New management plan allows limited catch increases but mandates automatic reductions if the population declines again
Countries managing tuna fisheries in the Eastern Pacific Ocean have agreed on a long term harvest strategy for Pacific bluefin tuna, a species that has made a substantial recovery after decades of overfishing.
The agreement was reached at the 104th meeting of the Inter American Tropical Tuna Commission (IATTC) held in Lisbon, Portugal, from August 31 to September 4. The commission manages tuna and other fish stocks and associated ecosystems across the Eastern Pacific Ocean.
The new strategy establishes science-based rules aimed at completing the recovery of Pacific bluefin tuna and maintaining the population over the long term. It also allows for modest increases in catches while providing for automatic reductions if the stock begins to decline again.
“A proposal was adopted … and that’s really great progress,” Dave Gershman, senior officer for international fisheries at The Pew Charitable Trusts, told Mongabay.
Pacific bluefin tuna (Thunnus orientalis) suffered a dramatic population decline due to excessive fishing. By 2016, its population had fallen to just 2.6 per cent of its historic size prompting the IATTC to approve a rebuilding plan the following year.
The population has since recovered substantially.
The latest harvest strategy is intended to ensure that this recovery continues and that management measures are in place before another decline occurs.
“You want to have these things in place when times are good so it’s there when you need it,” Gershman said.
Pacific bluefin tuna is managed jointly across the Pacific because the species forms a single population that moves between the eastern and western parts of the ocean. The IATTC works with the Western and Central Pacific Fisheries Commission (WCPFC) through a joint working group.
The strategy adopted by the IATTC followed three meetings of the joint working group in 2026 and was proposed by Japan, the United States and Mexico.
For the strategy to be effective across the species’ entire range the WCPFC will also need to adopt a complementary harvest strategy for its waters. The commission’s next meeting is scheduled for November 30 to December 4 in Vanuatu.
No agreement on three major tuna species
While the agreement on Pacific bluefin tuna was welcomed as a significant conservation step, IATTC members failed to reach consensus on a proposed management framework for three other commercially important tuna species bigeye, yellowfin and skipjack.
The three species are frequently caught together. The proposed multispecies harvest strategy would have established rules under which signs of decline in one stock could trigger fishing restrictions affecting all three species.
Such a framework would have been a first for tuna fisheries management.
According to IATTC stock assessments, the populations of bigeye, yellowfin and skipjack are currently considered to be in healthy condition. However, industry groups have argued that adopting predictable, science based management rules is important for maintaining confidence in the sustainability of global tuna supplies.
Wetjens Dimmlich, advocacy lead at the Global Tuna Alliance, said the tuna market was increasingly concerned that the IATTC was falling behind other regional fisheries management organisations in adopting modern management tools.
Proposals from the European Union, Ecuador and the United States were not adopted. Under IATTC rules, management measures require consensus among members.
Yellowfin and skipjack dominate catches
Tuna fishing remains a major commercial activity in the IATTC convention area.
Between January and August 2026, vessels caught approximately:
- 314,230 metric tonnes of yellowfin tuna
- 217,807 metric tonnes of skipjack tuna
- 16,330 metric tonnes of bigeye tuna
- 3,928 metric tonnes of Pacific bluefin tuna
The principal fishing fleets include vessels flying the flags of Ecuador, Mexico, Panama, the United States and Venezuela.
Yellowfin, skipjack and bigeye tuna are managed exclusively by the IATTC, while Pacific bluefin tuna is managed jointly with the WCPFC because its population spans the Pacific Ocean.
The meeting also drew criticism from conservation and labour advocates over transparency, illegal fishing and working conditions at sea.
NGOs belonging to the European IUU Fishing Coalition called for stronger measures to combat illegal, unreported and unregulated (IUU) fishing and improve transparency in the fishing industry.
Among their demands was greater disclosure of the beneficial ownership of fishing vessels, which would help identify the individuals and companies ultimately profiting from fishing operations and allow authorities to hold them accountable for violations.
The coalition also called for onboard inspections, stronger labour standards and stricter port controls to prevent illegally caught fish from entering international markets.
However, proposals from Ecuador and Canada on greater transparency and monitoring were not adopted, while discussions on port measures remained at a preliminary stage.
Labour standards were not discussed during the meeting.
Dimmlich said sustainable fisheries management must also address the conditions of workers involved in the industry and criticised the IATTC for lagging behind other regional fisheries management organisations on labour protections.
The agreement on Pacific bluefin tuna nevertheless represents a significant conservation milestone. With the stock having recovered from historically low levels the challenge now is to ensure that increased fishing pressure does not reverse those gains.