North Atlantic right whales should live well past 100 years, but threats to the endangered species, including from commercial crab and lobster fishing, have cut their lifespan to a fraction of that, a recent study suggests.
Published in the journal Science Advances, the study focused on southern right whales, which aren’t endangered and can live up to 130 years. However, as southern and northern right whales are closely related, lead author Greg Breed said the study “confirmed the sad state of affairs” of the whales that travel up to Canada to feed.
“I wasn’t, unfortunately, at all surprised, because we’ve known this species has been gravely endangered for some time,” Breed, a biology professor at the University of Alaska Fairbanks, said in a recent interview.
On average, North Atlantic right whales live 22 years, a reduced lifespan Breed attributes to ship strikes, entanglements with fishing gear, and climate change.
The historical whale hunt, he added, has compounded the North Atlantic right whale’s troubles, leaving the population with almost no older whales — and little inherited wisdom for the younger generation, such as how to navigate the ocean to find food as the climate changes.
“This is a big deal. This is a really big problem.”
North Atlantic right whales were subject to “Yankee whaling,” which ended around 1910, he said. Given the animals’ slow rate of reproduction, the small number of whales that weren’t hunted were mostly younger. Females begin to give birth when they are 10 to 12 years old, and reproduce once every three to five years.
“They produce calves quite infrequently…. And North Atlantic right whales are just being hammered by all these man-made threats, particularly entanglement with fishing gear.”
The North Atlantic right whale is an endangered species with about 370 animals left in the wild. The main threats they face are entanglements in lobster and crab fishing gear, and strikes by commercial vessels, both of which can be fatal.
Breed said the last time any North Atlantic right whale reached its natural lifespan was likely around 1700 or 1800, when whaling was in full force but had not yet decimated the population.
“But it wasn’t long after that the populations of the North Atlantic right whales were almost completely eliminated through whaling, and all the old individuals would have gone at that time too,” he said.
“Because in order to survive to be 150, say in 1800 or 1850, you would have had to have survived 70 years of really intense whaling. And that would have just been nearly impossible.”
North Atlantic right whales are struggling to avoid extinction in a changing ocean but with one calf already spotted at the beginning of the calving season, this protection group says there’s a reason to be optimistic.
A long lifespan, the study said, allows animals to delay the age they start to reproduce, or to have babies when conditions are favourable.
North Atlantic right whale “life history traits” — such as the age they start to give birth — are consistent with much longer lifespans, the study said, more evidence that the current average of 22 years is atypical and due to high mortality.
That this longevity has not been recognized has “profound” implications toward understanding basic biology and conservation of whales, the study said.
It’s going to be hard to right the wrongs done to this whale species because of the economic pressures of lobster and crab fishing, and the changes in climate, Breed said.
Scott Kraus, a research scientist emeritus from New England Aquarium, said Breed’s research is another way of reporting that the North Atlantic right whale is in serious trouble.
“What it means is that conservation efforts over the last 30 years have not succeeded and they’re not on track to keep the right whale from going extinct,” he said. “It’s basically a four-alarm fire.”
The way forward
Animals such as the North Atlantic right whale fertilize the ocean, Kraus said. Their feces nourish the ocean, creating the productivity that supports major fisheries, he added.
Conservation efforts are usually framed as a conflict between economic interests and welfare of wildlife, he said. But the correct framing is to present the situation as a battle between short-term and long-term benefits.
To achieve those long-term economic benefits that come with having species such as North Atlantic right whales, he said, fishing and shipping have to be regulated, and more action taken toward climate control.
“We’re so concerned with annual reports and stockholder returns from corporations that we don’t pay attention to the long-term consequences,” he said. “It’s the way you do the math.”
