High Seas Treaty: How fish has emerged as the bone of contention among countries

In 2023, the United Nations adopted a new global agreement called the Biodiversity Beyond National Jurisdiction (BBNJ) Treaty. Also known as the High Seas Treaty, it aims to protect marine biodiversity in parts of the ocean that do not belong to any country called the High Seas.

These areas cover over two-thirds of the world’s oceans and are home to species that help maintain the planet’s climate and ecological balance. But existing international ocean laws have not been strong enough to stop overfishing, pollution and biodiversity loss. The new treaty tries to fill that gap.

The BBNJ treaty promises to: Conserve marine biodiversity, share benefits from marine genetic resources (MGR), create marine protected areas (MPA), require environmental impact assessments and support developing countries with money, training and technology.

But while the treaty aimed to protect marine life, there was one big problem: Fish were excluded.

From the early stages of the treaty talks, countries had already agreed not to include fishing. Fish would continue to be managed by other groups, not the BBNJ treaty.

But this raised a serious question: How can we protect ocean biodiversity and leave out fish, one of the most important parts of it?

To understand how this decision was made, a team of researchers from the University of Oldenburg in Germany and the University of Oxford in the United Kingdom studied the treaty process in detail.

Between 2018 and 2024, the researchers:

• Attended key UN treaty meetings, especially Intergovernmental Conference (IGC)-4 (2022) and IGC-5 (2023)

• Interviewed 38 people, including government delegates, fisheries managers, environmental NGO and scientists

• Analysed official speeches and documents from countries

• Asked delegates two main questions:

  1. Do you consider fish a part of marine biodiversity?

  2. Should fish be included in the BBNJ treaty?

They found that countries were deeply divided. Some said fish are biodiversity and should be protected. Others said fish are already managed under separate fishing rules and BBNJ should not interfere.

The biggest fight was over fishing rights. For Small Island Developing States (SIDS), fish are more than just biodiversity, they are a source of food, jobs and culture. These countries feared losing control over their fish. “Our fish are not your marine biodiversity,” said one pacific delegate in 2022.

Fish in the High Seas are currently managed by groups called Regional Fisheries Management Organizations (RFMO). Some of them are: Western and Central Pacific Fisheries Commission (WCPFC), Inter-American Tropical Tuna Commission (IATTC) and Northwest Atlantic Fisheries Organisation (NAFO).

These groups set rules about how much fish can be caught, where and by whom, mostly for big species like tuna.

During the treaty talks, wealthy countries like the United States, Canada, EU, Japan and South Korea insisted that BBNJ should not interfere with the work of RFMOs. They said adding new rules would cause confusion.

So in the final treaty, most fishing activities were excluded except when fish are used for scientific research or genetic study.

But many scientists considered this a big problem. Fish are a key part of ocean biodiversity and leaving them out creates a major gap in protection.

Another big issue was whether fish should be seen as Marine Genetic Resources (MGR) used in science, medicine or industry. If fish are treated as MGRs, then profits or research data from using them must be shared fairly, especially with developing countries.

But rich countries like the US, Canada and the EU strongly resisted this. They said it would slow down innovation and add more rules.

On the other hand, Pacific Small Island Developing States (PSIDS) were worried. They said rich countries have laboratories, ships and technology to collect marine genes, while poorer countries do not. “The moment fish enter the picture as genetic resources; everything becomes politically charged,” said a PSID delegate in 2023

A 2018 study in Science Advances found:

• Just 10 institutions held 47 per cent of all patents on marine genetic material

• Most were from the US, Germany and Japan

• One German company BASF held nearly half of all marine patents

“Without labs or ships, how can we benefit from our biodiversity? The law must give us more than words,” said another delegate.

The treaty allows countries to create MPAs in the High Seas zones, where activities like fishing or mining are limited to protect ecosystems.

But there were different opinions on how strict these zones should be.

• The European Union and environmental groups wanted strong “no-take” zones where no fishing is allowed

• Countries like Iceland and many SIDS were worried. They said strict MPAs could affect their traditional fishing grounds and hurt their economies

Climate change is already making things worse for island nations. As ocean temperatures rise, fish are moving away from warm tropical waters to cooler areas. This means SIDS are losing access to the fish they rely on.

A 2022 study in Nature Communications warns that tropical countries could lose up to 40 per cent of their fish catch by mid-century.

Now, with the new treaty, SIDS fear that new fishing rules or control by powerful countries could take away even more of their rights.

Another big question was: Who gets to decide what happens in the High Seas?

Coastal countries, especially SIDS, said that activities in international waters directly affect their ecosystems and people. Fish like tuna migrate between national waters and the High Seas.

A delegate from Palau said, “The High Seas are a shared heritage. For SIDS like ours, they are more than an economic resource, they are our identity.”

But landlocked countries disagreed. They said the High Seas belong to everyone, not just countries with coastlines, and all countries should have equal rights to access and benefit.

The BBNJ treaty is an important step for protecting the ocean. But the exclusion of fish, especially in a treaty meant to protect marine biodiversity, shows how divided the world still is on questions of conservation, fairness and power.

This study helps us understand why fish were left out, how global politics shaped the outcome, and why poorer nations are still demanding ocean justice.

The final BBNJ treaty excludes fishing from its core rules, unless fish are being used for genetic research or environmental assessments.

While fish are biologically part of marine biodiversity, they are legally left out of most protections under the BBNJ Agreement.

This has created a major gap, and the researchers say that future work must reconnect conservation and fisheries and make sure that developing countries have real access, voice and benefits in ocean governance.

Final summary: The 2023 High Seas Treaty aims to protect marine biodiversity beyond national borders but excludes fish, sparking global debate. Wealthy nations upheld existing fishing rules, while developing countries feared losing rights. This exclusion creates a major protection gap, revealing deep divisions over conservation, equity and control of ocean resources.