Gray whales return: Researchers wonder why 'Sounders' seem healthier than others

Gray whales are making their yearly migration back to the Puget Sound for their annual feast.

Last year, the National Oceanic and Atmospheric Administration declared an “Unusual Mortality Event,” meaning there had been an unusually high number of gray whales who became stranded and died. Over 200 gray whales washed up during the whales’ commute between Mexico and Alaska in 2019, many underweight. In Washington alone, 34 were stranded in 2019. That’s a record of dead whales in Washington.

So far, just one has been stranded in Washington this year.

Another Unusual Mortality Event occurred in 1999-2000, but the recent event was far worse, said John Calambokidis, a research biologist at Cascadia Research. The lifespan of gray whales is unknown, according to NOAA, though one female was estimated to be around 80 years old at her death. Calambokidis said researchers are only beginning to get a sense of the lifespan of gray whales – from what’s known, most seem to live into their 50s and 60s.

Whales dying in Unusual Mortality Events often die prematurely and are typically underweight when their bodies are found. The peak time for whale deaths in Washington is from late March through June, Calambokidis said.

However, whales in this area seem to be doing better than whales in other areas, said Erin Gless, lead naturalist at Island Adventures Whale Watching.

Thousands of whales swim north every spring after breeding in Baja, Mexico, to where they feast during summers in Alaska. A group of around a dozen of these traveling whales makes a stop in the Puget Sound to snack on ghost shrimp on their way. These whales, nicknamed “Sounders,” return to Washington each year, and their return has served as a "Groundhog Day" of sorts, signaling the return of spring for decades. Gless operates gray whale tours in Everett and also works closely with research teams, like Calambokidis'.

At least six of these whales have returned for the season, according to Orca Network. Males #44 “Dubknuck,” #49 “Patch” and #53 “Little Patch” have been spotted in the Puget Sound, and a photograph of #56 was sent to the Cascadia Research Collective.

“Those four whales, 44, 49, 53, and 56 all made their first appearance in Puget Sound back in 1991,” Gless said. “It’s interesting to see they have all arrived at the same time this year, almost 30 years later.”

The other two whales have visited more recently, Calambokidis said.

The gray whales usually stick around in the Northern Puget Sound through May during their 10,000-mile roundtrip journey. Often, there are years between sightings of the same whale, as they don’t always travel the exact same route or stop in the same places.

What’s interesting, said Calambokidis, is that most baleen whales aren’t considered to form long-term social connections to one another, like killer whales often do.

“Many of these whales are the same individuals that have been coming back for this 30-year period,” Calambokidis said. “We see many of the same individuals together, in groups of two, three, four. They’re very interactive.”

Suction cup tags with small video cameras are used by Calambokidis’ research team to learn more about the whales. Videos show the whales often rubbing against one another. Though they may not form long-term social bonds, they still swim together over many years, he said.

The suction cup tagging was started in a study several years ago. Researchers knew gray whales were in the area to feed on ghost shrimp during high tide at the intertidal zone, Calambokidis said, but they weren’t sure if they were feeding in other areas. The tags helped researchers see what else they may be feeding on and what their activity looked like from underwater. The tags could also measure things like the depth the whales were swimming to.

This research found the “Sounders” were feeding almost exclusively on ghost shrimp during high tide, Calambokidis said. It’s the only time they can reach the area the shrimp live, and the pits created by gray whales searching for shrimp can be seen during low tide.

“This is a crucial time for the Sounders given the large number of gray whales that died last year,” said Calambokidis. “We hope to learn how this stop-over feeding area might be helping this group of whales survive.”

He wonders if the Sounders doing well is correlated to their stop in the Puget Sound to feed on these ghost shrimp, protecting them from a mortality event by giving them an extra nutritional boost from the two to three months they stop here. He also wonders if the Unusual Mortality Event will be a two-year ordeal like it was in 1999-2000. It’s still too early in the season to know, he said.

“One of the questions is how are gray whales doing overall,” Calambokidis said, “So far we’ve seen no drop off of those individuals. They appear to be in pretty good health.”

This spring, scientists like Calambokidis will be assessing whales’ health with the help of drones, breath-sampling, and more suction-cup tagging. Researchers coordinate with whale-watching boats and hope to get a full census of the whales this year to see which have returned. They also plan to get detailed measurements of the whales’ body conditions.

Dogs will also be used in the research of gray whales this season. Deborah Giles of Conservation Canines, a nonprofit organization that trains dogs for use in wildlife research, and her canine-companion, Eba, will be collecting fecal samples from whales to get a closer look at the Salish Sea ecosystem.

“Using trained dogs like Eba, we’ve been able to non-invasively collect whale scat to answer questions about killer whales, including the endangered Southern Residents,” Giles said.

Things like hormone levels, toxins, and microplastics can be measured using samples of whale feces the pup sniffs out.

Gray whales that are found in the eastern and western North Pacific are categorized as the “eastern population,” and migrate near the West Coast of the U.S. The “western population” migrates in eastern Asia.

Conservation measures were taken for the species in the 1930s and '40s after commercial whaling depleted the population nearly to extinction. The western population has only around 200 whales left and is listed as endangered. The eastern population that swims near our shores was no longer listed as endangered after populations recovered in 1994.

“The population is back to near-record levels,” Calambokidis said. It could be related to prey density in the Arctic, but it’s part of what researchers are still figuring out, he said. They’re still in the process of ruling out other contributing factors.

Gray whales are popular for whale-watching groups on the West Coast, attracting families and eco-tourists to places like Whidbey Island, Port Angeles and Anacortes. Everett is one of the few places in the world where gray whales can be seen feeding on ghost shrimp, which live on the seafloor near Everett and south Whidbey Island.

The whales are large, around 49 feet long and weigh around 90,000 pounds. The gray whales have mottled, gray skin. Calves are born a darker gray color and lighten into a brown-gray or light gray as they grow. Barnacles and whale lice typically latch on to the creatures near their heads and tails.

Boaters should be wary of gray whales in the waters beneath them. These whales don’t have dorsal fins like orcas and are slow-moving, so they can be hard to see. In 2017 a gray whale was hit by a recreational boat, but the whale has since recovered, Gless said.

Boaters are reminded to travel slowly, look for blows, and not approach within 100 yards of the gray whales. The “Whale Warning Flag,” adopted in 2018 and displayed by many whale watching and research vessels, also signals that whales are nearby and that boaters should take caution.

Other dangers to gray whales come from fishing gear – the whales are at risk of getting tangled in nets and swimming around caught in it, or becoming trapped in a net. Underwater noise can also affect whales by interrupting their normal behaviors. Whales may begin avoiding certain areas critical to their survival, according to NOAA, and evidence suggests underwater sound may cause some whales to strand and die.