Mama orca and sons spotted in Vancouver harbour frequently in area hunting for seals

The pod of orcas spotted swimming under a Vancouver bridge on Tuesday, deep in the inner harbour, are no strangers to the area.

The family of transient killer whales, a mother and her three grown sons, came in close to the city looking for a meal of seals — something scientists say is becoming more common as the seal population steadies.  

"Vancouver gets very excited every time we get killer whales coming right into the Burrard Inlet because it's not super common," said Caitlin Birdsall, a researcher with the B.C. Cetacean Sighting Network at Ocean Wise

"But we're seeing them more and more in the area."

This particular family of whales are well-known to scientists on the West Coast.

"We know exactly who these whales are," Birdsall said, citing their distinctive markings and fins that make them recognizable.

"They are quite distinct because it's three big males who travel with their mother."

The female, known as T-101, has been spotted off B.C.'s coast stretching back to 1973.

The offspring she travels with are 35, 26 and 21 years old.

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The draw of increased prey

Transient whales, unlike southern resident killer whales, feed on marine animals like seals and sea lions.

Often, the whales swim through undetected or stay just outside the city's waters, farther into English Bay and Howe Sound.

But they are getting more brazen.

"We have seen more and more sightings of them in this area that we think is tied to the draw of increased prey," Birdsall said.

In particular, the whales are coming into busy inlets and bays looking for harbour seals.  

There used to be bounties for harbour seals and their population dropped down to about 10,000 in the 1970s.

Now, a few decades since seal hunting came to an end, there are about 10 times that number in B.C.'s coastal waters.

"We're back to historical levels of harbour seals, and these transient killer whales are discovering different hotspots where they can find those rebounded populations," Birdsall said.

"So, I think we'll continue to see activity by this type of killer whale in and around the waters of Vancouver."