New Brunswick

Dead right whales show evidence of collision with vessels, wildlife pathologist says

Scientists expect to have formal report on whales found dead in gulf in about a month

Elizabeth Fraser - CBC News

July 04, 2017

The body of a right whale was brought to land in preparation for a necropsy. (Nicole Williams/CBC)

Two of the right whales found dead in the Gulf of St. Lawrence bore signs of trauma suggesting they collided with ships, says the wildlife pathologist leading the investigation into why six right whales turned up dead in the gulf in June.

"The negative interactions with vessels can be an issue in the Gulf of St. Lawrence," Dr. Pierre-Yves Daoust of the Atlantic Veterinary College in Charlottetown said Tuesday on Information Morning Fredericton.

ADVERTISEMENT

The discovery of the six endangered North Atlantic right whales floating dead in the Gulf of St. Lawrence brought more than 40 people from various organizations to the shores of western P.E.I. to study three of the carcasses. 

Preliminary results from the three necropsies done in Norway, P.E.I., last week show evidence of blunt trauma in two of the whales and an "entanglement" in another, Daoust said.

He wants the Canadian Coast Guard and industry to discuss how to preventing these "negative interactions," along the East Coast of Canada and the U.S.

"I would welcome the start of a discussion about this kind of potential interaction between an endangered species like the right whale, and the fishing industry and the shipping industry."

With only 525 right whales remaining, the recent "unprecedented die-off" represents more than one per cent of the population, the Marine Animal Response Society said in a news release Monday.

Vessels moving at high speed

Daoust suggested a reduction in vessel speed could reduce the number of collisions with whales.

Vessels in the Gulf of St. Lawrence tend to move at a high speed, which can potentially harm right whales that come into the gulf to feed.

Right whales actively feed, diving into deep waters for about 20 minutes, he said. Often, they return to the surface just where their dives started.

'Now is the time to consider how best to make sure the Gulf of St. Lawrence is a suitable habitat for them.' - Dr. Pierre-Yves Daoust

"It's quite possible that a large vessel that was many nautical miles away when they started diving, as they surfaced, this vessel may be much closer," he said.

"It may be very difficult for those whales to move fast enough out of the path of those vessels to avoid the strike."

A number of possibilities

Because of the right whales' decomposition, there are possible causes of death that cannot be confirmed or ruled out, Daoust said. 

There's also a chance the Bay of Fundy may not be the good environment it once was for the whales.

"In the winter they were further south," he said. "In the summer they came into the Bay of Fundy to feed very extensively, and there may have been a decrease in the amount of [plankton] in the Bay of Fundy."

These theories bring bigger questions into play about the ecology of the ocean that need to be addressed, Daoust said.

Toxic bloom possible

Experts are also not ruling out factors such as bio toxins produced by algae bloom as the cause of death.

"Now is the time to consider how best to make sure the Gulf of St. Lawrence is a suitable habitat for them," he said.

Scientists who took part in the necropsies have left the Island with samples and expect to have a formal report in about a month.

With files from Information Morning Fredericton, Terrence McEachern
Start the day smarter
Get the CBC News Morning Brief, the essential news you need delivered to your inbox