How the humpback whale made a massive comeback in the Salish Sea

ABOARD THE MOLLY B, on the Salish sea — They are big. They are beautiful. And they are back.

The return of the humpback whale to greater numbers than observed in decades is part of a larger revival of marine mammals in the Salish Sea. It is an astonishing sight of life rebounding, with exception of the endangered southern residents orcas.

On a recent day in the waters of the San Juan Islands, pink salmon were jumping, and masses of sea birds were feasting on forage fish. Baby seals lazed alongside their mothers on the rocks, too sleepy to be bothered by a boat quietly chuffing by. The quick dives of harbor porpoise, with their tiny dorsal, knifed the water. Minke whales, too, sliced the surface.

It’s in these conditions the humpbacks have made a spectacular recovery at about 8% a year.

Until about the 1910s humpback whales were common, but then they were hunted to near extinction by commercial whaling.

“You never saw them,” said Joe Gaydos, science director for the SeaDoc Society, a science and education nonprofit based on Orcas Island. “Now they are showing up in places where they had not been seen since the 1900s. Now we see them willy-nilly, spring, summer, fall, winter.”

It’s a reminder, Gaydos said, of the difference policies to protect and preserve animals and their habitat can make.

Shifting policies

It is a resurgence for an animal once so relentlessly pursued. There once were whaling stations from California to British Columbia, including at Bay City in Grays Harbor. Commercial whaling of humpbacks for their baleen and blubber reduced their population by more than 95%, according to the National Oceanic and Atmospheric Administration.

The last whaling stations in the U.S. operated out of San Francisco Bay until 1970. Commercial hunting of humpbacks was banned by the International Whaling Commission in 1966. The commission placed a moratorium on commercial hunting of all whales worldwide in 1986. Subsistence hunting by aboriginal groups is allowed under special provisions. Some countries, including Japan, in 2019 withdrew from the IWC convention and continue to hunt whales commercially.

Other environmental laws, including the Clean Water Act and Endangered Species Act, and the Marine Mammal Protection Act, as well as modern sewage treatment all have made for cleaner water, and more abundant life in the Salish Sea. “It didn’t used to be this way; we did something right,” Gaydos said. “It is important to remember and celebrate the victories.”

Tracking the populations

John Calambokidis, senior research biologist and a founder of the Cascadia Research Collective in Olympia, has been studying humpbacks for nearly 40 years. With other researchers he has assembled a photo catalog of humpbacks, uniquely identifiable by marks on their flukes, or tail. There are thousands of them.

Seeing just two humpbacks in Puget Sound was noteworthy in the 1980s, Calambokidis said. Today, the number of humpbacks has grown by an order of magnitude from about 500 on the West Coast to more than 5,000, including about 2,000 in Washington and southern B.C. waters, Calambokidis said.

Today humpbacks migrate thousands of miles between their feeding and breeding areas. The humpbacks found in the waters of Washington and southern B.C. primarily comprise mixed herds of humpbacks from Mexican and Hawaiian populations. The Mexican population, which is legally treated as distinct, is listed as threatened under the U.S. Endangered Species Act. All humpback populations are protected under the Marine Mammal Protection Act.

With the growth of the overall population has come the recent return of humpbacks to feeding areas including offshore of the mouth of the Columbia River, San Francisco Bay and the Salish Sea, where humpbacks hunt both fish and krill, a tiny shrimplike crustacean.

Mammalian marvels

Humpbacks are baleen whales with large bony plates in their mouth, rather than teeth. They are able to switch prey. In Washington waters, humpbacks feed on fat-rich forage fish as well as krill.

The fact the humpbacks are here feeding is a good sign for the food web in the Salish Sea; they would not be here, Gaydos said, if they weren’t finding masses of the fish they need.

Found in nearly all the world’s oceans, humpbacks are gigantic. Big as a school bus, the females can be up to 60 feet long and weigh up to 44 tons; males are slightly smaller. Yet for their size, they are graceful swimmers, easing through the water with arched dives of their humped back that give them their name, and lifting their flukes as they dive. And what flukes they are, nearly 20 feet wide. Their pectoral fins are the largest of any whale, nearly a third as long as their body. Those fins inspired their scientific name, Megaptera, meaning big-winged. Primarily black in color and salted with barnacles, humpbacks are long-lived, cruising the oceans for on average up to 80 years, with some living into their mid-90s.

They have a variety of feeding strategies.

Humpbacks can lunge-feed, swimming fast into a dense school of fish, and opening their mouth at the last moment, creating a suction effect that traps masses of fish, said Elliott Hazen, research ecologist with the NOAA’s Southwest Fisheries Science Center’s lab in Monterey, Calif. Humpbacks also can team up to form a net of bubbles that confuses and traps fish, allowing the whales to gulp them while swooshing upward through the bubble net.

Humpbacks are known for their playfulness, especially their spectacular breaches, lifting their entire body out of the water and landing with a crashing splash. Hazen photographed the breach of a humpback named Minnow in the Stellwagen Bank National Marine Sanctuary so spectacular that the photo wound up on a U.S. postage stamp.

Hazen calls humpbacks the pigeons of the sea because of the wide variety of prey they devour — but they have a bit of policeman in them, too. Humpbacks are known to harass killer whales — the ocean’s top predator — seeming to go out of their way to protect other species from them. “Is it altruistic, are they just being good stewards of the ocean environment, or do they know if they harass the orcas it means they won’t predate their calves?” Hazen said. Nobody knows for sure.

Killer whales are major predators of humpback calves, Calambokidis said. About 20% of humpbacks show scars from killer whale attacks, primarily when they were calves.

Humpbacks are perhaps best known for their low, moaning songs, sung by the males especially to attract mates, but also by both genders during migration, and for communication. A recording of whale songs made by Roger Payne, “Songs of the Humpback Whale” (1970) was a smash hit.

The songs are long and complex, lasting at least 10 to 20 minutes, and repeated for hours at a time. They can be heard at least 20 miles away, with the lower frequency tones carrying even farther.

Persistent threats

While humpbacks’ natural predators include sharks and killer whales, many more are scarred and even killed by humans: Entanglement is one of the gravest dangers to humpbacks, along with ship strikes, particularly as larger numbers of humpbacks attempt to survive among even more humans, with their boats, ships, ferries and fishing fleets.

Most ship strikes go unreported, the whales sinking to the bottom along with the story of what killed them.

Changes in ocean food webs wrought by ocean warming caused by climate change and particularly marine heat waves are also compressing humpback habitat as they move closer to shore to find food. That proved especially treacherous during the marine heat wave of 2014-16, which saw a big spike in humpback and gray whale entanglements — particularly in the gear of Dungeness crab fishers.

Even after that heat wave subsided, entanglements remain above levels of the past — and are increasing at rates faster than population growth — due to both the presence of more whales and their overlap with the most prosperous fishery on the West Coast, Calambokidis said.

It’s just one more aspect of an increasing challenge of human wildlife conflicts all over the globe, as climate change pushes animals and people into each other’s space, resulting in everything from more crocodile, lion and shark attacks on humans to more killings by people of elephants and snow leopards. Briana Abrahms, biologist at the University of Washington Center for Ecosystem Sentinels, in a 2023 paper documented increased human and wildlife conflict caused by climate warming on six continents and all five oceans.

Here at home, the risk of entanglement is growing. A gruesome death, entanglement in fishing gear kills by drowning, starvation and deep, painful wounds.

“We don’t want this job,” said Gaydos, pointing to tools used by a small cadre of professionally trained experts who respond to reports of entangled marine mammals: grappling hooks, cutting tools, buoys and more.

Working to free a whale from ropes and buoys and other gear is dangerous; the animal could thrash, with disastrous results for the rescuers. Popular myths that entangled whales “understand” humans are there to help them are just that, Gaydos said. No one but trained experts should ever attempt to disentangle a marine mammal. Call 877-767-9425 or a local U.S. Coast Guard station on Channel 16 if you encounter an entangled marine mammal.

Three trends are helping to drive increased harm to whales by entanglement and ship strike: bigger ships, faster ships and more ships, Calambokidis said. Speed kills, and so does putting shippers and whales on collision courses, particularly at night when humpbacks commonly come to the surface to rest and follow prey migrating up in the water column.

At least two humpbacks have been inadvertently struck and killed by Washington State Ferries.

Ships have grown so large that pilots likely don’t even know when they have hit a whale. Likely 10% or less of ship strikes are ever detected and reported, Calambokidis said.

He advocates moving transit routes farther offshore and away from the productive areas where fish draw feeding whales. “By reducing the overlap, we can reduce the risk,” he said.