In the deep waters of the north Atlantic, a sighting that was rare is becoming more common: the Bluefin tuna.
Fisherman Ben King recalls seeing one of the giant fish — which can weigh more than 1,000 pounds — off the coast of Cornwall.
“It looked like an enormous alien popping out of the water,” said King, founder of seafood company Pesky Fish. “You just don’t get fish of that size in our waters, so it had to be a tuna.”
Previously classified as endangered, the Atlantic bluefin is now a species of “least concern”, according to a new “red list” update from the International Union for Conservation of Nature.
Four out of the seven tuna species in the IUCN list are recovering, thanks to better fishing management and enforcement against illegal fishing.
The IUCN says fishing quotas and protected areas are responsible for the recovery, though many other marine animals remain under threat.
“We can turn things around, even with a highly commercial species like tuna,” said Craig Hilton-Taylor, head of the IUCN Red List unit.
The IUCN is launching a new “green status” list to record the species that are being saved, to mark its quadrennial gathering in Marseille this weekend, one of the biggest environmental conferences involving governments and non-profit organisations since the pandemic.
Global tuna trade catch value
Tuna are one of the most valuable kinds of seafood, worth about $42bn a year in trade, as part of an annual seafood market worth about $150bn, according to a study by the Pew Charitable Trusts.
Tuna numbers went into decline in the second half of the 20th century, and are only now starting to pick up, for certain species in certain areas, after the measures put in place in the 2000s.
“One of the challenges of managing tuna, is that they are highly migratory species,” said Mark Zimring, director of the Large-Scale Fisheries Program at The Nature Conservancy. “They are also an important indicator species because they are toward the top of the food chain.”
One of the most successful programmes to regulate tuna fishing has been in the western and central Pacific Ocean, Zimring says, a region sometimes called the “Opec of tuna fishing” because it produces about half of the world’s canned tuna. Eight countries, including small island states such as Kiribati and the Marshall Islands, have banded together to limit licenses.
According to the IUCN, the Atlantic bluefin, the Southern bluefin, albacore, and yellowfin tuna species have experienced improvements since the 2000s. For the Atlantic bluefin, its population in the Mediterranean has risen 22 per cent in the past four decades, although numbers in the Gulf of Mexico have declined.
But the endangered status of the bigeye tuna and skipjack tuna were unchanged from the previous red list, and the Pacific bluefin tuna is still considered “near threatened”.
Among other species in decline, more than a third of shark and ray species are now threatened with extinction. “With marine species, because they are under the water in the ocean, people tend to think it is an endless resource,” Hilton-Taylor said. “It’s hard [for them] to see that we are losing lots of marine life.”
The updated list also contains bad news for the Komodo dragon, which moved to the endangered category. The world’s biggest lizard is threatened by rising sea levels, which will encroach upon the islands where it lives, reducing its habitat by as much as 30 per cent in the next 45 years.
One measure under discussion at this year’s IUCN congress is a proposal to protect 30 per cent of the Earth’s lands and oceans by 2030, although the recommendations of the congress are not binding.