A group of killer whales was spotted looking for a meal in Vancouver Harbour this week.
The Bigg’s killer whales, also known as transient whales, were seen Tuesday hunting for seals – a more common occurrence as the weather warms up.
Unlike resident orcas, Bigg’s whales feed on marine mammals like seals, sea lions, dolphins and other whales.
“Harbour seals are popular prey for these apex predators and they’re discovering hot spots where they can find an abundance of them — it appears the Vancouver harbour might be one of those spots,” said Lance Barrett-Lennard, director of the Vancouver Aquarium’s Marine Mammal Research Centre, in a news release.
Exactly one week ago, a different pod of Bigg’s whales was seen hunting in the harbour. Some of the oldest members were born as far back as 1986, according to researchers.
They are still threatened under the Species at Risk Act, but B.C.’s population of Bigg’s are recovering, now at more than 300. Barrett-Lennard pointed to the healthy population of seals and sea lions as a main reason for the growth.
Researchers at the centre have been conducting a multi-year study of killer whales in the northeast Pacific Ocean, using unmanned drones to collect high-resolution images they then analyze to measure growth rates and changes in body condition.
They hope to determine whether orcas are getting their basic nutritional requirements, and to look at the impact of fluctuations in salmon population on body condition.
The study comes as calls grow to bring back the sea lion cull to protect Chinook salmon – the main food source for resident orcas, but not transients.
“Killing pinnipeds to protect Chinook salmon and help resident killer whales is akin to robbing Peter to pay Paul,” he said.
“A cull of the seal population in the Salish Sea would negatively impact mammal-eating killer whales, and because seals eat more salmon predators than they do salmon, it could even harm the fish-eating whales.”