Environment
9:09 am
Fri July 8, 2011

Marlin, blue fin tuna could become regulars in Northwest waters

NEWPORT, Ore. – Climate change may push fish native to the Northwest coast further northward and bring fish from southern waters up here.

That's according to a forthcoming study by American and Canadian fisheries biologists. They suggest West Coast fishermen will need to adapt to different prey if the Pacific Ocean warms as projected over the next fifty years.

The science team studied 28 fish species whose current distribution on the West Coast is well known. Fisheries oceanographer Ric Brodeur of the NOAA Northwest Fisheries Science Center in Newport says the list includes salmon, smelt, sharks, pollock and sardines.

Global warming

Brodeur says the researchers simulated what could happen if the North Pacific heats up due to global warming.

"Because these fish are so mobile, they can move up and down the coast or inshore or offshore to find the preferred temperature that they want," Brodeur said.

The federal science agency NOAA predicts for the ocean's surface waters off Oregon and Washington will warm about 2 degrees Celsius over the next 50 years.

Mapping the migration

Brodeur says that's enough to cause significant moves. A forthcoming research paper models how much.

If you combine the home ranges of all the fish that the team studied, there's an average shift northward of roughly 25 miles per decade. Over time, Brodeur predicts fishermen and seafood consumers will notice.

"A lot of the species that we consider very important – like hake – things that are commercially fished here might be gone and replaced by other species that may or may not be commercially important."

Robert Waddell, a veteran charter fishing boat captain out of Yaquina Bay, says he's already seen some evidence of warm water species shifting northward.

"I've noticed in the last 12-13 years, we've been starting to see some marlin off and on out there and we've hooked them a few times," Waddell said.

A changing fishery

Blue fin tuna is another possible newcomer that could fill the vacancy if, say, salmon left for cooler waters off Canada.  Waddell is optimistic the local fishing fleet can adapt.

"People will make adjustments.  Fifty years from now we might be the marlin capital of the world.  You never know."

The study of the northward fish shift should appear in a science journal in about six months.

Copyright 2011 Northwest News Network