A pod of “heroic” humpback whales came to the rescue of a desperate sea lion under attack from four cunning and hungry orcas off the coast of Sooke, a phenomenon never before seen by whale-watching operators in the Salish Sea.

The waters were glass calm on Sept. 11 when whale-watchers witnessed four humpbacks huddle around a Steller’s sea lion, slapping their pectoral fins and their flukes, “taking shots essentially, taking swings at these transient orcas,” said Michael Harris, executive director of the Pacific Whale Watch Association, which represents 38 companies operating out of B.C. and Washington.

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Whale-watchers in the area could clearly hear the humpbacks “trumpeting like we have never heard” with a ferocity that Harris said resembled a wild elephant.

Capt. Russ Nicks of Victoria-based B.C. Whale Tours, was one of the first on scene. He said it was fascinating to watch the show of aggression.

He and his guests marvelled at the strategy of one of the planet’s most sophisticated hunters as the orcas split into two groups — one to try to draw the humpbacks away while the other group went in for the kill on the sea lion.

“This is the first time I’ve ever seen anything like this,” Nicks said.

“I explained to the guests how rare this kind of interaction is.”

The humpbacks took turns diving and slashing at the orcas for about 40 minutes, until the orcas, known as the T100 family, finally retreated.

“[The humpbacks’] predator is the orca and they didn’t run away. They actually came to the aid of another mammal,” Nicks said.

Despite the handicap of lacking sharp teeth, the humpbacks used their size — between 40 and 50 tons — to their advantage.

“This was a heavyweight division going against a lightweight and the heavyweights won,” Harris said.

The humpbacks then escorted the sea lion to safety.

“So they all went to their neutral corners, if you will,” said Harris, in keeping with the boxing analogies.

The interaction confirms a study published by the Journal of Marine Mammal Science that found humpback whales will defend other marine species such as seals, sea lions and grey whale calves from orca attacks.

Harris said those in the whale-watching industry are careful not to impart human values onto marine mammals but he said it’s hard to deny the altruistic behaviour of the humpbacks, putting themselves in harm’s way to protect another species from predators.

Two researchers from Cascadia Research Collective based in Olympia, Washington, had a ringside seat from aboard a boat operated by Port Angeles Whale Watch Co., said owner Capt. Shane Aggergaard.

“I probably wouldn’t have believed the story if I wasn’t there,” Aggergaard said.

Two of the humpbacks were familiar to whale-watch operators.

A dramatic resurgence of humpbacks in waters off B.C. and Washington state has been dubbed the “humpback comeback” and has given environmentalists, researchers and marine mammal scientists ample opportunity to study a species that was on the verge of extinction a half century ago.

There are more than 21,000 humpbacks in the eastern north Pacific, up from about 1,600 when whale hunting was banned in 1966.

On Monday, whale-watching crews reported a huge congregation of about 60 humpbacks off Sooke.

In August, whale-watchers witnessed a dramatic clash between a pod of transient killer whales and two adult humpback whales and a calf near Jordan River.

The Pacific Whale Watch Association described “an epic tussle never seen before by most whale-watchers in this region.”

“We’ve got all of these whales recolonizing the Salish Sea after a half century not being here and we’ve got record numbers of transient killer whales,” Harris said. “So we’ve got two species that are recolonizing an area, and this might be a turf war.”

Aggergaard said he’s excited by the emerging science around this type of defence mechanism on the part of humpbacks.

“To know that they have this territorial, instinctual personality … maybe they’re not just great big eating machines out there,” he said.

kderosa@timescolonist.com

Two whales found dead off Island

A transient orca and a humpback whale were found dead in the waters off Vancouver Island in recent days, which has Department of Fisheries and Oceans investigating how they died.

The orca, a mature male, was found dead in Grappler Inlet near Bamfield on Thursday. A necropsy was performed Saturday, but there was no visible trauma or obvious cause of death.

The humpback was spotted last week in Quatsino Sound and is awaiting a necropsy.