The Southern Resident orca known as Tahlequah sparked global sympathy in 2018 when she pushed the body of her dead calf for more than two weeks in the waters off the southern coast of British Columbia.
Some scientists and animal rights activists called the scene a display of public grief.
However, the impact of this loss has reached beyond Tahlequah. It is a major blow to the entire Southern Resident orca population, which numbers just 74 individuals.
Recent research suggests a baseline rate of population loss of about 1% per year – based on modeling and 40 years of observations – putting the whales on track for a “period of accelerated decline that portends extinction.” Even that rate of loss is “optimistic,” the research says.
The study underscores the urgency of calls by a coalition of environmental groups for the Canadian government to reverse its decision not to issue an emergency protection order for the whales, in the face of what could otherwise be an inexorable decline.
The ocean’s top predators are listed as endangered under Canadian and U.S. endangered species laws, which are intended to trigger protections. But the measures have shown no signs of recovery for the whales, said the coalition, which includes the David Suzuki Foundation and the Raincoast Conservation Foundation, among others.
Misty MacDuffee, a conservation biologist with Raincoast, said the whales’ long potential lifespans could obscure their path to extinction. Parks Canada says one whale known as Granny was estimated to be 105 years old when she died, though that age has been disputed.
“We must always remember that these are long-lived animals and the population can disappear over decades simply because these animals are still alive,” Mr.me MacDuffee, co-author of the recent study.
She explained that the research published in the journal Communications Earth & Environment in April shows “there is no possibility of recovery” for the Southern Resident orcas under current habitat conditions.
The study notes that in a population of 75 whales, “a single birth or death represents an annual population growth or decline of 1.4%, highlighting the value of each individual in preventing a population from extinction.”
“It’s so serious for these whales. If we had acted ten years ago […] “We might not be in this situation. We have done very little,” Mr.me MacDuffee.
“The government is making decisions to say, ‘Well, economics and other goals outweigh the recovery of these whales.'”
“Imminent threats” to their survival
As threats mount in the Salish Sea, the busy shipping lane off British Columbia’s southern coast where southern resident orcas feed on king salmon, scientists say the whales’ survival is hanging by a thread.
Southern Resident orcas have become a symbol of the region’s beauty and biodiversity and are of particular importance to indigenous peoples.
In Washington state, the Lummi Nation’s name for orcas, “qwe lhol mechen,” means “family members beneath the waves.”
They are also captivatingly complex.
Mme MacDuffee highlighted Tahlequah’s behavior as a kind of public mourning for her dead baby.
“She did it publicly. She went around the most prominent waters. She didn’t go out, you know, off Swiftsure Bank,” Mr.me MacDuffee, referring to a site at the Pacific end of the Strait of Juan de Fuca. “She stayed here and went through Haro Strait, the Gulf Islands, the Strait of Georgia, the most prominent waters she could find herself in.”
This complexity has not always been respected: the Southern Resident orcas were decimated in the 1960s and 1970s by live captures for aquariums, and they have not been able to recover since. They do not breed with other orcas.
In 2018, Canadian officials determined that the southern residents faced “imminent threats” to their survival and recovery. These included the availability of king salmon, ship strikes, and disruptions from noise and environmental contaminants.
But Ottawa declined to issue an emergency order at the time, choosing instead to update the pre-existing recovery strategy and highlight measures and commitments already in place, including seasonal fisheries closures, work to rebuild king salmon stocks and tools to alert ships to the presence of whales.
Mme MacDuffee argued that conditions have only gotten worse for southern residents since then, with no signs of recovery despite government efforts and promises.
New projects that cause concern
Conservation groups say existing measures aren’t working, especially as more tankers have begun carrying petroleum products from the expanded Trans Mountain pipeline. Last year, Ottawa also approved plans for a new marine container terminal near the mouth of the Fraser River.
The coalition’s demands include a ban on further increases in shipping traffic from new federally approved industrial projects in the Salish Sea until Ottawa provides a comprehensive plan to manage the cumulative effects of underwater disturbances.
The groups also want the federal government to increase the minimum distance vessel operators must stay away from whales to 1,000 metres, from 400 metres; and to adopt “meaningful” underwater noise reduction targets.
An email from Fisheries and Oceans Canada said the department was “reviewing the petition to determine the way forward” while highlighting its existing efforts.
The federal government says it is working on measures to address underwater noise and the risk of ship strikes, to update federal requirements for responding to marine oil spills, and to help Indigenous groups monitor the cumulative effects of human activity.