77% of fish and seafood caught globally are expected to decline over the next few decades, including a dramatic drop in sockeye salmon. Could tuna be a beacon of hope?
Researchers warn that marine heatwaves made more extreme and more frequent by climate change could wipe out up to half of Canada’s Pacific salmon catch by 2050.
The study, led by a group of researchers at the University of British Columbia and published Friday October 1 in the journal Science Advances, modeled the trajectories of 10,088 fish and invertebrates across the world’s oceans.
“This will have a particular impact on coastal communities, especially First Nations communities that depend on salmon,” said William Cheung, director of UBC’s Institute of Oceans and Fisheries and lead author of the study. .
Overall, he found that 77 percent of the fish and seafood already caught is expected to decline over the next few decades. This is expected to result in a significant loss of income from fishing in countries where thousands of people depend on the sea for their livelihood.
In Ecuador, rising ocean temperatures were already expected to lead to a 25% drop in fishing income; marine heat waves are expected to drop the country’s annual catch by an additional 10 percent.
Bangladesh’s low elevation already faces an existential threat due to rising sea levels. The study predicts that the country’s fishing-related workforce – which employs about a third of all workers. workers – will hemorrhage more than one million jobs by 2050 due to extreme ocean heat events. And in Indonesia, three million more jobs are expected to disappear by mid-century.
“This will definitely have an impact on the fish supply globally,” Cheung said. “It has a direct impact on people here. ”
“Canadians eat seafood, but we get fish from all over the world. If you go to the supermarket and go to the frozen seafood aisle, most seafood comes from one of those tropical regions – Indonesia or Thailand. ”
While over 10,000 species were included in the projections, any species not important to the fishery were excluded. Cheung says this leaves huge data gaps for countless numbers of marine animals that will inevitably be hit just as hard by warming seas.
But not all species will be negatively affected by marine heat waves, Cheung says. Tuna, for example, actually like hot water and increase its distribution as the sea temperature rises.
“The point is, we are already seeing some of these changes happening. During episodes of high temperatures in recent years – what we call the “hot spot” – we see some of these tuna species in the northeast Pacific, including British Columbia, ”says Cheung.
When added together, the slow warming of the world’s oceans and the temperature peaks during marine heat waves are expected to reach their highest intensity in the Pacific Ocean.
Tropical waters are expected to be hit harder. Yet, says Cheung, it is up to countries like Canada to take action.
“We can moderate the effects on fish stocks, so they can… maintain them until we are able to reduce emissions in the long term,” he says.
This means better data collection to get a quick understanding of the number of fish in a given season as well as restrictions on commercial catches.
That future is already here.
The Fraser River, Canada’s largest salmon river, recorded an average of 9.6 million sockeye returns per year between 1980 and 2014, of which up to 28 million per year. In 2020, salmon returns dropped to an all-time high of 293,000 salmon returned to the Fraser River. The 2019 comeback set the previous record at 485,000.
Cheung says that with climate change impacting these returns even more, the province will only close more fisheries.
“It’s scary, but it matches what people have seen in their streams and rivers across British Columbia,” says Aaron Hill, executive director of the Watershed Watch Salmon Society of the latest research.
Hill spoke to Glacier Media while on the banks of the Skeena River, where the chinook fishery was totally closed in June and where record-breaking rainbow trout returns could soon mean they will. facing their very first shutdown.
“These are just examples of the unprecedented changes we’re seeing here in British Columbia,” he says. “It underscores the importance of doing everything we already know to give salmon the best chance to survive and thrive in the face of climate change.”
This includes creating recovery plans for endangered species, protecting and restoring freshwater habitat, moving fish culture to terrestrial enclosures, and responsible management of hatcheries so that the problem does not occur. ‘Don’t make it worse, says Hill.
In June, Ottawa pledged nearly $ 650 million over five years to deploy such measures to restore salmon populations, but few details have been released on how and where the money would be spent.
There are positive signs that current conservation efforts are paying off. This summer, the federal government shut down 60%. 100 of the commercial salmon fisheries.
On the Skeena, Hill says he sees some abundance returning to the river this year.
“But it was in the absence of commercial fishing on the coast, at the mouths of the rivers,” he says. “It actually works. “
Stefan Labbé is a solutions journalist. That means it explains how people react to issues related to climate change – from housing to energy and everything in between. Do you have a story idea? Get in touch. Send an email to [email protected]