Pacific Whale West
Last year’s record-breaking number of sightings of Bigg’s killer whales and humpback whales in the Salish Sea and what they mean for the ecosystem’s health.
A Bigg’s killer whale and humpback whale face each other as they breach. A fascinated onlooker in a sailboat observes with binoculars. // Illustration by Jacob O’Donnell
Story by Jacob O’Donnell
March 27, 2023
Bigg's killer and humpback whale sightings shattered records in the Salish Sea in 2022. Whale watchers spotted Bigg’s killer whales 1,221 times and humpback whales 396 times last year, according to the Pacific Whale Watch Association in a press release.
Humpback whales and killer whales are quite different from each other, despite the fact that they’re both called “whales” (killer whales are a species of dolphin). What they do have in common is intelligence, culture, strong family bonds and a high aptitude for learning, according to National Geographic’s Secrets of the Whales documentary series. Another thing they have in common is that they’re both on the rise in the Salish Sea.
The Salish Sea is a vast inland estuary encompassing the Puget Sound, the Georgia Straits and the Strait of Juan De Fuca. Historical patterns of hunting, pollution, overfishing and other human impacts have caused some marine mammal species to decrease.
The fact that some are recovering so well is encouraging to whale watchers like Tasli Shaw. Shaw is a co-founder and project lead at Humpback Whales of the Salish Sea, and she works with Canada’s Department of Fisheries and Oceans on photo identification.
“Personally, I would say that is a conservation victory, as a change in our human behavior resulted in the recovery of an entire species,” Shaw said in an email interview.
Transient (Bigg’s) Killer Whales
Bigg’s killer whales are one of two types of orcas found in the Salish Sea. Their fish-eating cousins, southern resident killer whales, are endangered and struggling to recover from a lack of Chinook salmon–their main food source.
On the other hand, Bigg’s killer whales are enjoying a rising number of seals, sea lions and other prey, according to Cindy Hansen, the education and advocacy coordinator at the Orca Network.
Transient orcas swimming together in the Salish Sea. // Photo courtesy of Cindy Hansen
Seals and sea lions are part of the pinniped family. They are so-called because they have a fin as a foot and use it to move around on land, according to the National Oceanic and Atmospheric Association website.
Between 1900 and 1972, commercial hunting dramatically reduced pinniped populations in the Salish Sea. Those populations are now returning to their pre-hunting levels, thanks to the Marine Mammal Protection Act (MMPA) of 1972. Seals may be exceeding pre-hunting populations, according to Hansen.
“While the southern resident orcas are endangered with their top threat being lack of salmon, the Bigg's orcas are a conservation success story due to abundance of prey,” Hansen said in an email.
Currently, there are over 350 Bigg’s killer whales that make the Salish Sea their home for at least part of the year, according to the Orca Network.
Killer whales may be some of the most intelligent creatures on the planet. They have the second largest brains of any marine mammal species, weighing in at 15 pounds. Orcas display this intelligence through their complex language systems, strong kinship with fellow pod members and sophisticated teamwork while hunting.
Bigg’s killer whales have been seen jumping onto beaches to scare seals into the water for their family to catch. Scientists herald it as ingenious since seals and sea lions tend to escape orcas by going on land.
But the bounty of prey they’ve enjoyed since the 1970s may be under threat once again. Some experts and activists in the Salish Sea region want to increase salmon by reducing pinniped populations.
Salmon is just a small part of a pinniped’s diet, according to Hansen.
“As for food sources, seals and sea lions are generalists,” Hansen said. “Pinnipeds eat a variety of fish and invertebrate species so they will vary their diet based on what is available.”
Pinniped culling is a controlled reduction of population and may have unintended consequences beyond a potential reduction of Bigg’s killer whale populations, according to Alejandro Acevedo-Gutierrez, a biology professor at Western Washington University. He is also head of WWU Marine Mammal Ecology Lab.
“Culling of pinnipeds in other regions indicate changes in the ecosystem given that pinnipeds are prey of some species, consume fish of commercial importance and also consume predators of fishes of commercial importance,” Acevedo-Gutierrez said in an email interview. “Given all this information, we do not know the potential impact any potential culling will have on the ecosystem as a whole.”
No seal culling programs have taken place in the Salish Sea yet and they would have to be approved under the MMPA, Acevedo-Gutierrez said.
Increased prey may not be the only reason that Bigg’s killer whale sightings rose so much last year, according to Hansen.
“It is possible that there are more eyes on the water, more people familiar with the two ecotypes of orcas, and documenting and reporting their sightings,” Hansen said. “But that goes hand in hand with more Bigg's orcas in the Salish Sea overall.”
Humpback Whales
Humpback whales are the sixth largest species of whale in the world, with lengths of about 52 feet and weights between 28 and 33 tons. Humpbacks are filter feeders, specialized in screening krill and small fish out of the water. They are also one of nature’s longest travelers, with the Pacific population swimming about 5,000 miles from the equator where they birth their calves to the North Pole where they feed.
One of their stops along the way is the Salish Sea.
“[The] increase in humpback whales in the Salish Sea is not unique to us; the same increase has been documented up and down the coast,” Shaw said. “There are no fences to impede these whales, so with increased numbers in many regions there will be some degree of mixing, helping to explain where some of these whales are coming from.”
A humpback whale breaching near the shore. // Photo courtesy of Jean Beaufort via PublicDomainPictures.net
Before bans on whale hunting were implemented in 1985, humpback whales coming to the Salish Sea swam to their doom. Over 5,600 whales were killed along the British Columbia Coast during commercial whaling, Shaw said.
By the early 1900s, there were none left in the Salish Sea, according to a report by the British Columbia Ocean Watch. Now there are about 400.
“Not chasing them down with harpoons anymore was an obvious boon to their recovery,” Shaw said.
But there are still threats to them such as collisions with boats and entanglement in fishing gear, according to B.C. Ocean Watch.
Fluctuating prey may also limit the number of humpbacks that return from year to year, according to Shaw.
“The North Pacific is a complicated and temperamental ecosystem, which can shift prey availability for the whales on large scales,” Shaw said.
For now, prey is abundant for the humpbacks that come to the Salish Sea, which has a direct relationship with the number of whales that are coming to the region according to Shaw. Small fish are also prey for salmon and pinnipeds, which in turn are food for orcas, according to B.C. Ocean Watch.
“There are questions remaining about where some of these whales are coming from, as the natural fecundity of the most commonly encountered whales doesn't completely explain the rapid increase,” Shaw said. “This means that at least some of the whales seen here are likely part of a much larger group that possibly uses the entire offshore B.C. and Washington region as their feeding range.”
The same is true of Bigg’s killer whales, which patrol the coast from Alaska to Central California, making the Salish Sea a rest stop on a much broader journey.
The Salish Sea still has enough abundance to be worth the stop for many whales and is an encouraging sign of the ecosystem’s recovery, said Shaw.
Jacob O’Donnell is a fifth-year student at Western Washington University majoring in environmental policy and public relations. He has interned and written for WWU’s Communications Office and the Navajo Nation Washington D.C. Office.