The two P.E.I. pathologists working to determine what killed six of the 13 right whales found dead so far this summer say it will still be weeks before their final report is complete.

Atlantic Veterinary College pathologists Pierre-Yves Daoust and Laura Bourque said trying to determine what killed the endangered whales has been their main focus since late June, when they led the necropsies of three of the six right whales discovered dead at the time. 

But they said there's still a lot of writing, research, and discussions with other groups that needs to take place. 

'Not straightforward'

"This is not straightforward, and we don't want to rush into anything," Bourque said. "If we get it wrong, it affects many communities and peoples around the Maritimes." 

"If we say something that isn't right, and all of a sudden we have to close down the fisheries for whatever reason, that would be awful. We want to make sure that what we see is correct," she added.

"If we get it wrong, it affects many communities and peoples around the Maritimes."
- Laura Bourque, AVC pathologist

The federal Department of Fisheries and Oceans has already closed or restricted some crab fisheries in the Gulf of St. Lawrence, where the majority of the dead whales were found. It's also issued notices to fishing vessels to slow down. 

That's after preliminary necropsy results revealed some of the dead whales suffered blunt trauma and bore signs of chronic entanglement, likely from fishing gear. 

Biotoxins, chronic disease could be ruled out

But Bourque said experts still can't say definitively what killed any of the whales.

"We know entanglement is an issue right now, and we're wondering about boat strikes. But it's going to be a while before we can say anything definitive," she said. 

"In our report we can say 'yes or no there was evidence of trauma.' But then we need to pair that with were there even ships in the area at that time?"

Bourque said she and Daoust, along with pathologists from the University of Montreal, who led two of the necropsies in Quebec, are still waiting on the results from diagnostic testing of tissue samples from the whales.

Laura Bourque

Bourque says she and Daoust are still waiting on the results from diagnostic testing of tissue samples from the whales. (Steve Bruce/CBC)

She said those results may help them rule out biotoxins or chronic disease as possible causes of death. 

Daoust added that even after that information is known, they'll still need to complete and compile six individual necropsy reports. 

"Then we need to provide a document that will summarize all those findings on those six whales to see if there are common factors among the six of them," he said.

'Unprecedented event'

Daoust said the final report will also include research from other scientists and agencies on the whales patterns, as well as shipping and fishing activities in the Gulf.

"Because it is an unprecedented event, this is something that will be important years and years down the road," he said.

"People will need to go back to this report and have all the information available … so, it is important that we produce a report that tries to answer all aspects of this mortality event."

Whale report

Bourque says their work isn't straightforward. (Steve Bruce/CBC)

Daoust wouldn't put a timeline on exactly when the report will be complete. 

Whenever it is finished, he said it will be passed on to Fisheries and Oceans Canada to help with its efforts to prevent future die-offs.