VANCOUVER — Whale watching companies in the Salish Sea report unusually large groups of humpback whales are becoming a frequent sight off B.C.'s south coast.
The Pacific Whale Watch Association says the number of whales is unprecedented around the southern end of Vancouver Island.
Association executive director Michael Harris says humpback whales were a rare sight off the south coast just 20 years ago, but have become increasingly common over the last three or four years.
He says whales usually travel in groups of two or three, but the latest sightings are unique because they are in groups of up to 20, mirroring conditions he says occur only off Alaska or Hawaii.
Rhonda Reidy, a naturalist and whale watching boat captain, is about to begin a PhD study of what are termed the "comeback humpbacks" of the Salish Sea, arguing shifts in oceanographic and ecological conditions may be affecting the food chain.
She says humpbacks can feed on krill and small schooling fish, such as sardine, anchovy and herring, but their exact diet isn't known, and she believes more data could explain the robust return.
"Just an expanse of whales filling the seascape," says Harris in a news release.
"They're breaching like crazy, pec slapping, rolling at the surface, vocalizing, and most importantly, doing a lot of lunge feeding. They definitely seem to be finding plenty to eat, especially off Port Angeles and Victoria, and that may be a good sign."
The co-founder of Washington-based Cascadia Research Collective, John Calambokidis, works closely with the association to follow the huge whales and agrees a shift in habitat may be involved.
"We've had lots of humpback whales offshore in past years and now more of them are coming into the inland waters. That's probably due to the increased numbers overall, likely resulting in expanded areas of use, but also something to do with prey availability, which at this point is harder to determine in detail," he says in the release.
The association says researchers believe there are now more than 21,000 humpbacks in the eastern North Pacific, up from about 1,600 when whale hunting was banned in 1966.
