The ISSF commissioned two recent reports on the status of global tuna stocks. The Status of the World Fisheries for Tuna report found that the vast majority of tuna is caught from healthy, abundant tuna stocks. The other report, An Evaluation of the Sustainability of Global Tuna Stocks Relative to Marine Stewardship Council Criteria, found that only eight out of twenty-three major commercial tuna stocks worldwide are successfully avoiding overfishing and maintaining target stock biomass levels when measured against Version 2 of the Marine Stewardship Council (MSC) Fisheries Standard.
Both reports assessed the same twenty-three major commercial tuna stocks: four albacore fisheries, four bigeye fisheries, four bluefin fisheries, five skipjack fisheries, and four yellowfin fisheries. The authors considered the most recent scientific assessments and management measures from relevant regional fishery management organizations (RFMOs). All ISSF “Status of Stocks” focus on abundance, exploitation/management, and environmental impacts like bycatch to formulate a fishery rating.
The Status of the World Fisheries for Tuna report found that 85 percent of global commercial tuna catch was sourced from stocks with “healthy” levels of abundance in 2021. 85 percent is slightly down from 86.4 percent seen in July 2022, but consistent with most measurements since 2011. The percentage of tuna harvested from stocks with healthy abundance has been 70 percent or higher since 2011, see Figure 1.
61 percent of global tuna stocks have healthy abundance, independent of catch. That ratio has also been consistent since 2011 (Figure 2).
15 percent of global commercial tuna catch is coming from stocks not considered “healthy.” ISSF determined that 11 percent of that 15 percent comes from overfished stocks in need of stronger management. This is slightly greater than the 9.2 percent found in 2022. The report highlighted tuna fisheries that are still overfished and subjected to overfishing, including Mediterranean albacore, Indian Ocean bigeye, and yellowfin. Pacific Ocean bluefin is overfished but not subject to overfishing at this time.
The new MSC standard
The other report, An Evaluation of the Sustainability of Global Tuna Stocks Relative to Marine Stewardship Council Criteria, found that only eight of the 23 avoided overfishing and maintained biomass to meet Version 2 of the MSC standard. Most tuna fisheries are still struggling to implement harvest control rules. Six of the 23 fisheries assessed had fully implemented, and well-defined harvest control rules, but “failure to implement controls before rebuilding is required has led to an increasing number of stocks failing to meet minimum requirements on harvest control rules.”
Version 3 raises the bar even higher for harvest control rules, such that fisheries managed by RFMOs will be expected to deliver “state of the art” harvest strategies. “These management measures are essential to ensuring the long-term sustainability of shared tuna stocks by providing a pre-agreed harvest objective and a ‘safety net’ to reduce catch if stocks begin to decline. Agreement on harvest strategies has been notoriously difficult to achieve, requiring alignment between multiple states representing their own national interests.” It is likely that fewer than eight of the 23 global tuna fisheries would perform as well to Version 3 of the MSC standard.
These management measures are essential to ensuring the long-term sustainability of shared tuna stocks by providing a pre-agreed harvest objective and a ‘safety net’ to reduce catch if stocks begin to decline. Agreement on harvest strategies has been notoriously difficult to achieve, requiring alignment between multiple states representing their own national interests.
It is likely that fewer than eight of the 23 global tuna fisheries would meet Version 3 of the MSC standard.
Conservation organizations believe tuna is doing poorly
A third report on the status of global tuna stocks was published by Greenpeace in February. The 2023 High Cost of Cheap Tuna rated the top North American grocery retailers in their sourcing policies for tuna. The rubric was predictably strict, and Greenpeace failed all 16 retailers on their human rights policies. But there were some reported improvements since 2021 and even passing grades for environmental sustainability criteria, though overall, all retailers failed or got a “D.”
The juxtaposition of these three reports, ranging from very positive to overwhelmingly negative, illustrates the incredible range of perspectives on global tuna sustainability. All have an essential role in driving tuna demand.
