Reeling in Responsibility: The Path to Sustainable Tuna Fisheries

Even if there are plenty of fish in the sea, tuna reigns supreme. Supporting millions of jobs and a multi-billion dollar market, we eat it in everything from delicate makizushi rolls to tuna fish sandwiches. Besides its outsized role in our lives, tuna is literally a behemoth, with some species rivaling the weight of a small car. 

Unfortunately, overfishing has increased since the 1970s and nearly 38 percent of global fishery stocks are unsustainably harvested, according to a 2024 United Nations report. Tuna is no exception. Certain stocks, or populations, of yellowfin, albacore and bluefin tuna declined steeply over the past decades. Several species were even listed as threatened on the International Union for the Conservation of Nature’s Red List, which tracks species’ conservation status.

But in a rare case of environmental good news, many tuna stocks bounced back. For example, 87 percent of the total tuna catch comes from healthy stocks, and 65 percent of the stocks are at a healthy level of abundance. Plus, the majority of tuna species are no longer considered threatened. 

That update comes from the International Seafood Sustainability Foundation’s Status of the Stocks report, which tracks changes in the 23 major commercial tuna species worldwide. Released several times per year, the overview checks the pulse of the tuna industry at large. The foundation also works to ensure sustainable tuna fishing outside of these reports, so you can enjoy those tasty ahi tuna poke bowls long into the future.

Stock watch

Used by scientists, management organizations, decision-makers and the media, the Status of the Stocks report rates each fish population according to abundance and fishing mortality. It also provides an interactive tool that shows stock health and catch. 

Besides the good news on healthy tuna stocks, the latest report highlighted another positive shift: a decline in overfishing. Since 2024, unsustainable tuna fishing decreased by 8 percentage points. That’s largely due to an improvement in the status of yellowfin tuna in the Indian Ocean, said Victor Restrepo, vice president of science and Scientific Advisory Committee chair at the International Seafood Sustainability Foundation. 

Yellowfin tuna is an important commercial species, making up 31 percent of the overall tuna catch. With improved management, the yellowfin tuna population in the Indian Ocean no longer faces overfishing, Restrepo said.

“Since 2018, the catches have been going down generally — more so for some fishing gear than for others — but overall the catches are going down in response to management,” Restrepo said. “There were also changes to the methodology used for the stock assessment … but also real responses to management in terms of lowering catches.”

This is thanks to some tough choices by the Regional Fisheries Management Organizations — five management organizations that oversee tuna fishing in different parts of the world. Fisheries management can include efforts like implementing annual catch limits, developing prevention and reporting protocols for lost or abandoned gear, and mandating the use of fishing devices that are less harmful to the environment and less likely to unintentionally entangle other species.

Indian Ocean yellowfin catches have declined by nearly 14 percent from 2018 to 2023. But given that some estimates show the Indian Ocean stock declined by over 70 percent from 1950 to 2020, some organizations emphasized the importance of these ongoing sustainability efforts.

“The management bodies have been better at agreeing on management measures that are necessary when the stocks are overfished,” Restrepo said. “Those are always difficult decisions because they are made by consensus generally ... They have been better at reaching consensus for measures that are sometimes painful for the industry, but they are necessary.”

Yet, since the Regional Fisheries Management Organizations are intergovernmental bodies, they don’t respond as quickly as a single country, which can slow the adoption of management strategies, Restrepo said.

Smarter fishing

For its part, the International Seafood Sustainability Foundation takes action on multiple fronts to promote eco-friendly tuna. It’s made fish aggregating devices —  raft-like structures with submerged webbing designed to attract fish — more sustainable. 

“A lot of our work is on improving the fish aggregating device fisheries globally,” Restrepo said. “Because the sailors that use them make the majority of the tuna catch worldwide.”

These devices improve fishing efficiency, but can also entangle marine animals and pollute marine ecosystems. Fortunately, the foundation created a version of this device that’s biodegradable and non-entangling. 

The foundation also works to reduce bycatch — when tuna fishers accidentally capture animals like sharks, sea turtles, rays and seabirds — in other areas. To address this issue, it has held hundreds of workshops to educate skippers about bycatch mitigation, Restrepo said. The organization also conducts bycatch research, provides guidance on best practices, and develops mitigation equipment and techniques. And it’s designing a device to release rays, including giant manta rays, if captured aboard tuna vessels.

Additionally, the foundation directly advocates for tuna stocks. “When a stock is being overfished, we advocate to all of the countries that are members of that Commission to take action quickly to remedy the situation,” Restrepo said. “We also advocate for instruments of management that are that are modern and necessary, like the harvest strategies or management procedures. We try to make sure that the Regional Fisheries Management Organizations put this in place and that the management procedures are, in a way, on autopilot. If a stock goes below a certain threshold, then certain pre-agreed actions will come into place without needing that consensus.”

But it’s not all smooth sailing, and one challenge the foundation faces is misinformation about tuna fishing. Nonetheless, it’s combating that, too. 

“We try to work very hard on that, and we produce a lot of reports to put the truth on the table, so to speak,” Restrepo said. “If something isn't known, we work to find out what's going on, to fill in the gaps.”

Tuna is one of the most widely consumed fish in the world, with a market valued at $41 billion in 2023. But besides its role on our dinner tables, tuna plays a crucial role in marine ecosystems as both predators and prey.
It follows that working to ensure healthy tuna populations benefits both us and the environment. Yet like many environmental issues, it often requires a multi-pronged approach.

“There are many, many aspects to everything that we work on,” Restrepo said. “Very often you may hear in the news about the magic silver bullet solution that somebody's proposing for something, but single-bullet solutions are never that perfect. Fisheries management just requires work on many, many different fronts, and that's the main challenge. But I also find it exciting.”