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)

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

An Island Health nurse prepares a dose of COVID-19 vaccine. (Photo courtesy Island Health)
Health authority opening 19 clinics to immunize Vancouver Island residents

Health authority anticipates more than 40,000 people will be immunized over the next month

(PQB News file photo)
Some frustrated Parksville Qualicum Beach residents now tossing recyclables in garbage

Option is driving to collection centres in Nanaimo and Courtenay

Mike Garland, fundraising member of the Oceanside Community Track committee, visits the PQB News/VI Free Daily studio. (Peter McCully photo)
PQBeat: Mike Garland’s group wants an updated running track in Parksville

Podcast: Talk includes fundraising, plans to upgrade aging facility and more

Elvira D’Angelo, 92, waits to receive her COVID-19 vaccination shot at a clinic in Montreal, Sunday, March 7, 2021, as the COVID-19 pandemic continues in Canada and around the world. THE CANADIAN PRESS/Graham Hughes
‘It’s been a good week’: Tam hopeful on vaccines as pandemic anniversary nears

Tam says the addition of two new vaccines will help Canadians get immunized faster

Const. Allan Young. Photo: Abbotsford Police Department
Manslaughter charge laid in Nelson death of Abbotsford police officer

Allan Young died after an incident in downtown Nelson last summer

(The Canadian Press)
‘Worse than Sept. 11, SARS and financial crisis combined’: Tourism industry in crisis

Travel services saw the biggest drop in active businesses with 31 per cent fewer firms operating

Pictures and notes in from friends and classmates make up a memorial in support and memory of Aubrey Berry, 4, and her sister Chloe, 6, during a vigil held at Willows Beach in Oak Bay, B.C., on December 30, 2017. THE CANADIAN PRESS/Chad Hipolito
Mother of slain daughters supports recent changes to Canada’s Divorce Act

Sarah Cotton-Elliott said she believed her children took a back seat to arranging equal parenting

An active transportation initiative is being planned for Electoral Area G of the Regional District of Nanaimo. (PQB News file photo)
RDN: Active transportation planning sought for French Creek area

Consultant to be hired to undertake $85,000 project

The Port Alice pulp mill has been dormant since 2015. (North Island Gazette file photo)
Parts recycled, life returning to inlet as as old Port Alice mill decommissioned

Bankruptcy company oversees de-risking the site, water treatment and environmental monitoring

Victoria man Brett Andersen is asking for people’s help to secure him one of eight free tickets to the moon. (Screenshot/@brettandersen Instagram)
Victoria man wants your help securing a free ticket to the moon

Japanese billionaire offering eight people a trip to the moon

The Conservation Officers Service is warning aquarium users after invasive and potentially destructive mussels were found in moss balls from a pet store. (BC Conservation Officers Service/Facebook)
Aquarium users in B.C. warned after invasive mussels found at pet store

Conservation officers were told the mussels were found in a moss ball from a Terrace pet store.

Most Read