Image copyright GIZMODO Image caption The COVID-19 creatures have mutations and genes that reduce their risk of infection
At least 815 new cases of the invasive orca killer whale known as an “old whale” have been reported in Quebec since February, three new cases reported last week.
The creatures have developed mutations in their genes that make them less susceptible to the virus that causes respiratory distress.
Up to 14 adults have now been confirmed dead.
This has prompted fears of a “crisis” in the population.
Some experts, like the Conservation and Resource Management Department of the Atlantic province, have called for more whales to be released.
But others, like Conservation and Marine Service National Marine Mammal Service, have questioned the need to breed now, as the adult whale population is around 750.
COVID-19 stands for the endangered ORC (Orca River Killer) female, which was sent to be studied after being shot and killed at SeaWorld in 2010.
Her “old whale” relatives have not been given a code by researchers in years.
“It is impossible to begin the breeding programme in this context,” said Alain Therrien, director of the Marine Mammal Service National Marine Mammal Service.
“With these ageing whales, there will be a potential disease outbreak in the future,” he told reporters in Quebec last week.
“We have to wait,” he added.
Those words led to a debate on TV and radio.
An editorial in the Canadian daily Le Devoir contrasted the isolated elderly whales with a sudden spike in the number of sightings of baby orcas in 2017 – four were born.
“These newborns will grow up in a different context in future,” Dr Leanne Grey-Levine, a professor of marine and environmental biology at the University of British Columbia, explained in the piece.
“They may not be able to find the old whales easily in order to learn how to survive. And as they will not go far distances, they may never be able to transfer their knowledge of how to handle their illness or how to defend themselves, rather than simply replace the bodies of old whales. There will be no genetic link that spreads survival in such a cold, barren region.”
The north-eastern Canadian waters have been unusually abundant this year, with more than 4,000 southern resident killer whales previously identified.
Dead orca whales are piling up – and are usually either washed up on shore or trapped in nets as they swim into the ocean.
Although scientists don’t think they can pinpoint a particular cause of death, there have been reports of increased flies, bacteria, and moss, dark seaweed and moss that bio-mechanically obstruct the sense of smell.
Officials at the Fundacion Science Meditat in Halifax have observed a “steep rise” in hydrates, leading them to wonder if those contaminants have affected an organ called the larynx that is used to expel water from the lungs.
They have also started to suspect “mutation” and that the killer whales were infected with Mers virus.
Infection of the brain itself is more likely, said Dr Kerry Brown, a scientist at the Vancouver Aquarium’s marine mammal research unit, but Mers is not known for causing widespread outbreaks.
“It’s premature to suggest that this virus is the reason for their deaths,” he told CTV News.
“In fact, there’s no evidence from this outbreak that they’ve been infected with Mers virus.”
He told the BBC it is possible the deaths of the adult whales could be a “blowback effect” after an especially busy January, with an even busier March, which may be uncharacteristic.