Climate change: Retreating glaciers are creating new salmon habitat, B.C. study shows
The retreat of glaciers in the Pacific mountains of British Columbia and Alaska could produce thousands of kilometres of potential new salmon habitat, a study led by researchers at Simon Fraser University shows.
The study published Tuesday inNature Communications projects that more than 6,000 kilometres of new streams could be accessible to salmon by 2100,and just under one-third of that could be suitable for spawning.
Of the total kilometres of new streams that could be gained with “complete deglaciation,” the study projects 23 per cent would be created by 2050.
To make the projection, researchers identified 315 glaciers at the headwaters of existing streams and linked their retreat with five different models of global climate change along withresearch of potential salmon habitat across 623,000 square kilometres of coastal B.C. and Alaska.
“What this illustrates is how some of these salmon ecosystems are being rapidly transformed by climate change,” said Jonathan Moore, co-author of the study and a professor of biological sciences at the university. “While climate change poses dire challenges for salmon in many parts of their life cycle, it also might pose some opportunities in some locations.”
The study cites earlier research that found a population of pink salmon grew to include more than 5,000 spawning adults within 15 years of a new stream and lake system emerging following glacier retreat in Glacier Bay, Alaska.
The researchers used modelling to “peel back the ice” for about 46,000 glaciers across Pacific mountain ranges, identifying 315 that feed streams with a suitable slope and flow for salmon,explained Kara Pitman, the study's lead author and a post-doctoral fellow at the university.
It projected that a further 3,300 kilometres of streams could be created by a total of 603 retreating glaciers with a somewhat higher threshold for stream slope. About half the glaciers in the study area are located in steep terrain that would be inaccessible to migratory salmon, particularly in B.C., it notes.
The analysis suggests the greatest gains in potential salmon streams would occur where large glaciers are located in low-slope terrain near the coast, with the highest increase of 27 per cent projected in the Gulf of Alaska.
The study notes that glacier retreat can also be associated with increased natural hazards that could affect salmon, such as floods and landslides.
The newly created streams would likely be quite cold with a lot of sediment, but over time, they could become productive salmon habitat, Moore said.
Salmon are very good at homing or finding their way to their usual spawning grounds, but between one and 10 per cent of a population may stray, he said.
“There are always salmon out there sort of exploring and looking for new habitat. And so those strays are going to be the ones that are finding the new systems,” Moore said. The straying probably stems from the evolution of salmon in dynamic landscapes with constantly changing habitat, he added.
Fisheries and Oceans has said many salmon stocks in B.C. are declining to “historic lows” due to climate change, habitat loss and other threats.
“We can't underestimate the challenge that salmon face with climate change and multiple stressors,” Moore said.
“But there are going to be some opportunities for salmon in some places, and I think by understanding those opportunities, we can really help steward systems the best ways possible into the future.”
The study's findings help with understanding how ecosystems are changing as the climate warms, which could in turn help to guide decisions that affect how both existing and future salmon habitat is managed, Moore said.
It's much easier to protect than to restore, he noted.
Effectively protecting salmon involves “conserving not just their current habitat, but also avoiding the degradation of their future habitat,” the paper says.
This report by The Canadian Press was first published Dec. 7, 2021.
CTVNews.ca Top Stories
DEVELOPING Iran fires at suspected Israeli attack drones near Isfahan air base and nuclear site
Iran fired air defences at a major air base and a nuclear site early Friday morning near the central city of Isfahan after spotting drones, which were suspected to be part of an Israeli attack in retaliation for Tehran's unprecedented drone-and-missile assault on the country.
NEW After hearing thousands of last words, this hospital chaplain has advice for the living
In his new book 'As Long as You Need', hospital chaplain J.S. Park opens up about death, grief and hearing thousands of last words.
LeBlanc says he plans to run in next election, under Trudeau's leadership
Cabinet minister Dominic LeBlanc says he plans to run in the next election as a candidate under Prime Minister Justin Trudeau's leadership, amid questions about his rumoured interest in succeeding his longtime friend for the top job.
Prince Harry formally confirms he is now a U.S. resident
Prince Harry, the son of King Charles III and fifth in line to the British throne, has formally confirmed he is now a U.S. resident.
Trend Line Anger, pessimism towards federal government reach six-year high: Nanos survey
Most Canadians in March reported feeling angry or pessimistic towards the federal government than at any point in the last six years, according to a survey by Nanos Research.
Colin Jost names one celebrity who is great at hosting 'Saturday Night Live'
Colin Jost, who co-anchors Saturday Night Live's 'Weekend Update,' revealed who he thinks is one of the best hosts on the show.
American millionaire Jonathan Lehrer denied bail after being charged with killing Canadian couple
American millionaire Jonathan Lehrer, one of two men charged in the killings of a Canadian couple in Dominica, has been denied bail.
Nearly half of China's major cities are sinking, researchers say
Nearly half of China's major cities are suffering 'moderate to severe' levels of subsidence, putting millions at risk of flooding especially as sea levels rise.
Judge says 'no evidence fully supports' murder case against Umar Zameer as jury starts deliberations
The judge presiding over the trial of a man accused of fatally running over a Toronto police officer is telling jurors the possible verdicts they may reach based on the evidence in the case.