One of the seven veterinarians from l'Université de Montreal performing a necropsy on the whale's carcass on Wednesday told CTV News the mammal had no obvious lacerations or broken bones, but that some discoloration and internal hemorrhaging leads them to suspect a boat strike may have taken it down.
"The fact that the animal seems to be in good body condition to start with and was found dead suddenly, that tells us that there’s actually a suspicion of a trauma by a boat," said veterinarian Dr. Stephane Lair. "We’re starting to see some areas that are a little more reddish than they should be... Having said that, it’s too early in the autopsy to be able to conclude.”
The whale's lifeless body was discovered drifting down the St. Lawrence River past Varennes on Tuesday morning, and was lifted onto land during the evening at Sainte-Anne-de-Sorel, just over an hour’s drive northeast of Montreal.
The fact that no boats have reported hitting the whale doesn't rule out the possibility of a boat strike, Lair said.
“The boat could hit a whale and just not notice it, and it could happen at night too."
The necropsy – which is like an autopsy, but performed on animals – aims to answer many of the questions about what happened to the 10-metre whale who captivated Montrealers for the week and a half it was in town.
Based on a preliminary analysis of the creature's body, which showed no immediate signs of poor health, the team of veterinarians seem to think she was doing well.
"She was really strong, and she didn’t seem to be sick," Lair said. "Having said that, often, wild animals, when they’re sick, they’re going to hide their symptoms… So the fact that she looked healthy is not necessarily the proof that she was healthy.”
She might have been unable to navigate well if she was sick, which could explain her presence in Montreal, according to Marie-Ève Muller of the Quebec Marine Mammal Emergency Response Network. She might have also ventured away from her home in Tadoussac in search of prey.
In the past, there have been sightings of minke whales and belugas in Montreal’s harbour. But all those stories have turned out differently from each other – sometimes the whale “turns around and goes back to its habitat,” Muller said. Sometimes they die.
Outwardly, the whale didn’t seem to be getting thinner during the time it spent in Montreal, Muller said. The necropsy will also look at this mystery, to try to determine what exactly it was eating in Montreal’s freshwater.
A humpback usually eats krill or small fish, but “in Montreal, of course, it's not the same species you’d find in the [St. Lawrence] Estuary or the Gulf,” said Muller.
Scientists may end up finding that in the end, the whale was healthy overall, with no clear reason to travel so far down the river. It’s possible it simply had an adventurous adolescent mindset that led it to “try and discover new habitats a bit,” she said.
The team of veterinarians will spend the next few hours having "a closer look into the muscles and the skeleton" of the whale, Lair said. They will then finish up their work by looking at its internal organs and sending some samples to labs for further analysis.
The team expects to have a post mortem/necropsy report in about a month or two, but notes that those aren't always conclusive.
“We’re not successful in determining cause of death in all cases," Lair said.
He also said that boat strikes are a big issue for whales around the world. When it comes to humpbacks, though, an increase in population over the past few decades means they aren't at risk of extinction, as sad as this death is.
"If you take other species like the right whale... Boat strikes are probably the number one cause of mortality in that species, and the right whale is close to extinction right now," Lair said.