What We Do

Tuna & High Seas Fisheries

Tuna and other high seas fisheries are some of the most important but challenging fisheries to sustainably manage.


A sustainable future for tuna and other high seas fisheries rests on our ability to change the way we fish and manage these resources.

According to the FAO, over 7.9 million tonnes of tuna and tuna-like species were caught in 2018 — a staggering growth in catches from the 1950s when fewer than 0.6 million tons of tuna were caught. Principal market tuna species — albacore, bigeye, bluefin (three species), skipjack and yellowfin — accounted for about 70 percent of the tuna caught, the majority of which was harvested from the Pacific. Skipjack, the most plentiful and productive principal market tuna, accounts for about 66 percent of principal tuna catch, followed by yellowfin and bigeye (about 25 and 10 percent, respectively).

Tuna fisheries management takes place via multinational cooperation delivered through treaty systems RFMOs. While these systems can potentially be effective at defining policy, their member countries often lack the ability to implement or ensure compliance at local, national, and ocean levels, putting tuna resources at risk. As such, the recent growth in tuna catch hasn’t been matched by improved management — among the seven principal commercial tuna species, about 40 percent of stocks were estimated to be fished at biologically unsustainable levels, and among all the five tuna Regional Fisheries Management Bodies (RFMOs), only one has a robust science-based Harvest Strategy in place.

What is a RFMO?

A RFMO is an international body made up of member countries that share a practical and/or financial interest in managing fisheries and conserving fish stocks in a particular region. RFMOs are established by international agreements or treaties and can take different forms. Some focus on regulating fishing for a particular species or group of species. Others have a broader mandate, with responsibility to ensure that the members’ fisheries do not negatively affect the wider marine ecosystem and the species within it. RFMOs face substantial challenges in their management of stocks and non-target species, such as decision-making inertia, including a lack of political commitment and comprehensive compliance by members.

We are working with the world's largest tuna companies and leading tuna stakeholders globally to transform tuna and high seas fishing.

We do this through developing and implementing projects using new tools and technologies which reduce environmental impact, improve catching sector accountability and support the transition to best practice, science-based management strategies.

Our partnerships with some of the world's largest tuna companies, on the ground capacity in core Northeast Asian tuna producing regions and a team of experienced fishery scientists uniquely positions Ocean Outcomes to effectively drive forward grassroots projects from the bottom-up, connecting that work with top-down investments in reform. Our expanding portfolio of tuna work has already brought a significant percentage of longline tuna vessels into projects working towards improved practices for the first time.

Despite the challenges facing tuna and high seas fisheries, positive transformation is gaining momentum, especially in canned tuna fisheries (which primarily target skipjack and albacore tunas). This includes the adoption of improved management strategies through Harvest Control Rules, collaborative work through programs such as the United Nation Food and Agriculture Organization’s Areas Beyond National Jurisdiction program which trains local tuna managers on best practices, and a growing consumer awareness regarding the critically endangered status of select tuna populations.

NGO Tuna Forum

Ocean Outcomes is a contributing member of the NGO Tuna Forum. The Forum brings together NGOs and others that work comprehensively on global tuna sustainability issues that fall within one or more of the following core focus areas: RFMO Management and Advocacy; Market-based Mechanisms for Improving Sustainability; and, On the Water Research, Activities and Improvements.

Tuna and High Seas Fisheries Fishery Improvement Projects:

Stories from the Field: Tuna and High Seas Fisheries

Meet O2's Tuna and High Seas Fisheries Expert

Daniel’s 20 years of experience in fisheries and marine conservation is driven by a passion for fisheries, the ocean, and marine life. He has become an expert in tuna and sustainable market tools that drive change in fisheries and seafood supply chains. At O2 he is responsible for expanding O2’s portfolio of work, including tuna. Prior to O2, Daniel spent six years at World Wide Fund for Nature’s (WWF) global fisheries initiative (Smart Fishing Initiative), most recently as Deputy Leader. There he lead WWF global engagement in tuna fisheries and provided strategic direction to WWF International on seafood engagement. His past experience also includes a role as Senior Fisheries Certification Manager for the Marine Stewardship Council. Daniel holds a B.Sc in Biology from the University of London and an M.Sc. in Conservation from University College London. He is a keen climber and hiker, and enjoys getting out into the wild as much as he can.