VANCOUVER - When the first white-sided dolphin showed up in Echo Bay in the Broughton Islands about 13 years ago, Billy Proctor had no idea what it was.
Proctor, who grew up in the Broughtons, near the north end of Vancouver Island, had never seen one of the mammals before. Now he sees hundreds of them daily hanging out close to shore.
“They just keep increasing,” Proctor said in an interview on his satellite phone. “I guess their population is probably exploding because there’s tons of babies everywhere. I don’t think they’re supposed to be here.”
Marine biologists are also stumped as to why dolphins, which are typically found in offshore waters near the north and west side of Vancouver Island, are being seen more often in the inlets and closer to shore.
In May, nearly 200 Pacific white-sided dolphins were sighted around Howe Sound, a rare phenomenon.
Lance Barrett-Lennard, a zoologist with the Vancouver Aquarium, said the arrival of dolphins closer to shore is a treat for most people because few have seen them outside the aquarium.
On his recent travels up near Bella Bella, Barrett-Lennard said he saw few dolphins in offshore waters, while 15 years ago they were plentiful.
“I was a bit worried when I first went up where I usually see dolphins and there weren’t any,” he said. “For some reason they seem to be further inshore.”
Dolphins started moving closer to land in the mid-1980s but the reason is still unknown. It could have been a result of a food shortage it was before a moratorium was imposed on the drift-net squid fishery or changing water temperatures.
Barrett-Lennard said a recent rash of attacks on dolphins by transient killer whales may have also been a factor. In Fitz Hugh Sound earlier this year, 20 dolphins were killed by killer whales, he said, while there have been sightings of killer whales closing in around schools of dolphins in other areas.
John Ford, of the federal department of fisheries and oceans, said dolphins often play with resident killer whales, but when they see a transient killer whale they’ll go the other way.
Proctor said he was concerned when he saw a group of dolphins attacking a humpback whale recently.
“They were just leaping on his back. If I didn’t scare them away they would have killed that humpback whale.”
But Ford and Barrett-Lennard said while dolphins can be aggressive and frustrate humpbacks, they can’t kill them.
Barrett-Lennard said the dolphins are likely stealing the whales’ food by breaking up schools of fish. Humpback whales need tight schools of fish to feed on.
“Dolphins do harass humpbacks sometimes,” he said, adding they will also nip at the whales’ flukes.
But while there are more sightings of dolphins, marine biologists say there likely isn’t a huge population growth as dolphins, which can live for 40 years, reproduce slowly.
© Copyright (c) The Vancouver Sun