This Sept. 26, 2019 photo shows coastal waters off Greenwood State Beach where The Nature Conservancy is mapping and monitoring one of Mendocino County’s last remaining bull kelp forests near Elk, Calif. (AP Photo/Terry Chea)

Scientists breathe easier as marine heat wave off west coast weakens

Area of exceptionally warm water is substantially smaller now than it was earlier this year

Scientists say a marine heat wave that blanketed a large area of the west coast has weakened, but the potential disruption to ocean life isn’t over yet.

Nate Mantua of the National Oceanic and Atmospheric Administration said the ”good news” is that the area of exceptionally warm water is substantially smaller now than it was earlier this year.

And while the area about 1,500 kilometres offshore between Hawaii and Alaska is still seeing high temperatures by historical standards, it is “simply not nearly as large as it was and it is no longer strong in areas near the west coast,” he said.

Scientists have been watching a marine heat wave that developed around June this year and resembled a phenomenon that was nicknamed ‘The Blob,’ which disrupted ocean life between 2014 and 2016.

The heat wave, which resembles a wedge this time, stretched from south of Vancouver Island to Baja, Calif., and offshore towards Hawaii. It raised temperatures by up to 4 C.

Mantua said “many energetic storms and unusually strong winds from the north off the west coast” have cooled surface waters back to near normal temperatures for much of the region.

“On the other hand, the offshore warming is still in place, and by historical standards, it is still a large marine heat wave,” he said in an email.

The latest climate model forecasts from the National Oceanic and Atmospheric Administration’s Climate Prediction Center suggest that the offshore warming will gradually weaken over the next seven months, but even by spring will still be warmer than normal, Mantua said.

ALSO READ: Students skip school, join climate strikes across B.C.

Prof. Andrew Trites at the University of British Columbia’s Institute for the Oceans and Fisheries said the marine heat wave is caused when there is not enough wind to churn and cool the water.

“This past summer winds were very, very light — not strong enough for ocean to be mixed the way it used to be in the past. As a result the ocean didn’t cool down the way it was supposed to and it’s holding its heat,” he said in a phone interview.

“It’s not that the ocean got warmer, it’s really that the ocean did not get cooler.”

As a result, some species of tropical fish that are usually seen in tropical waters were found off the west coast, he said.

“One of the fish that I saw a lot of this summer was the sunfish and presumably they are here in higher numbers because the water here was unusually warm this summer and they can tolerate warm temperatures,” Trites said.

Mantua said the most obvious impacts included a pattern of unusually low plankton production from July through September from Vancouver Island to northern California.

Warm waters near the coast of northern California, Oregon, and southern Washington brought albacore tuna closer than normal to the coast, and sport fishing was especially good there this summer, he said.

However, ocean salmon fishing in those areas was generally poor, Mantua said.

“All that said, I have not heard of any reported ecosystem impacts in those offshore waters where it remains very warm,” he said.

“I suspect that the extreme warming in the productive part of the open ocean has had some impacts, but there simply isn’t a lot of information coming from those regions aside from satellite observations of ocean colour that tell us some general information about plankton production.”

There is a chance that the marine heat wave might return, Mantua said, although he thinks “the odds for that are low, at least based on the latest climate forecasts.”

Trites said the first time this heat wave occurred about five years ago, it was thought that it would never happen again.

“So this may be an example of climate change and global warming. It is changing the patterns of air circulation and affecting storminess and it’s not going to mix the water the way it used to.”

Hina Alam, The Canadian Press

Get local stories you won't find anywhere else right to your inbox.
Sign up here

Just Posted

Kelowna resident seeks help locating missing ferret

Dexter the Ferret is smaller than average and likes to chase squirrels

KF Aerospace Centre unveils building plans for museum at YLW

The museum and conference centre is intended to be built on Lapointe Drive beside the Kelowna International Airport

Morning Start: One Year on Uranus Is 84 Years on Earth

Your morning start for Wednesday, Sept. 23, 2020

Four-hour wait time to book child’s COVID test concerns Kelowna parent

Interior Health is asking for patience as they experience an increase in calls and testing requests

Attorney General defends Kelowna Mountie involved in rough arrest

Tyler Russell filed a lawsuit against Const. Siggy Pietrzak in June of this year

B.C. reports 96 new COVID-19 cases, one hospital outbreak

61 people in hospital as summer ends with election

Refresh of Liberal government’s agenda comes amid new looming COVID-19 crisis

Lockdowns saw fed spending soar to historic levels in effort to offset pandemic’s blow to Canadians’ livelihoods

‘Unprecedented’ coalition demands end to B.C. salmon farms

First Nations, commercial fishermen among group calling for action on Cohen recommendations

Is it time to start thinking about greener ways to package cannabis?

Packaging suppliers are still figuring eco-friendly and affordable packaging options that fit the mandates of Cannabis Regulations

Earthquake off coast of Washington recorded at 4.1 magnitude

The quake was recorded at a depth of 10 kilometres

Join Black Press Media and Do Some Good

Pay it Forward program supports local businesses in their community giving

B.C.’s top doctor says she’s received abuse, death threats during COVID-19 response

Henry has become a national figure during her time leading B.C.’s response to the COVID-19 pandemic

Suspected human remains found in burned out vehicle on OKIB land

Vernon North Okanagan RCMP hand over investigation to Major Crimes

Kamloops RCMP search for armed robber of pizza restaurant

The incident unfolded on Monday evening at the Sahali Domino’s store

Most Read