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

Peninsula farm stands open for business with COVID-19 restrictions

Growers hopeful shoppers will support local farms

Income tax deadline looming

2019 individual tax returns are due June 1, June 15 for self-employed individuals

Langford’s City Centre Park cautiously reopens most activities as of Friday

Ice rink, bowling alley and restaurant to follow new regulations

VIDEO: Langford man battling cancer honored with hot rod, motorcycle procession

Friends and family support Patrick O’Hara on his 73rd birthday

‘Seven baths in two days’: Homeless adjusting to life in hotels

Victoria passes motion to allow camping 24-7 in parks until June 25

B.C. legislature coming back June 22 as COVID-19 emergency hits record

Pandemic restrictions now longer than 2017 wildfire emergency

POLL: Do you agree with the provincial government’s decision to increase the minimum wage?

B.C.’s lowest-paid workers will be getting a few more dollars to try… Continue reading

B.C.’s essential grocery, hardware store employees should get pandemic pay: retail group

Only B.C.’s social, health and corrections workers are eligible for top-ups

COLUMN: Canada needs to remember rural communities as thoughts turn to pandemic recovery

Small towns often rely on tourism, which has been decimated by COVID-19

Edmonton, Vancouver and Toronto vying to be NHL hubs, but there’s a catch

The NHL unveiled a return-to-play plan that would feature 24 teams

As SD84 schools look to reopen, Kyuquot and Zeballos opt out

Schools in Tahsis and Gold River will open on June 1, with 30 per cent students expected to come in

B.C. sees 9 new COVID-19 cases, one death as officials watch for new cases amid Phase Two

Number of confirmed active cases is at 244, with 37 people in hospital

Illicit-drug deaths up in B.C. and remain highest in Canada: chief coroner

More than 4,700 people have died of overdoses since B.C. declared a public health emergency in early 2016

CMHC sees declines in home prices, sales, starts that will linger to end of 2022

CMHC said average housing prices could fall anywhere from nine to 18 per cent in its forecast

Most Read