Experts aim to solve whale death mystery
EARLY FINDINGS POINT TO BLUNT TRAUMA IN TWO OF THE SIX MAMMALS DISCOVERED IN ‘DIE-OFF’
Ateam of pathologists and marine-mammal experts converged on a remote stretch of redsoiled beach in northwest Prince Edward Island last week to try to unravel a mystery: what caused the “unprecedented die-off” of six whales — members of an endangered species — in the Gulf of St. Lawrence?
After three of the North Atlantic right whales were carefully towed to shore, experts — fighting through the rancid smell of rotting carcasses — sliced and peeled away thick layers of blubber and muscle to search for clues.
Preliminary findings of the necropsies released late Monday indicate that two of the whales may have died from blunt trauma — likely from colliding with a vessel — while a third appeared to have died after becoming entangled in fishing gear, though the scientists stressed that further testing was required to see if there may have been underlying causes.
Marine conservationists said they hoped the die-off would hasten implementation of a federal action plan drafted last year to try to protect the species, whose numbers have dwindled to about 500 along the East Coast of North America.
“For this particular species, there are so few of them left; we lost over one per cent of the entire population left on the planet,” said Tonya Wimmer, director of the Marine Animal Response Society. “For this critically endangered species, every individual counts.”
Known to travel as far south as the Florida coast, North Atlantic right whales can grow up to 18 metres in length — longer than a school bus — and weigh up to 80 tons. Unlike their more streamlined brethren, right whales are rotund and bulky with heads that can take up one-third of the length of their bodies. These gentle beasts typically feed on tiny crustaceans called copepods.
By the early 1900s, the population along the eastern seaboard was decimated due to whaling.
Whalers viewed them as the “right” species to hunt because they moved slowly and remained afloat when killed.
Today, vessel strikes, entanglement in fishing gear and underwater noise have been identified as the most serious threats to right whales. In 1980, the Committee on the Status of Endangered Wildlife in Canada designated North Atlantic right whales as endangered.
Six right whale carcasses were spotted floating in the southern Gulf of St. Lawrence between June 6 and June 23.
The three that were brought to shore for dissection last week — two males and one female — were in advanced states of decomposition.
Having sat for days in the sun, their thick layers of blubber basically turned their insides into large ovens. The Marine Animal Response Society, Canadian Wildlife Health Cooperative and federal Department of Fisheries and Oceans Canada quickly mobilized a team of specialists with some people coming from as far as B.C. and North Carolina.
“When these things happen, we know we have to leave everything else behind,” said lead pathologist Pierre-Yves Daoust, a professor at the Atlantic Veterinary College at the University of Prince Edward Island.
“This cannot wait. Each day, the carcasses decompose more. The decision was easy for all of us involved.”
Dressed in disposable coveralls, team members used butcher knives and special flensing knives to cut through the whales and then used the bucket of an excavator to peel away the tough, greasy layers of blubber and muscle.
Many of the internal organs — kidneys, lungs and intestines — were unrecognizable from decomposition. But there was indication that two of the whales had suffered severe blood loss from blunt trauma, Daoust said. The third whale had become entangled in fishing rope.
They collected what bodily fluids they could and sent them off to labs to determine if any underlying problems — like infectious disease or toxic algae blooms — may have caused the whales to become more susceptible to harm. Results won’t be available for several more weeks.
A spokesman for Fisheries and Oceans Canada said Tuesday the department needed time to review the preliminary findings before commenting further.
Last summer, the department released a draft action plan aimed at protecting North Atlantic right whales.
Among other things, it recommended a study of the locations and types of fishing activities most likely to cause entanglement or entrapment to help guide mitigation measures.
Almost one year later, the government has not finalized the plan. Wimmer says the government needs to move more quickly.
She added that the reconfiguration of shipping lanes in the Bay of Fundy years ago helped to significantly reduce lethal vessel strikes.
The same work, however, has not been done in the Gulf of St. Lawrence.
“It’s a bit slow moving process ... Ideally, prevention is the key here,” she said.
“We can control the human activities. Let’s do it, let’s find a way to do it.”