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

The property at 113 and 161 Island Highway is currently being dismantled as the developer attempts to salvage ‘usable’ lumber for their development application to the City of Parksville. (Mandy Moraes photo)
Development application delayed for high-profile Parksville property

Council refers application to staff for further improvements

(File photo)
RCMP warn of counterfeit bill use in Parksville Qualicum Beach area

Police have received four calls in November regarding bogus bills

The COVID-19 pandemic had an effect on film production on central and north Vancouver Island, says Vancouver Island North Film Commission. Pictured here, production of TV series Resident Alien in Ladysmith earlier this year. (Black Press file)
Film commissioner says COVID-19 cost central Island $6 million in economic activity

Jurassic World: Dominion, Chesapeake Shores among productions halted due to pandemic, says INFilm

Dr. Sandra Allison is Island Health’s medical health officer for the central Island. (Photo submitted)
OPINION: Don’t let fear take over during the pandemic

Central Island medical health officer shares her reflections riding the bus

A woman wears a protective face covering to help prevent the spread of COVID-19 as she walks along the seawall in North Vancouver Wednesday, November 25, 2020.THE CANADIAN PRESS/Jonathan Hayward
911 new COVID-19 cases, 11 deaths as B.C. sees deadliest week since pandemic began

Hospitalizations reach more than 300 across the province

Black Press Media and BraveFace have come together to support children facing life-threatening conditions. Net proceeds from these washable, reusable, three-layer masks go to Make-A-Wish Foundation BC & Yukon.
Put on a BraveFace: Help make children’s wishes come true

Black Press Media, BraveFace host mask fundraiser for Make-A-Wish Foundation

West Vancouver Island’s Ehattesaht First Nation continues lock down after 9 active cases were reported today after a visitor tested positive last week. (Ehattesaht First Nation/Facebook)
Ehattesaht First Nation’s COVID-19 nightmare: nine active cases, a storm and a power outage

The Vancouver Island First Nation in a lockdown since the first case was reported last week

The Ahousaht First Nation confirmed its first case of COVID-19 on Nov. 26, 2020. (Westerly file photo)
Ahousaht First Nation on lockdown over COVID-19

“Emotions are high. The anxiety is high. We want our community to pull through.”

Screenshot of Pastor James Butler giving a sermon at Free Grace Baptist Church in Chilliwack on Nov. 22, 2020. The church has decided to continue in-person services despite a public health order banning worship services that was issued on Nov. 19, 2020. (YouTube)
2 Lower Mainland churches continue in-person services despite public health orders

Pastors say faith groups are unfairly targeted and that charter rights protect their decisions

Penny Hart is emotional outside the Saanich Police Department as she pleads for helpt to find her son Sean Hart last seen Nov. 6 at a health institution in Saanich. (Devon Bidal/News Staff)
VIDEO: Mother of missing Saanich man begs public to help find her son

Sean Hart last seen leaving Saanich mental health facility Nov. 6

A big job: Former forests minister Doug Donaldson stands before a 500-year-old Douglas fir in Saanich to announce preservation of some of B.C.’s oldest trees, July 2019. (B.C. government)
B.C. returning to ‘stand-alone’ forests, rural development ministry

Horgan says Gordon Campbell’s super-ministry doesn’t work

Most Read