Our planet is changing. So is our journalism. This story is part of the CBC News initiative, entitled “Our Changing Planet”, to show and explain the effects of climate change. Stay up to date with the latest news on our climate and environment page.
In the midst of the British Columbia Thermal Dome in June 2021, Chris Harley, a professor in the Department of Zoology at UBC, traveled to Lighthouse Park in West Vancouver to measure water temperatures and observe how marine animals inhabit the coast. of British Columbia, cope with extreme conditions.
He expected to see a degree of extinction, but instead was greeted with the overwhelming stench of rotting flesh like sea creatures cooked in the open with bulging shells.
In the days that followed, Harley and his students estimated that billions of sea creatures perished when temperatures rose above 40 degrees Celsius and the water temperature reached 56 degrees Celsius.
Ten months after the crash off the coast of British Columbia, researchers have returned to combing the beaches of British Columbia, checking for signs that vital populations of seaweed, crustaceans and crustaceans originating from the coast are seeing a renaissance.
“There are some reasons for optimism. Seeing the little teenagers come in is a good sign. But the system is broken, “said Harley, who has been studying the West Coast since 1995.
“Yesterday I was closer to the White Rock and it still looks like a bomb went down there – a lot of death and destruction.”
Harley said that while the ecosystem shows promising signs of resilience, it is now uniquely vulnerable to the dangers of another heat dome. And the collapse of even one population has cascading effects on others. For example, many of the rocks, usually smoothed green and brown with algae, are now bare, leaving small shells in the sun.
“Once all species return, we know that a diverse ecosystem is more resilient to this type of insult. But if you get another big disturbance, another big heat wave, before the ecosystem has a chance to recover, it could actually do more damage than it would otherwise, “Harley said.
Harley and his students explored the coastline from Victoria to Souk and White Rock and all the way north to Bamfield, Budget Sound and the Georgia Strait. They measure the number of sea creatures that repopulate by performing random quadrant searches – placing a square and counting the creatures that fall inside it, then zooming in to estimate mortality.
Early discoveries show that species with mobility had a higher survival rate due to their ability to find shade and cooler enclaves. But those anchored to rocks, such as starfish and mussels, did worse. Skulls and mussels planted on the northern sides of the cliffs have often survived, while those on the southern side of the cliff have completely disappeared in many places.
Ten months after the crash off the coast of British Columbia, researchers have returned to brush up its beaches, checking for signs that vital populations of seaweed, shells, mussels, starfish and crab originating off the coast are seeing a renaissance. (Gian Paolo Mendoza / CBC)
Harley warns that British Columbia’s beaches and waters will be transformed if species such as mussels and shells are replaced by populations that thrive at higher temperatures.
“Mussels and shells filter a lot of waste into the water. What would False Creek look like if we lost these filters or replaced them with something that might work a little differently? “There are questions we didn’t even imagine asking before last summer, because we didn’t expect something like this to happen so quickly,” he said.
“I expect in another five, 10, 15 years, this will be, instead of a beach dominated by mussels, it will be more a beach dominated by oysters. And it may actually look like subtropical parts of East Asia at this stage. “
Harley and his students are not the only group to look at how climate change is affecting waters off British Columbia
William Cheung, a marine biologist at UBC, analyzed 340 restaurant menus in the Vancouver area between 1880 and 2021 as he searched for alternative datasets to determine how climate change would affect fish populations.
His research, which also looks at the menus of Anchorage and Los Angeles restaurants, found that the preferred water temperature of seafood served to customers is getting warmer and warmer.
“We have found a significant increase in the temperature of seafood that restaurants have been serving since the 1980s,” Cheung said.
“One of the interesting things is that the increase is closely linked to changes in seawater temperature, as well as the composition of the species that fishermen catch in relation to the changing temperatures during this period.”
William Cheung, a marine biologist at UBC, analyzed 340 restaurant menus in the Vancouver area between 1880 and 2021 as he searched for alternative datasets to determine how climate change would affect fish populations. (Gian Paolo Mendoza / CBC)
Chung said Humboldt squid, a type of hot water, was almost non-existent on restaurant menus before the 1990s, but has become more common in recent years. He also predicts that sardines, a warm-water species facing a population collapse in the 1950s, will once again become a staple on British Columbia restaurant menus as they float downstream to warmer waters.
But salmon, a favorite of many British Colombians, may be far less available in the near future as it faces a habitat collapse.
“People may think that the effects of climate change in the oceans are distant, but our study shows that climate change affects everyone,” Cheung said.
Harley said he hoped the shellfish and mussel populations had proved resilient – but he remained concerned about the potential for another dangerous heat wave in 2022.
The analogy I use is when you get sunburn, it’s bad. If you get a second sunburn before the first one heals, then you are more likely to get skin cancer. And the system is still not cured, “he said.
“I think environmentalists like me have been caught in the act because things are changing faster than we expected.
Add Comment