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

First Police Board meeting Thursday a ‘pivotal moment’ in Surrey’s history, mayor says

The 10 a.m. “virtual” meeting Aug. 6 will be live-streamed and details on tuning in will be available at surrey.ca/policeboard

BC ACORN report calls on Surrey to help renters

Report contains steps on how the City of Surrey can “ease” the city’s housing crisis

Keno machine shutdown was no tech glitch, it was $50K prize for Surrey woman

Ticket checked at the Panorama Shell store in Surrey

Parking facility for 100 trucks coming to North Surrey at cost of $30M

‘It’s often difficult to find suitable parking for large transport trucks,’ says association boss

Man rescued from overturned sailboat near Crescent Beach

‘Luckily he had a lifejacket on, that’s the only thing that probably saved his life,’ rescuer says

B.C. records 146 new COVID-19 cases through long weekend

More that 28 people tested positive for the virus each day since Friday

Alberta to require masks at schools this fall, but still no mandate in B.C.

B.C. students are also set to return to classrooms in September

Gangster Jarrod Bacon released from prison for third time

Parole board continues to express concerns about Bacon’s behaviour

B.C. to allow customers to buy cannabis online for in-store pickup at private shops

Age verification will still be required inside the store

30% of British Columbians would ‘wait and see’ before taking COVID vaccine: poll

Some are concerned about side effects, while others don’t think the virus is a big deal

UPDATE: Man injured in targeted shooting in Maple Ridge

Shots fired from one vehicle into a white Hyundai

What exactly is ‘old growth’ B.C. forest, and how much is protected?

Forests minister Doug Donaldson doesn’t support ‘moratorium’

Don’t leave your hand sanitizer in the sun and other tips to stay COVID safe this summer

Being mindful of staying outside and keeping hand sanitizer, sunscreen out of the sun recommended

Canadians can travel to Hawaii in September; no quarantine with negative COVID test

Travellers will be required to pay for their own tests prior to arriving

Most Read

l -->