High Seas Treaty (BBNJ): Marine Biodiversity Beyond National Jurisdiction

The High Seas Treaty, known by the acronym BBNJ, is the international agreement on the conservation and sustainable use of marine biological diversity in areas beyond national jurisdiction. It was adopted in New York on 19 June 2023 as an implementing agreement under the United Nations Convention on the Law of the Sea and entered into force on 17 January 2026, when the sixtieth required treaty instrument was deposited. According to the official United Nations Treaty Collection, on 30 June 2026 the agreement had 145 signatories and 90 parties. Brazil signed it on 21 September 2023 and ratified it on 16 December 2025.

Summary

• BBNJ covers areas beyond national jurisdiction: the high seas and the Area, meaning the international seabed and its subsoil.
• The agreement complements the United Nations Convention on the Law of the Sea as another major implementing agreement alongside the Part XI regime and the Fish Stocks Agreement.
• Its four main blocks cover marine genetic resources and digital sequence information, area-based management tools, environmental impact assessments, capacity-building and marine technology transfer.
• The political importance of the treaty lies in turning a zone once governed by broad freedoms and fragmented institutions into a space with common rules, without erasing the powers of sectoral organizations.

What BBNJ Tries To Solve

The starting point of the treaty is simple: most of the ocean belongs to no state, while remaining politically active. Navigation and cables form the infrastructure. Scientific research, fishing and bioprospecting form the economic and knowledge layer. All of these practices depend on rules about who may act, who must assess risks and who receives benefits. The United Nations Convention on the Law of the Sea already separates coastal zones from international spaces and gives distinct regimes to the high seas and the Area. It was negotiated before today’s techniques could turn deep-sea genetic material into data, knowledge and products.

That gap matters because marine biodiversity beyond national jurisdiction involves concrete ecosystems and genetic material with scientific value. Deep-sea organisms can interest basic science and sectors such as pharmaceuticals, cosmetics and biotechnology. States with more capital, laboratories, research vessels and data-processing capacity can turn those resources into knowledge and economic value far more easily than developing countries can. Without rules on access, information and benefit-sharing, freedom of research could produce a practical concentration of gains.

The treaty also responds to an institutional problem: high-seas governance is fragmented by sector. Rules on navigation and fishing coexist with regimes for pollution, cables, security and deep-seabed mining. Regional fisheries bodies deal with particular stocks. The International Maritime Organization regulates aspects of navigation and vessel-source pollution. The International Seabed Authority deals with mineral resources in the Area. BBNJ creates a general layer for biodiversity and preserves the role of existing instruments and bodies. That balance explains much of the text’s careful wording.

High Seas, the Area and National Jurisdiction

In the law of the sea, the expression "areas beyond national jurisdiction" has a precise technical meaning. It refers to spaces outside the zones where coastal states exercise sovereignty or sovereign rights. The exclusive economic zone normally extends up to 200 nautical miles from baselines. The continental shelf may extend beyond that when geology allows it. Coastal-state rights over the shelf concern the seabed and subsoil, rather than the water column. Beyond those limits lie two distinct legal realities. The high seas are connected with freedoms of navigation, fishing, research and cables. The Area has a mineral regime treated as the common heritage of humankind.

This distinction was one of the hardest points in the negotiations. Mineral resources in the Area were already administered through an internationalized logic. By contrast, some states could read living and genetic resources of the high seas as part of the freedom of the seas. Others, especially developing countries, argued that the common-heritage logic should at least inform benefit-sharing. The final agreement manages that debate by bringing together freedom of marine scientific research, fair benefit-sharing and protection of the marine environment. Cooperation, precaution and attention to developing-country needs complete that formula.

The practical consequence is that BBNJ preserves the architecture of UNCLOS and places biodiversity beyond national jurisdiction under common procedures. The treaty builds duties of information, reporting, institutional mechanisms and channels of cooperation. Instead of replacing the architecture of UNCLOS, it tries to correct its blind spots.

Genetic Resources and Digital Information

The most sensitive block of the agreement deals with marine genetic resources and their circulation as information. These resources include biological material with actual or potential value. The current debate, however, goes beyond physical collection. Much research depends on digital sequence information. A sample collected by a vessel can be analyzed, deposited in a database, compared with other datasets and used by researchers who never touched the original organism. For that reason, the discussion about benefits could not remain limited to the actor that removed a sample from the sea.

The official agreement text creates duties of notification, transparency and information-sharing. The idea is to allow states and institutions to track activities involving marine genetic resources of areas beyond national jurisdiction. The treaty provides for monetary benefits and turns non-monetary benefits into channels for scientific participation. Those channels include access to samples and data, training, institutional cooperation and marine technology transfer.

This point makes BBNJ an environmental treaty and a scientific-capacity treaty at the same time. A country may have a strong interest in conserving the oceans and still lack the infrastructure behind advanced ocean research. Vessels, laboratories, trained personnel and databases are part of that bottleneck. Without capacity-building, the promise of universal participation becomes a formality. The agreement tries to reduce that distance, although its effectiveness will depend on finance, support institutions and the willingness of more capable states to share knowledge in concrete ways.

Protected Areas and Impact Assessment

Another BBNJ axis is the creation of area-based management tools, including marine protected areas. This instrument is central to connecting the treaty with the political goal of protecting 30% of the ocean by 2030. Before BBNJ, it was difficult to establish broad protected areas on the high seas through a global process. Specific sectors could create their own restrictions, but there was no general mechanism able to assess ecological vulnerability together with sustainable use.

Under the new model, proposals for protected areas can be examined by the agreement’s scientific and political bodies. Conflicts between economic uses, research, infrastructure and environmental protection will continue. The innovation is to give those conflicts a common procedure. A high-seas protected area will matter only if it has clear objectives, applicable measures, monitoring and some form of implementation. The treaty is therefore strongest as a decision-making platform.

Environmental impact assessments form the third pillar. Before authorizing or carrying out an activity with significant effects, BBNJ requires risk assessment, information-sharing and consideration of alternatives. On the high seas, this obligation has a special dimension: damage there can affect shared ecological systems and migratory species in spaces without direct coastal authority. BBNJ seeks to standardize when an assessment must occur, what information must be produced and how results must be communicated.

Institutions of the Agreement

BBNJ creates an institutional architecture centered on the Conference of the Parties and a scientific and technical body. From that center, the regime organizes benefit-sharing, implementation, capacity-building, technology support and a secretariat. This architecture is typical of modern environmental regimes: the treaty establishes principles and procedures, while much of its concrete content will be developed through later decisions. The first Conference of the Parties must take place no later than one year after the agreement’s entry into force, which makes 2026 and early 2027 decisive for implementation.

This institutional phase is less visible than treaty adoption, yet it may be more important. The COP will have to detail procedures for proposals, data and reporting. It must decide financing, committees, observer accreditation and relations with other organizations. The agenda also includes disputes over the seat of the secretariat, scientific priorities and forms of support for countries with lower capacity. A treaty can enter into force with many signatures and still take years to produce material changes at sea. The difference between diplomatic symbol and effective regime will lie in those decisions.

The wider context reinforces that urgency. BBNJ is connected to SDG 14, the United Nations Ocean Conferences and the UN Decade of Ocean Science for Sustainable Development. The 2017 conference already called for a binding instrument under UNCLOS for biodiversity beyond national jurisdiction. The 2022 conference highlighted insufficient ocean finance and marine technology. The 2025 conference in Nice kept political pressure on ratification and implementation. The agreement is now in force, but its promise depends on turning commitments into operational capacity.

Brazil, CLAM and Developing Countries

For Brazil, BBNJ connects the law of the sea with environmental policy, ocean science and development diplomacy. Brazil has an extensive coastline, participates in UNCLOS and has interests related to continental shelf and biodiversity. In the negotiations, it sought to act through the Core Latin American Group, or CLAM. That group brought together Latin American countries that presented common positions and engaged with the G77+China, Caribbean islands and African countries. The point was to prevent governance of genetic resources beyond national jurisdiction from being limited to those who already had technology.

Brazil’s position tried to bring two legal vocabularies closer together: the common heritage of humankind and freedom of marine scientific research. In the final hours of negotiation, Brazil and Jamaica helped build a compromise formula that allowed both to remain in the text. That solution is not trivial. Exclusive emphasis on common heritage could have worried countries with strong scientific sectors. Exclusive emphasis on scientific freedom could have looked like a license for technological appropriation. The combination creates tension and, at the same time, makes cooperation possible.

Brazil’s interpretative declaration upon ratification confirms another point: Brazil understands that BBNJ must be applied in accordance with UNCLOS. For Brasilia, the new governance layer does not alter sovereign rights, jurisdiction or coastal-state powers, especially regarding the continental shelf. This position is consistent with the concern that the biodiversity regime beyond national jurisdiction should not weaken existing rules or enter areas under coastal-state rights.

Limits and Political Disputes

The treaty has a defined scope and should be read as a coordinating instrument rather than a complete ocean constitution. Fishing remains strongly linked to regional organizations and specific instruments. Deep-seabed mining remains under the International Seabed Authority and within an intense political dispute. Plastic pollution, acidification, warming and underwater noise have causes that go far beyond BBNJ. Even in protected areas, decisions will have to coexist with activities already regulated by other bodies.

Implementation creates another test. The high seas are vast, expensive to monitor and technically difficult to police. Satellites, vessel-identification systems, scientific databases and cooperation among authorities can help. These instruments by themselves do not replace political will. The experience of maritime disputes, such as those in the South China Sea, shows that legal rules can coexist with strategic competition. BBNJ will be more effective when its procedures are adopted by governments, scientific communities and sectoral organizations.

Even so, the change is significant. Until recently, governance of biodiversity in areas beyond national jurisdiction was a long diplomatic project, sustained by preparatory steps and intergovernmental conferences. Now the task is institutional: parties must organize the COP and build the regime’s organs. The ocean has not become easier to govern. High-seas biodiversity now has its own regime, moving beyond old dependence on scattered freedoms and sectoral norms.

Why the Treaty Matters

The value of BBNJ lies in connecting conservation, science and equity. Conservation enters because areas beyond national jurisdiction contain vulnerable ecosystems connected with the rest of the planet. Science enters through dependence on research, data and technologies that few countries fully control. Equity appears when the benefits of marine biodiversity need to circulate beyond the actors able to reach it first.

Its institutional value appears in the reinforcement of the United Nations as a negotiating forum for common goods and transboundary problems. The agreement handles rivalries, asymmetries and economic conflicts through an institutional grammar. Governance no longer turns only on access to the open sea. It now requires transparency, risk assessment, benefit-sharing and scientific participation.

That is the real shift produced by the High Seas Treaty. Freedom of the seas remains an essential part of international law. In the twenty-first century, freedom without cooperation can turn openness into knowledge concentration and environmental harm. BBNJ tries to preserve the open space of the ocean while creating common duties to protect it. Its success will depend less on the elegance of the text and more on the parties’ ability to fund science, accept transparency and turn the COP into a real center of ocean governance.