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

Interior Health leading the way with innovative therapy for stroke patients

Percentage of ischemic stroke patients who received treatment has risen dramatically

Missing Nelson woman found dead

Police say there is no evidence of a crime in the death of Heather Gunderson

Foul play involved in Slocan Valley man’s death, police say

RCMP have identified dead man as 47-year-old Aaron Graham

Hidden message connects Castlegar homeowners decades apart

The Rodgers family was surprised when a message fell out of the walls as they were renovating

Supreme Court of Canada will hear Sinixt appeal May 12

B.C. has appealed Indigenous hunting case through several levels of court starting in Nelson in 2016

VIDEO: Minister says consider coronavirus outbreak when planning for spring break

Foreign Affairs minister points to rash of new cases appearing in places like Italy and Iran

B.C. man who pulled a gun on off-duty cop gets two years in prison

Encounter also led police to a home where 100 guns and explosives were found

Protecting privacy key to stopping spread of COVID-19, B.C. health officials say

The number of coronavirus cases in B.C. remains at seven

COLUMN: Forestry no longer close to top of B.C.’s economy

Our reactions to a forestry downturn reflect the past, not the present

Caught on camera: Police release video of man who allegedly stole seaplane in Vancouver

Police say the man broke into the Harbour Air terminal and then got into one of the seaplanes in the harbour

51 health professionals send letter to Trudeau, Horgan panning northern B.C. pipeline

They point to studies about the health and climate change risks from pipeline

Fake meat and a latte? Starbucks adds Beyond Meat in Canada

The Seattle roaster has talked about introducing plant-based patties in the U.S., but has yet to do so

Most Read