Pandemic Gives Pacific Northwest Whales A Respite From Din Of Underwater Noise

Eba, the whale dog, uses her nose to alert researchers to floating whale poop, which can then be scooped up for analysis.
Eba, the whale dog, uses her nose to alert researchers to floating whale poop, which can then be scooped up for analysis. CREDIT: Deborah Giles / UW Center For Conservation Biology

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American and Canadian marine scientists — and one talented dog — are seizing an unexpected opportunity presented by the coronavirus pandemic. They are trying to establish whether Pacific Northwest whales benefit from the current drop in boat traffic and underwater noise.

Stay-home edicts have significantly reduced recreational boat trips and ferry crossings this spring. Commercial whale watching tours and the cruise ship season remain on hold. Large cargo ships continue to come and go with slightly reduced frequency.

Noise and vessel disturbance are considered major factors in the decline of the Northwest’s endangered resident orcas alongside the other big factors of dwindling food supply — chiefly, chinook salmon — and toxic pollution.

“From a killer whale’s perspective, not having fast moving boats around like recreational boats… that might be quite beneficial,” said oceanographer Scott Veirs of Seattle, who coordinates an underwater microphone network called Orcasound.

The coronavirus-induced lull in marine traffic may be short-lived, meaning researchers have to act fast to document if the quieter seas make happier, healthier whales.

Multiple researchers who were interviewed described an ultimate objective to correlate whale health and behavior changes — for example, by measuring stress hormone levels — with separate datasets of underwater noise levels and boat densities on the surface. The fortunes of the critically-endangered Southern Resident killer whales have high priority, but transient orcas, gray whales, humpback whales and other baleen whales are of interest too.

Killer whale expert Deborah Giles ventured out into Haro Strait in recent days looking to scoop up floating poop left behind by any passing whales for multiple levels of analysis. She encountered the marine mammal-eating transient orcas, also called Bigg’s killer whales.

“Specifically right now, we’re interested in looking at stress levels,” Giles said in a brief interview as she was leaving Snug Harbor on San Juan Island, Washington, on Friday. “Hopefully, at some point being able to compare them with stress levels in fecal samples collected at other times of the year and possibly even next year to see whether or not this low-boat data is having an impact.”

Eba, the whale dog, at work in Haro Strait on May 8.

Eba, the whale dog, at work in Haro Strait on May 8. CREDIT: Deborah Giles / UW Center For Conservation Biology

A specially trained dog stood in the bow of Giles’ boat to help her locate whale scat for collection. Giles teaches at the University of Washington as well as serves as research director for the nonprofit Wild Orca.

Veirs said there is a bit of suspense in the research community about when the three pods of endangered Southern Resident orcas will arrive for their traditional late spring and summer residency in inland waters. J pod has made a couple of brief forays into the Salish Sea during late winter and this spring, but soon reverted to foraging out of sight off the Pacific Coast.

“We are all trying to remain ready,” Veirs said. “If the pandemic continues to affect vessel traffic in the Salish Sea for the next couple of months, we’ll have a very rare opportunity to observe killer whale activity when noise levels are reduced. I hope that happens.”

The population of resident killer whales in the shared border waters of the U.S. Pacific Northwest and southwestern British Columbia has dwindled to around 73 individuals.

The fish-eating orcas primarily use sound to hunt, orient and communicate. Buzzy, high pitched noise from small recreational boat engines can mask the clicks and chirps the killer whales make for echolocation of prey (also called biosonar).

Other larger whales that inhabit Northwest waters communicate over longer distances in a frequency band that overlaps with the rumbling, low frequency noise made by large container ships, tankers and bulk freighters.

Oceanographer Scott Veirs sets up a hydrophone to listen to ships and orcas at Bush Point, Whidbey Island, in 2018.

Oceanographer Scott Veirs sets up a hydrophone to listen to ships and orcas at Bush Point, Whidbey Island, in 2018. CREDIT: Eilis O’neill / KUOW Photo

The Olympia-based Cascadia Research Collec