Fisheries scientists in “An Evaluation of the Sustainability of Global Tuna Stocks Relative to Marine Stewardship Council Criteria” – a new report commissioned by the International Seafood Sustainability Foundation (ISSF) – found 11 of the 23 major commercial tuna stocks worldwide are avoiding overfishing and maintaining target stock biomass levels when measured against the Marine Stewardship Council (MSC) Fisheries Standard.

In the March 2023 edition of the ISSF report, eight stocks passed Principle 1. In this year’s report, three additional stocks received a passing score.
The 11 stocks are Western Atlantic skipjack, North Atlantic albacore, South Atlantic albacore, Eastern Atlantic bluefin, Western Pacific yellowfin, Western Pacific bigeye, Western Pacific skipjack, Eastern Pacific yellowfin, Eastern Pacific skipjack, Indian Ocean skipjack and Southern Ocean bluefin. These stocks achieved a passing score for the Standard’s Principle 1, “Sustainable Fish Stocks”, which requires fisheries to be managed in a manner that does not lead to overfishing or depletion of exploited fish populations.
Seven of the 23 stocks have also fully implemented well-defined harvest control rules. However, failure to implement controls before rebuilding is required continues to contribute to an increasing number of stocks failing to meet minimum requirements on harvest control rules.
The updated scores in the report focus on stock status (MSC Principle 1) and are based on publicly available fishery data.
MSC Principle 1 states: “A fishery must be conducted in a manner that does not lead to over-fishing or depletion of the exploited populations and, for those populations that are depleted, the fishery must be conducted in a manner that demonstrably leads to their recovery.”
The report authors attribute stocks with failing scores to poor stock status, the lack of well-defined harvest control rules in place and the lack of effective tools to control harvest. In the 2024 report, seven of the 23 stocks have fully implemented well-defined harvest control rules.
Unchanged since last year’s March 2023 version of the report, of nine tuna stocks in the Atlantic Ocean, four received an overall principle-level passing score: Western skipjack, Northern albacore, Southern albacore and Eastern bluefin.
Among nine tuna stocks in the Pacific Ocean, these five received overall principle-level passing scores: Western yellowfin, Western bigeye, Western skipjack, Eastern yellowfin and Eastern skipjack. Western yellowfin and Western bigeye did not receive a principle-level passing score in the March 2023 report.
Of four tuna stocks in the Indian Ocean, as in last year’s report, only skipjack received an overall principle-level passing score.
Southern bluefin received an overall principle-level passing score – a change from last year’s report. This stock is also the second bluefin stock to receive a passing score.
Meanwhile, in the Atlantic, yellowfin, bigeye, Eastern skipjack, Mediterranean albacore and Western bluefin received principle-level failing scores – as also reported last year.
In the Pacific, four stocks—as also reported last year—received overall principle-level failing scores: Eastern bigeye, Northern albacore, Southern albacore and Pacific bluefin. And in the Indian Ocean, as reported last year, yellowfin, bigeye and albacore all received overall principle-level failing scores.
Since 2011, ISSF has been an active stakeholder in MSC tuna fishery assessments and certifications.
ISSF is a global coalition of seafood companies, fisheries experts, scientific and environmental organisations, and the vessel community. It promotes science-based initiatives for long-term tuna conservation, FAD management, bycatch mitigation, marine ecosystem health, capacity management and illegal fishing prevention.