Australian diners have an insatiable appetite for seafood, consuming around 350,000 to 400,000 tonnes a year.
But a new report is warning that some of the traditional fishing grounds for migratory species like tuna are exposed to climate change.
The research, led by the non-profit Marine Stewardship Council (MSC), found the fish will divert to cooler waters as the oceans warm.
In Australia, most people will be blissfully unaware of the problem, because no matter where it is caught, the majority of product eaten there is processed in Thailand, the world’s biggest exporter of canned tuna.
But for many of Australia’s island neighbours supplying the Thai canning industry and fresh markets, the impact could be devastating. For them, tuna fishing is big business – worth an estimated US$4.9 billion (AUD$7.5 billion) a year in the Western Central Pacific Ocean.
Rosemarie Palu, an Australian who runs longline fishing operations out of Tonga’s capital Nuku’alofa, said tuna stocks are “definitely declining”.
“The research is showing that the fish are moving out of Tongan waters,” she told Yahoo News.
She and her Tongan husband, Eddie Palu – who captains one of their six vessels – think the next decade is likely to be “okay” for them, but looking further ahead, they’re worried.
“The tuna industry in the Pacific is going to be pretty bad, say, 20 to 30 years from now, because of climate change. Because it’s going to get worse,” Eddie said.
They’ve already witnessed the fish moving further away from Tonga’s exclusive economic zone. And this means accessing the fish requires using more fuel, a commodity that’s surging in price and impacting their bottom line.
“Going forward, the tuna fisheries in the Pacific will be nothing like what we used to know. It will be getting less and less as the tuna move away into international waters, Central Pacific and move east towards South America,” he said.
“It’s going to be a big problem for all the Pacific islands that survive on tuna fisheries.”
To maintain a healthy supply as the tuna move to new locations, MSC has warned quotas will need to change, and more cooperation will be needed between nations.
Australia-based Bill Holden now works as MSC’s global head of tuna, but before taking on the role, he was a fisherman in Tonga.
Thinking back to when he started in the industry in the late 1980s, his catch would fluctuate depending on how many vessels were permitted to operate. But the biggest impact on tuna stocks was El Niño and La Niña – two intense systems that illustrate how weather impacts migration.
“With El Niño, the warm water moves eastward, and so the fish do too. And it’s the opposite for La Niña,” he told Yahoo News.
The MSC report warns that as climate change further disrupts tuna availability, tensions between developing Pacific nations could intensify.
This concern is shared by the manager of the Common Oceans Tuna Project, Joe Zelasney, who said the loss of fish availability could be “devastating” to some small island states.
“It’s crucial that governments and regional organisations work together now to safeguard livelihoods and food security,” he said.
The study’s lead author, MSC data science manager Lauren Koerner, said as fish move into new jurisdictions, quota agreements between nations that ensure the catch is sustainable quickly become “obsolete”.
“Climate change is redrawing the map of the sea,” she said. “If we want sustainable tuna for future generations, we must redraw our management boundaries too.”
The research was published in the journal Cell Reports Sustainability, and was a joint project between MSC, experts from the Universities of Queensland, NSW and Tasmania, Griffith University, and CSIRO.
