A transformation is taking place in the waters of Howe Sound. Researchers, residents, boaters and visitors are seeing things in the waters that haven't been seen for years or even decades.
Pacific white-sided dolphins have been spotted along with orcas and humpback whales in recent months — since the beginning of September several boaters and residents have captured orcas and humpbacks on video.
On Saturday, June 7 a pod of killer whales entertained boaters on Howe Sound when a group of at least four whales swam all the way to the tip of the sound. This followed another reported killer whale sighting on June 15.
The whales visiting Howe Sound are transient orcas, explained Kate Birdsall of the Vancouver Aquarium, who is keenly interested in the killer whales and other cetaceans found in B.C. waters.
They are also known as Biggs, she said — a nod to whale researcher Dr. Michael Biggs.
"Anecdotally most scientists will tell you there has been an increased use of the Strait of Georgia and places like Howe Sound by Biggs, or transient killer whales, or the marine-mammal-eating type of killer whale in the last few years," said Birdsall.
The data collected from citizen scientists by the BC Cetaceans Sightings Network comes from mariners, coastal residents and others who spend time on or near the water. They report the whales, dolphins, porpoises and sea turtles they see. Birdsall said the information gathered through opportunistic sighting reports isn't solid enough at this point to be considered anything more than anecdotal evidence, but researchers are analyzing the data collected so far by citizen scientists.
Research into the orca whales has revealed they come in three varieties. A great deal is known about the resident orcas — they feed on salmon and sharks — though very little is known about shark-eating, off-shore orcas.
According to Birdsall, the Biggs seen in Howe Sound feed primarily on harbour seals.
While Birdsall and other whale researchers are still pulling the opportunistic sighting information together she is able to confirm that killer whale sightings in Howe Sound are increasing.
"That is probably attributed to the fact that we have nice big, healthy populations of harbour seals," said Birdsall. "Harbour seals are their main prey species. They eat a different variety of marine animals but they eat an awful lot of harbour seals."
Up until the 1970s harbour seals were culled due to the belief they were taking too many salmon.
"Harbour seal populations were quite low and then they built up and built up over the last couple of decades," said Birdsall. "The Biggs, or transient killer whales, are realizing there's a lot here and they're using that area more and more."
Harbour seals eat small reef and shallow-dwelling fishes like rockfishes, greenlings, smelt, perch, herring and flatfishes. They also feed on salmonids, as they leave their river homes.