Ocean sunfish spotted in B.C. waters as tropical fish move north

WATCH:A large sunfish that washed up off northern Vancouver Island this weekend is just one of several tropical species migrating north. Linda Aylesworth explains.

The ocean sunfish is a gentle giant that can weigh up to 5,000 pounds and measure 14 feet in length.

“They are very docile,” said Dr. Richard Dewey of Ocean Networks Canada. “They sometimes sit at the surface for hours. I’ve actually seen a seagull land on a sunfish while sunning itself at the surface.”

Ocean sunfish are tropical creatures that seek warmth and yet one was spotted last week near Bella Bella. On Sunday, a lighthouse keeper discovered a dead one washed up on the northern tip of Vancouver Island.

They are here because their warm water range is expanding north.

The pool of warm water they inhabit–which scientists have dubbed “the blob”– has been growing in the Gulf of Alaska because the last two winters have been too mild to produce the typical big windy storms needed to disperse it.

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“Now we’re talking about waters that are 16, 17, 18 degrees that are typically 13 or 14 degrees,” said Dewey.
Sunfish aren’t the only species taking advantage of the situation.

“There are a variety of species that typically are found by the fishermen under these warm conditions,” said Dewey. “Humboldt squid is one. They are a large, large predator.”

Up to six feet long, the aggressive squid normally hunt in the waters off Mexico but they have been spotted off the west coast of Vancouver Island. Large schools of mackerel could also spell bad news for many local species.

“These warm water species may be eating the same food,” said Dewey. “The Chinook that are coming back now, they want to feed on herring, but these mackerel are also feeding on the herring.”

Mackerel and Humboldt squid also feed on juvenile salmon and it’s a situation that Dewey finds concerning and deeply fascinating.

“You have the ripple-on effects that it may not be a sustainable mode for the environment or the habitat or the fish, so we’re concerned for that, but as a scientist you’re always excited when something really extraordinary happens.”

-With files from Linda Aylesworth