Research spotlights the impact of climate change on Pacific salmon migration
Climate change is knocking some Pacific salmon out of alignment with the growth of the ocean plankton they eat to survive, new research says.
In the largest data set ever gathered on the timing of juvenile salmon migration, research found the changing climate is causing some salmon populations to migrate earlier out of step with plankton blooms that are also affected by changing weather patterns.
Lead author Sam Wilson said that as climate change continues the two will match less and less, putting salmon survival at risk.
“The coastal ocean is changing in one way and Pacific salmon are changing in a myriad of other ways and those ways don't always align,” said Wilson, a post-doctoral researcher in the salmon watersheds lab at Simon Fraser University.
Numerous species of Pacific salmon are at risk or even endangered for several reasons, including overharvesting and lack of habitat protections. Wilson suggests the response by the young salmon may be a coping mechanism that helps them survive and reinforces the need to protect biodiversity.
Wilson spent almost five years collecting data from research projects around North America on 66 wild Pacific salmon populations stretching from Oregon to British Columbia to Alaska and dating back at least 20 years.
She found that some salmon populations are migrating earlier, with pink and chum changing fastest at seven days earlier per decade, while other species saw no change on average.
On average, fish are still managing to find the plankton they need, Wilson said, but climate change means they'll be matching up with the blooms less and less.
Major events such as the marine heat wave known as “The Blob,” which persisted in the Pacific Ocean between 2013 and 2016, led to a “big mismatching event” and decreased young salmon survival, she said.
“And that was a harbinger for future climate change.”
The research found that the changes in salmon migration were not predictable, with populations of the same species of salmon behaving differently.
Wilson said that could be a challenge for people in charge of managing and protecting the species, who often use one population as an indicator to predict how the rest of the species is managing.
“So, they might say, Chilko sockeye are not changing their migration timing so we don't have to worry about it. Let's move on to the next topic,” she said.
“But those changes aren't predictable, through space and time.”
The study's authors recommend avoiding a “one-size-fits-all approach” to management, she said.
For those outside of research or salmon management, that confusing lack of predictability is something to be celebrated, Wilson said.
She said the fact that populations have responded differently is an example of biodiversity and a sign salmon have tools to deal with climate change.
“As a scientist, I can tell you if you want to preserve biodiversity, you need to preserve the habitat that underpins that biodiversity,” she said.
“This unpredictability gives me a headache as a scientist trying to predict it. It might give a manager a headache trying to predict it. But it also protects salmon. So, we need to maintain that diversity if we want to keep having salmon in our ocean, and in our lakes and on our tables in future.”
This report by The Canadian Press was first published May 4, 2023
CTVNews.ca Top Stories
Ottawa has sold its stake in Air Canada: sources
Two senior federal government sources have confirmed to CTV News that the federal government has sold its stake in Air Canada. During the COVID-19 pandemic in 2021, the government purchased a six per cent stake in the airline for $500 million as part of a bailout package.
Premiers disagree on whether Canada should cut off energy supply to U.S. if Trump moves ahead with tariffs
Some of Canada's premiers appeared to disagree with Ontario Premier Doug Ford on his approach to retaliatory measures, less than a day after he threatened to cut off the province's energy supply to the U.S. if president-elect Donald Trump follows through on his threat of punishing tariffs.
She took a DNA test for fun. Police used it to charge her grandmother with murder in a cold case
According to court documents, detectives reopened the cold case in 2017 and then worked with a forensics company to extract DNA from Baby Garnet's partial femur, before sending the results to Identifinders International.
BREAKING Travis Vader, killer of Lyle and Marie McCann, denied day parole
The man who killed an Alberta couple in 2010 has been denied day parole.
McDonald's employee who called 911 in CEO's shooting is eligible for reward, but it will take time
More than 400 tips were called into the New York Police Department's Crime Stoppers tip line during the five-day search for a masked gunman who ambushed and fatally shot UnitedHealthcare CEO Brian Thompson last week.
Man who set fires inside Calgary's municipal building lost testicle during arrest: ASIRT
Two Calgary police officers have been cleared of any wrongdoing in an incident that saw a suspect lose a testicle after being shot with an anti-riot weapon.
Country star Morgan Wallen sentenced in chair-throwing case
Country music star Morgan Wallen on Thursday pleaded guilty to two misdemeanour counts of reckless endangerment for throwing a chair from the rooftop of a six-storey bar in Nashville and nearly hitting two police officers with it.
'I recognize these footsteps': How Trump and 'coyote' smuggling changed life at the border
Bent signs bolted to the rail threaten fines and imprisonment should violators cross the boundary into the United States, a warning many people are choosing to ignore simply by walking around the barrier.
Weather warnings for hazardous conditions in parts of Canada
Canadians experienced contrasting weather on Thursday, from warmer temperatures in the Maritimes to extreme cold in parts of Ontario, the Prairies and the North.