This text is taken from the “Courrier de la planete” of May 31, 2022. To subscribe, click here.
The analysis of the carcass of the minke whale found dead in the Contrecœur sector last Thursday did not make it possible to determine the cause of death of this whale, the second to have arrived in the Montreal region at the beginning of May.
After being spotted last Thursday in the Contrecœur sector, the minke whale was pulled towards the shore, before being transported by truck to the Faculty of Veterinary Medicine of the University of Montreal, in Saint-Hyacinthe.
The team of Dr. Stéphane Lair, who carried out the necropsy (the analysis of the carcass) of the animal, was however not able to determine the exact cause of death of this young male of 3.8 meters, presumably between one and two years old.
“The necropsy did not reveal any significant cause of mortality and no sign of trauma was observed”, specifies the Group for Research and Education on Marine Mammals (GREMM). The young cetacean would therefore not have been hit by a ship after being observed for the last time on May 14 in the evening, between the islands of Sainte-Hélène and Notre-Dame.
“The absence of food in the stomach indicates that the animal would not have eaten recently”, therefore during its stay of a few days in the waters of the St. Lawrence River in the Montreal region.
Experts, however, found that the whale’s skin was covered in oomycetes, “an organism also observed on the Montreal humpback whale in 2020 which suggests an extended stay in fresh water”. What’s more, the state of preservation of the carcass suggested that the death of the animal went back “a few days, perhaps even up to a week if the carcass remained submerged”.
However, the work of Stéphane Lair’s team does not end there, since laboratory analyzes will take place on the various samples collected with a view to writing a final necropsy report.
Missing whale
As for the other minke whale, which spent a week in the Montreal region, it has not been seen since May 14. The Quebec Marine Mammal Emergency Network also asks the public to report any sightings of such an animal in the St. Lawrence River upstream from Île d’Orléans.
What explains the presence of these two whales in the Montreal region, more than 450 kilometers from their natural habitat, the St. Lawrence estuary? Impossible to know, according to the GREMM.
However, it should be remembered that calves of this species separate from their mother after barely a few months of breastfeeding. It therefore sometimes happens that juvenile individuals go astray. In 2016, then in 2017, cases of young minke whales found dead in the Lévis region were documented.
The species, which can reach nearly 10 meters as an adult, is frequently observed in the St. Lawrence. It is not threatened and is even subject to commercial hunting in Japan.
There has never been, in the entire history of Montreal, a documented case where two marine mammals were in the region at the same time. In the past, we have been able to see belugas in the vicinity of the metropolis, but also several seals.
In May 2020, a young humpback whale also attracted many curious people with its many spectacular jumps out of the water. She was eventually found dead in the St. Lawrence Seaway. The necropsy report concluded that she died as a result of a “sudden event”. Even if the trail of a collision with a ship in the St. Lawrence Seaway remains very plausible, the scientists who analyzed the case could not confirm this hypothesis.