Most of B.C.’s marine mammals are flourishing, so why aren’t orcas?

A trio of humpback whales delayed ferry traffic this week, wowing passengers who caught them on camera.

It’s not your imagination, nor is it a side effect of having a recording device in everyone’s pocket: There are, in fact, more marine mammals in and around British Columbia waters.

And while most species are flourishing, there’s one seeing its population fail to thrive: salmon-eating orcas.

“The perception is true that overall our marine mammals have rebounded and they’re doing extremely well, with one exception,” said UBC marine mammal professor Andrew Trites. “Southern resident killer whales, despite everything’s being done, have not improved.”

Related: Ferry passengers treated to unexpected humpback whale encounter in Horseshoe Bay

The Washington-based Center for Whale Research has just published its annual count finding the overall population grew by just one whale in the last year, with four surviving calves born as two others and an adult died.

Michael Weiss, research director for the institute, explained that those orcas are picky eaters and survive mostly on a single species of salmon, “so when you see declines in the abundance and size and quality of Chinook salmon prey, that’s when you see these declines in southern resident killer whales.”

Related: Southern resident killer whales show signs of slow decline toward disappearance

He pointed out that the growing northern resident killer whale population gets first dibs on the fish as they migrate from Asian waters, and that while seal-eating transient killer whales are similarly thriving, that doesn’t mean the public should give a collective shrug at the slow decline of the three southern pods.

“I really think, fundamentally, the world is made emptier and uglier and worse every time we lose a species or a culture or society,” Weiss said. “Southern residents are really, really unique, even among killer whales.”

While he worries about the future of those orcas, Trites is encouraged every time he sees another social media post or news story about whales spotted by shore-bound admirers since it seems to encourage even greater conservation efforts.

“There’s so much effort and attention being paid to ensuring that we protect them and that they are allowed to thrive here in our waters,” he said. “I often see the marine mammals that are here as the ambassadors of the Salish Sea – they’re speaking up for others that don’t have a voice.”