Orcas hunt and kill dolphins off B.C. coast; rare attack captured on video

CTV Vancouver: Clash between orcas and dolphins Penny Daflos reports on an incredibly rare and bloody confrontation between two iconic west coast mammals.

A rare and bloody confrontation between a group of killer whales and a school of dolphins stunned onlookers in Nanaimo, B.C. on Monday.

An estimated eight or nine orcas trapped several dolphins in Nanaimo's Departure Bay before they attacked the mammals – eventually killing and eating two of them.

Dozens of passengers aboard a nearby ferry and passersby on the shore witnessed and recorded the attack.

"It was crazy because by the time we drove down and parked, the whales were actually hunting -- fast, in and out," one witness told CTV Vancouver.

Experts say the attack witnessed Monday could become more common as both the dolphin and whale populations in the area increase.

"This area is so much more alive in some ways than it was 20 years ago," said Dr. Lance Barrett-Lennard, a senior marine mammal scientist with Vancouver Aquarium. "We have a lot more harbour seals, a lot more white-sided dolphins, which were gone for many years."

The whales involved in the attack were Biggs killer whales, which typically feed on other mammals, unlike resident killer whales that eat fish.

Barrett said the attack, while gruesome, points to a balancing act between the mammal populations.

"The fact that this area has recaptured some of its original dynamism in terms of marine mammals, that’s good thing," he said.

With a report from CTV Vancouver's Penny Daflos