Researchers Studying Endangered Pacific Northwest Orcas Feel Their Absence

The southern resident orcas have been late to return to their home waters in Washington's Salish Sea. Researchers grapple with why, and what the whales' absence reveals about the state of the ecosystem.

The text at 6:45am couldn’t have come early enough for killer whale researcher Deborah Giles. It had been about two months since the critically endangered southern resident orcas that she and others so closely track had been absent from their home waters in the Salish Sea and worries were mounting.

The black-and-white orcas, the friend texted on July 5, were finally back and were intermingling and socializing on the west side of Washington state’s San Juan Island in the familiar “west side shuffle.”

Orca whales make their way along the west side of San Juan Island in what’s known as the “west side shuffle.” (Video Courtesy: Orca Behavior Institute)

Giles, who is part of a research team at the University of Washington’s Center for Conservation Biology that uses dogs to sniff out whale poop on the water, immediately called two colleagues. “How soon can you be on the boat?” she asked them. 

By 8:15am, Giles, her colleagues and her 4-year-old mixed-breed named Eba, a scat-detection dog with Conservation Canines, were out on the water with the whales in search of the floating poop they leave behind.

With Eba at the front of the boat signaling where to go by her behavior, the researchers followed the orcas from a distance and scooped up fecal samples on the surface of the water. They’ll analyze stress, reproductive and nutrition hormones, and toxic chemicals in those samples to help answer questions about the health of the small isolated population of orcas that are in rapid decline.

The pods—identified by the letters J, K and L—typically spend May through September in the Salish Sea, concentrating off the southern end of Vancouver Island and San Juan Islands as well as Puget Sound, their traditional core summer habitat, feeding on Fraser River chinook salmon, whose runs have dwindled in recent years.

The orcas have been notably absent from their summer core habitat, raising concerns about whether the fish-eating whales are finding enough food and where they might be. It was the first time they didn’t appear at all in June in the inland waters of the Pacific Northwest, said Monika Wieland Shields, co-founder of the Orca Behavior Institute.

Their return in early July was brief.

The orcas did a quick sprint up to the mouth of the Fraser River in British Columbia, and then they left the Salish Sea the next day. The orcas were last seen on July 8, when Canadian researchers sighted them near the west entrance of the Strait of Juan de Fuca. 

“There’s just not enough food to keep them here,” said Giles, who is also science and research director for the nonprofit Wild Orca. “The fish that they would have been after in the past are not here, and that’s a bad thing.”

Unlike killer whales that are thriving elsewhere, this distinct population of southern resident killer whales is at a high risk of extinction. Listed as endangered in the U.S. and Canada more than a decade ago, they face three complex, interrelated threats: lack of their preferred diet of chinook salmon (many populations of which are endangered or threatened due to habitat loss, dams and fishing); exposure to toxic contaminants through the fish they eat and the environment that may pose a health risk; and disturbance from vessels that can disrupt their ability to communicate with each other and forage.

The orcas are unique because they eat fish, mostly chinook salmon, rather than marine mammals. (By contrast, the numbers of transient whales, also called West Coast Bigg’s killer whales, are growing in the Pacific Northwest as they feast on robust populations of sea lions and other pinnipeds). The southern resident orcas are highly social and live in distinct matrilineal family groups led by the oldest female. Scientists identify the whales by the unique markings on their fins, and each are photographed and given a name.

Their numbers have fluctuated over the years, dropping to a low of 71 in the 1970s when dozens were captured for marine parks and aquariums across the U.S. More recently, female orcas have had pregnancy troubles and the population is now at just 75 orcas as of January, the lowest in more than three decades. (During the July 5 sighting, researchers with the Center for Whale Research confirmed the birth of a female calf, J56).

The orcas have come to symbolize the Pacific Northwest, and many advocates warn that their decline underscores the state of the ecosystem.

“The whales are having to work a lot harder and go farther to find adequate food at this time of year,” said Ken Balcomb, founder of the Center for Whale Research on San Juan Island, which keeps the official census of the orcas for the U.S. government. “The only solution to saving the whales is to restore the ecosystem’s rivers and natural salmon runs to strategically provide for year-round (southern resident killer whale) prey resources.”

Fraser River chinook salmon have been important to the orcas during the spring and summer, though the whales rely on a number of West Coast chinook runs from British Columbia to northern California throughout the year. But Fraser River runs have been declining for years due to a host of factors including habitat loss, harvest and changing climate conditions. The Canadian government this year put new restrictions to limit the catching of chinook salmon to protect the whales. 

“The Fraser River isn’t providing for them in the same way it used to,” said Shields. “The fear is that they’re not finding food anywhere. The hope is that they found a better source of food somewhere else.”

Three whales make their way across the Salish Sea with the islands in the background

A photo of orcas captured by the Orca Behavior Institute in 2016. Researchers fear that the Fraser River isn’t providing enough chinook salmon for the whales the way it once did. (Photo Credit: Monika Wieland Shields)

The Salish Sea is also biologically and culturally important for the whales, a place where the three pods would come together in the summer for “greeting ceremonies,” she noted. “Historically, they were here for a reason. It’s a huge concern.”

Killer whales, the largest members of the dolphin family, typically make “investigative runs” through an area to find what prey is available, added Brad Hanson, a wildlife biologist with NOAA’s Northwest Fisheries Science Center in Seattle who has studied the orcas for years. “If it’s good, they’ll stay. And if it’s not, they’ll take off.”

“What’s strange is that we haven’t had many of these investigative forays that they would typically do in inland waters,” Hanson added. “They typically come once every week or 10 days, but they’ve only been in a couple times. The flip side is that perhaps they’re finding sufficient prey on the outer coast.”

Balcomb said the orcas have been spending time out on the Pacific Northwest coast, along the west coast of Vancouver Island, and are likely eating salmon coming from the Gulf of Alaska and bound for rivers.

One concern is that on the outer coast the orcas have to compete more directly with other whales for that salmon, Hanson noted.

When the orcas aren’t in the Salish Sea, they spend time, typically winter months, in coastal waters from southeast Alaska to Central California. And it’s much harder to track them out on the outer coast.

Hanson said he’s currently working on a grant proposal so that he can get out in coastal waters next spring to better track them.

Meanwhile, he and other researchers are also waiting this summer until the whales return to the Salish Sea so they can continue their research about the threats the orcas face.

During the two days the orcas returned to the Salish Sea, Giles and the research team collected four fecal samples that have not yet been analyzed. Last year, the UW team collected 45 fecal samples.

In a study published in 2017, researchers analyzed hormones from fecal samples collected and found that more than two-thirds of orca pregnancies failed over a seven-year period from 2007 to 2014. They linked those problems to nutritional stress brought on by a low supply of chinook salmon.

The fecal samples are also helping to answer other questions.

“We know anecdotally that when the whales come back in their fecal samples tend to be fattier and larger compared to when they’ve spent time in inland waters,” Giles said. They’re hoping to determine the quality and quantity of salmon that the whales are eating based on the scat they poop out a day later, she said.

 But they can’t continue their studies until the whales return.

Giles said it was amazing to see the orcas looking healthy when they returned to their home waters in early July, but it’s bittersweet because they didn’t stick around. “This is their summer core critical habitat. It begs the question of what on Earth is happening?”

To learn how to sea kayak around whales, read the Journal’s previous coverage, How to See Whales by Kayak (Responsibly).