that will coordinate closely with the Southeast Region’s Implementation Team. NOAA said it plans to develop the team’s mission and begin recruiting members soon.
  • Collaborating with the U.S./Canadian transboundary working group to reduce ship strikes and fishing-gear entanglements. This process has included several meetings between NOAA and Fisheries and Oceans Canada to discuss gear modifications, gear markings, and ship-speed regulations.
  • Convening a bilateral work group with Canada to focus on addressing the science and management gaps that are impeding the recovery of North Atlantic right whales in U.S. and Canadian waters. The group’s first meeting took place on Monday, 11 September, 2017.

In addition, NOAA is pursuing more research on understanding how chronic, nonlethal entanglements may be affecting overall and reproductive health of the right whale population. It’s also studying the effects of changes in environmental conditions and prey availability, as well as requesting funding to perform acoustic, aerial, and shipboard surveys of right whales “that can be used to understand right whale presence in near real time.”

NOAA also said it is reviewing the effects of commercial fishing operations on right whales.

Earlier this summer, the Marine Stewardship Council announced Eastern Canada’s snow crab fishery had retained its certification for sustainable management, which it has held since 2012. However, the assessment of the fishery closed before any of this summer’s right whale deaths had been discovered.

Amy Knowlton, a researcher at the New England Aquarium in Boston, Massachusetts, told the CBC that ropes used to catch lobster and crab, as well as for gillnetting, have become stronger and thicker in recent years.

"The ropes are too strong for the whales to successfully live among those ropes," she said. "So we're trying to change the rope that's out there or eliminate it altogether."

Researchers are working with fishermen to develop and test a lighter whale-release rope, and exploring the possibility of using other types of technology to retrieve gear off the ocean floor, rather than ropes.

"We're trying to get an understanding of what the fishermen need to effectively fish and we now have a better understanding of what the whales need," she told the CBC. "I think if nothing changes, and soon, we could see the extinction of this species within several decades. I think we can reverse this trend but it's going to take a lot of collaboration."


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