Only 73 southern resident orcas exist in the wild, scientists just discovered that 3 of them are pregnant
ON a routine research trip, two marine biologists were struck by what they saw in the waters of the Pacific Northwest: three endangered orcas with bulges indicating that they are pregnant.
The discovery was delightful – there are only 73 southern resident killer whales in the wild, and time is running out to save the species from extinction. Orcas, also called killer whales, give birth to one baby at a time, every three to 10 years.
“Killer whales reproduce very slowly, so it’s hard to recover the population,” said John Durban, who made the discovery with his wife and research partner, Holly Fearnbach. “Deaths are outpacing births.”
All three pregnancies appear to be in their late stages, they said.
“Their shape change was really prominent, so it was fairly obvious,” said Durban, 45, a senior scientist at Southhall Environmental Associates Inc. “When they’re pregnant, they get a bulge below the rib cage, just like people.”
The pregnancies are notable because the total southern resident killer whale population is at its lowest point since the 1970s. Just 44 orcas have been born since 1998, and within the same time frame, 81 have died or disappeared. One captured the world’s attention in 2018 when she gave birth, then carried her dead calf for 17 days and more than 1,000 miles.
When Durban and Fearnbach made the discovery on Sept. 6, they were in the middle of the Salish Sea – between Washington state, where they live, and British Columbia – on a 24-foot-long bright orange research boat. Southern resident killer whales, one of several orca populations that live along the West Coast of the United States and Canada and the only one that is designated as endangered under the Endangered Species Act, spend much of their time in those waters.
For the past 14 years, Durban and Fearnbach have been using aerial drone technology to closely monitor the southern resident killer whale population. Although they collect data as a duo yearround, they photograph the orcas each September, which is when the marine mammals spend the most time foraging for salmon in the area.
On average, orcas have a 17month gestation period, though there is no clear timeline for how far along the three presumably pregnant whales are.
The southern resident killer whale population consists of three distinct social pods: J, K and L. They are social groups of whales that share a maternal ancestor. For tracking purposes, each animal is identified by a pod letter and number. The three that are pregnant are part of the J Pod: J36, J37 and J19.
The prospect of a small baby boom is critical, scientists say, because it could help bring the species back from the brink of extinction.
“It’s positive news for sure. We need births to start outstripping deaths,” Durban said. “We can’t have a recovery without calves, so it’s really exciting.”
Still, he and Fearnbach remain cautiously optimistic, considering that killer whales have a high rate of miscarriage and infant mortality.
“Unfortunately, most pregnancies aren’t successful,” said Fearnbach, 45, who is the marine mammal research director at the nonprofit SR³ SeaLife Response, Rehabilitation, and Research.
Last year, there were several failed pregnancies, and over the past decade, there’s been a relatively high rate of reproductive failure among southern resident killer whales.
The species has been listed as endangered under the Endangered Species Act since 2005, and according to the Washington Department of Fish and Wildlife, the population continues to face three central challenges that threaten its chances of long-term survival: food shortages, chemical pollution, and vessel noise and disturbances.
Female whales are especially affected by boaters, as they tend to stop foraging for food whenever a vessel nears. Scientists are even more concerned about the issue, since it could have dire consequences for the three pregnant - and hopefully soonto-be nursing - mothers who will need to forage for additional food to support their calves.
Dawn Noren, a biologist at the National Oceanic and Atmospheric Administration, explained that female orcas require 25 per cent more sustenance during pregnancy, and nearly double after birth. “Very early on in the lactation period, these females will need substantially more food,” she said. “It’s very important.”
In light of the pregnancy announcement, officials are urging boaters to strictly follow the Be Whale Wise regulations, which say all humans and vessels must stay at least 100 yards away from marine mammals.
“We’ve got many people looking at the science to understand where we can continue to improve the odds for this population,” said Kelly Susewind, director of the Washington Department of Fish and Wildlife, in a news release.
“Now that we’ve learned of multiple pregnancies among the southern residents and the impact that boats can have on new mothers, we really need everyone to follow Be Whale Wise regulations in support of these endangered whales’ survival.”
The federal government adopted a plan Sept. 15 to curb commercial and recreational salmon fishing along the West Coast whenever the Chinook salmon population gets notably low, since southern resident killer whales depend on the fish as their primary food source.
The new restrictions include reducing fishing quotas in some regions, delaying the start of the ocean commercial troll fishery for hundreds of miles between Cape Falcon in Oregon and Monterey Bay in California, and shutting down other areas to fishing for most of the year.
“These are really important steps toward helping these females have successful pregnancies,” Noren said.
Like other scientists, she too is cautiously optimistic about the outcome of the pregnancies.
“They have a long road ahead,” Noren said.
“I’ll be really excited when I actually see a live calf swimming next to the mom.”
She is more hopeful than in previous cases, she said, since all three pregnant whales are not first-time mothers, which comes with a higher risk of complications.
“We expect to see some success,” Durban said.
“It’s a small and endangered population, so every calf counts.” — The Washington Post