21.9 C
Ontario
Wednesday, July 28, 2021

Heat waves put new stress on B.C.’s already struggling salmon


A sweltering heat wave in much of Western Canada in the last week of June had cascading effects on sea life, experts say.

Scott Hinch, director of the Pacific salmon ecology and conservation laboratory at the University of British Columbia, said juvenile salmon such as sockeye, coho and chinook in fresh water would have been most affected by recent heat waves.

“They’re going to be living in fresh water for one to two years and it’s that life history stage, that this particular heat wave and just climate change in fresh water in particular, is going to have some of its greatest effects,” he said in an interview.

Read more:
Heat wave: More than 800 died in B.C. in a single week, four times more than normal

Juvenile salmon live in fresh water for up to two years and the heat wave in that part of their life cycle has some of its greatest effects, he said.

Story continues below advertisement

Surface waters are warmer than they have been historically, Hinch said.

“And they’re staying warmer longer because of just general increases in air temperatures associated with climate change,” he said.

“The heat waves just make things that much worse.”


Click to play video: 'Extreme heat wave responsible for mass die-off of B.C. seashore creatures'







Extreme heat wave responsible for mass die-off of B.C. seashore creatures


Extreme heat wave responsible for mass die-off of B.C. seashore creatures – Jul 6, 2021

Salmon in British Columbia are already at risk due to a combination of factors, including changing climate, mining, logging, habitat loss and the Fraser River landslide.

The Fraser is one of the largest spawning rivers in the world and the landslide, discovered in 2019, decimated early runs of Stuart sockeye and chinook salmon.

The Committee on the Status of Endangered Wildlife in Canada has classified Sakinaw sockeye, Okanagan chinook and certain species of Fraser sockeye as endangered. It classified Interior Fraser coho and some of Fraser sockeye as threatened and is assessing the status of chinook.

Story continues below advertisement

Hinch said the ideal water temperature for salmon is between 12 C and 18 C and they can only stand the heat for so long.

Read more:
Up to a billion seashore creatures were cooked to death during B.C. heat wave, researcher says

The heat wave in June where the all-time Canadian temperature record was set saw water in streams hit the mid-20s, “and those are really stressful for juvenile salmon, and lethal,” he said.

“We start seeing really bad things happening when temperatures are at 24 degrees or above.”

There’s a lot less oxygen in warm water and deep water is cooler than the surface, where the juvenile salmon need to feed.

The warmer temperatures also affect plankton and other small fish that salmon eat, he added.

While there is a “sweet zone” that these fish usually call home in lakes during such high temperatures, he said it limits their ability to move around, forage and undertake their normal behaviours.

Now that the top of the lakes are warm, they won’t be cooling soon because churning up the cooler water takes strong air currents and winds that aren’t common in the summer months, he said.


Click to play video: 'REPORT: Heat wave and fires driven by climate change.'







REPORT: Heat wave and fires driven by climate change.


REPORT: Heat wave and fires driven by climate change.

Christopher Harley, a marine biologist at the University of British Columbia, said the recent heat wave saw temperatures higher than 50 C in seabeds and along rocky areas along parts of the shore. Around the same time, the mercury at the Vancouver International Airport hit the mid-30s.

Story continues below advertisement

“The rock is very hot and then it’s bouncing all that heat back,” Harley said.

“If you were living in the shade, if you were a mussel on the north side of a rock, you probably survived, but if you were in the sun, then you were in trouble.”

Read more:
Heat wave: As B.C. bakes, what role does climate change play?

He estimates the heat wave caused the death of more than a billion marine animals along the Pacific coast, including mussels, barnacles, seaweed and sea anemone.

“The more places I visit, the more I realize it’s going to be a lot higher than that. It’s a growing list,” he said of the dying sea life.

Hinch said he’s most troubled about juvenile salmon in small streams that can’t take refuge in deeper areas. Their options are limited to migrating to other waters or simply dying, he said.

“We are going to be leaving a much hotter, hotter world. And how salmon are going to be able to adapt and maintain themselves under those conditions is still the great uncertainty.”

He said every year brings new record temperatures and new record water conditions.

Story continues below advertisement

“Just like we predicted it would 30 years ago, but we’re kind of seeing it playing out now.”




© 2021 The Canadian Press





Source link

Latest news

US Secretary of State Antony Blinken meets representative of Dalai Lama in Delhi | India News

NEW DELHI: US Secretary of State Antony Blinken met with a representative of Tibet`s spiritual leader, the Dalai Lama, in New Delhi on...

For Rakesh Asthana, new role as Delhi Police Commissioner comes as vindication

Just four days before his superannuation, the Modi government has given a plum assignment to Gujarat-cadre IPS officer Rakesh Asthana as Police Commissioner...

Bihari Aashiq in Bhojpuriya Kapil Sharma show | by Jp Yadav

1xBet website link: USE PROMOCODE: «JPYADAV» and get 130% bonus up to ₹10 000 DOWNLOAD ANDROID APP: DOWNLOAD iOS APP: written by_ Jp Yadav editing_Hariom facebook:-- instagram:- plese...

Tokyo Olympics: PV Sindhu trumps Hong Kong’s NY Cheung, advances to knockout stage | Badminton News

PV Sindhu dictated the proceedings in the women's singles clash against Hong Kong's NY Cheung, winning the contest 21-9, 21-16. With this win, Sindhu...
Related news

US Secretary of State Antony Blinken meets representative of Dalai Lama in Delhi | India News

NEW DELHI: US Secretary of State Antony Blinken met with a representative of Tibet`s spiritual leader, the Dalai Lama, in New Delhi on...

For Rakesh Asthana, new role as Delhi Police Commissioner comes as vindication

Just four days before his superannuation, the Modi government has given a plum assignment to Gujarat-cadre IPS officer Rakesh Asthana as Police Commissioner...

Bihari Aashiq in Bhojpuriya Kapil Sharma show | by Jp Yadav

1xBet website link: USE PROMOCODE: «JPYADAV» and get 130% bonus up to ₹10 000 DOWNLOAD ANDROID APP: DOWNLOAD iOS APP: written by_ Jp Yadav editing_Hariom facebook:-- instagram:- plese...

Tokyo Olympics: PV Sindhu trumps Hong Kong’s NY Cheung, advances to knockout stage | Badminton News

PV Sindhu dictated the proceedings in the women's singles clash against Hong Kong's NY Cheung, winning the contest 21-9, 21-16. With this win, Sindhu...