Overfishing could spell the end of yellowfin tuna stock in the Indian Ocean in less than a decade

The organisation responsible for managing tuna fishing quotas in the Indian Ocean failed to make headway on saving the sector’s most imperiled species, yellowfin tuna (Thunnus albacares), at the body’s annual meeting this month. Members of the Indian Ocean Tuna Commission did, however, take steps to prevent another tuna stock, bigeye tuna (T. obesus), from going the yellowfin way.

The end value of tuna fisheries from the Indian Ocean is around $8 billion annually, according to an analysis by Washington, DC-based think tank The Pew Charitable Trusts.

The gathering of Indian Ocean Tuna Commission parties, which include coastal states that border the Indian Ocean and distant-water fishing entities, most notably the European Union, was held in Mauritius from May 8-12. There was little progress on key issues surrounding yellowfin, like reducing annual catch for the overfished stock and limiting the use of harmful fish-aggregating devices used by purse seine fishing vessels.

Although the Indian Ocean Tuna Commission declared yellowfin tuna overfished in 2015, to date, the intergovernmental regional management body has failed to curb overfishing, particularly the capture of juveniles. The Indian Ocean yellowfin population could be headed for collapse as early as 2026, conservation group Planet Tracker says.

“When it comes to yellowfin tuna, we are eating our capital,” Umair Shahid, WWF’s Indian Ocean tuna specialist, said in a statement. “Unless we take action now to radically reduce annual catch, there won’t be enough stock left to harvest in less than 10 years.”

The European Union, which operates a purse seine fleet in the region and has historically pulled in the largest share of yellowfin tuna, is promoting the commercial interests of its fleet despite the clear threat, critics say. This has pitted many coastal states against the bloc, which deploys vastly disproportionate lobbying muscle during tuna negotiations.

In recent years, the Maldives, a small island nation in the western Indian Ocean, has led a group of parties in proposing measures that target the industrial purse seine fleet. The collective catch of artisanal fishers from dozens of coastal countries now rivals the share of the European Union’s industrial fishing fleet, pulling in about a third of the tuna catch. But observers say these small-scale fisheries support coastal communities and contribute to local economies, while the large purse seiners pull in profits for big companies.

Mongabay earlier reported on European Union-based companies reflagging vessels to smaller island nations like Seychelles and Mauritius to circumvent Indian Ocean Tuna Commission regulations and benefit from allocations and concessions granted to smaller island nations by the regional body.

In February, during a special session on fish-aggregating devices, countries worked on a proposal to reduce the use of drifting fish-aggregating devices, free-floating platforms that attract fish. These drifting fish-aggregating devices allow purse seiners to scoop up large schools of tuna and other fish, netting large numbers of juveniles. This indiscriminate fishing method hampers the population recovery of yellowfin populations.

The European Union objected to stricter drifting fish-aggregating devices measures adopted this year, effectively nullifying the ambitious plan adopted by a two-thirds majority in February. A handful of other countries, including coastal states Kenya and Oman, also filed objections. Both these countries declared their intentions to introduce purse seiners into their fleets and increase their catches of yellowfin tuna.

Objecting parties are not obliged to enforce the resolution for their fleets. According to an analysis by BLOOM, a France-based nonprofit, the European Union’s Indian Ocean tuna fleet is responsible for 95% of tuna catches made around fish-aggregating devices.

Other tuna stocks could face a similar crisis without effective measures from the Indian Ocean Tuna Commission. No progress was made on sustainably managing populations of skipjack tuna (Katsuwonus pelamis), a species that, like yellowfin and bigeye, the Indian Ocean Tuna Commission has declared as being fished at unsustainable levels.

But the body did take action on bigeye tuna. The regional management body declared the Indian Ocean bigeye stock overfished in 2022. At the annual meeting, parties agreed to a 15% reduction from 2021 levels in the permitted annual bigeye catch.

Another silver lining from this year’s meeting was the Indian Ocean Tuna Commission’s adoption of electronic monitoring standards that rely on artificial intelligence and remote sensing to track catch volumes and species. This will promote science-based decision-making at the Indian Ocean Tuna Commission, according to supporters of the standards like Glen Holmes, a senior officer for The Pew Charitable Trusts’ international fisheries program.

“They will expand much-needed monitoring and increase data collection on fisheries that operate far from the reach of land-based enforcement officers and scientists,” Holmes said. “These standards set a new precedent that should be mirrored in other oceans.”

Delegates to the May meeting also accepted two proposals aimed at reducing the bycatch of seabirds and marine mammals like dolphins and whales. However, they did not adopt a resolution banning the use of fishing gear designed to target sharks that the Maldives put forward.

“Unfortunately, all this progress may be overshadowed by IOTC’s failure, yet again, to reach a compromise to get management of yellowfin and skipjack tuna under control,” Holmes said.

This article was first published on Mongabay.