By: Max Ackerson
On January 17, 2026, the United Nations High Seas Treaty, formally the Agreement under the United Nations Convention on the Law of the Sea (“UNCLOS”) on the Conservation and Sustainable Use of Marine Biological Diversity of Areas beyond National Jurisdiction and commonly called the BBNJ Agreement (“the Agreement”), entered into force, the culmination of over five years of negotiations followed by a nearly three-year ratification process. The Agreement was adopted on June 19, 2023, by the Intergovernmental Conference on Marine Biodiversity of Areas Beyond National Jurisdiction. The Intergovernmental Conference, led by Singapore’s Ambassador Rena Lee, convened to consider recommendations by the 2017 Preparatory Committee with the goal of negotiating the core elements and finalizing the text of a legally binding instrument under UNCLOS for biodiversity conservation and sustainable use in areas beyond national jurisdiction. After almost a decade, those efforts have finally succeeded.
The Agreement is targeted at protecting biodiversity in areas beyond the reach of national jurisdiction, which the treaty defines as the high seas and the Area. The high seas are the water column outside any country’s exclusive economic zone (“EEZ”), beyond the 200 nautical miles measured from a state’s territorial sea. The Area is the seabed and ocean floor beyond national jurisdiction; UNCLOS treats the Area and its resources as the “common heritage of mankind,” with seabed activities administered through the International Seabed Authority (“ISA”). Together, they cover the vast majority of the ocean, including ecosystems and resources that sit outside any single state’s regulatory reach and are therefore subject to increased risk of exploitation.
Until now, biodiversity protection in areas beyond national jurisdiction has been handled through a set of sector-specific regimes that regulate activities on the high seas without treating biodiversity as the primary object of governance. Shipping impacts are addressed largely through the International Maritime Organization’s framework, including pollution control rules under MARPOL and safety and vessel standards under instruments like SOLAS. High seas fishing is regulated primarily through regional fisheries management organizations, which set catch limits and compliance measures for particular species and regions. Seabed mineral activity in the Area is administered through the ISA under UNCLOS, with its own licensing and regulatory system. The result has been governance that is strongest when an environmental problem fits neatly within a single sector’s mandate, and weakest when biodiversity harm is cumulative, cross-sector, or under no single institutional purview.
Given this patchwork’s inefficiency, the Preparatory Committee concluded that incremental reform through existing sectoral bodies would be insufficient. It therefore recommended that the United Nations General Assembly convene an intergovernmental conference to negotiate a new, legally binding instrument under UNCLOS focused specifically on biodiversity beyond national jurisdiction. That recommendation supplied both the legal mandate and the negotiating agenda that ultimately produced the Agreement.
The Preparatory Committee also helped consolidate the negotiations into a coherent “package” of issues intended to be addressed together. The resulting structure remains visible in the Agreement. It centers on four components that are meant to work in combination rather than in isolation. These components are (1) marine genetic resources and benefit sharing, (2) area-based management tools including marine protected areas, (3) environmental impact assessments, and (4) capacity building through the transfer of marine technology. The decision to treat these as a single package was not merely organizational; it was political. The Agreement’s viability depended on balancing conservation objectives with questions of fairness and implementation capacity across developed and developing states, and across stakeholders with sharply different interests in the high seas—from the mining of critical minerals to fisheries access.
Given that cautious balance, the Agreement is designed to function less like a self-executing rulebook and more like a decision-making framework that produces measures through defined procedures. For marine protected areas and other area-based management tools, proposals are submitted to the Secretariat and must include specific components, such as a geographic description, baseline information on biodiversity and human activities, stated conservation and sustainable-use objectives, and a draft management plan with monitoring and review measures. The Secretariat then makes the proposal public and transmits it to the Scientific and Technical Body for a preliminary completeness review. After that review, the proposal may be revised and resubmitted, reposted publicly, and opened to consultations with interested states, adjacent coastal states, and relevant stakeholders.
The Agreement applies the same procedural architecture across its other pillars. For environmental impact assessments, it requires parties to ensure that planned activities under their jurisdiction or control in areas beyond national jurisdiction are assessed before authorization, and it ties that process to transparency by requiring environmental impact assessment reports and monitoring reports to be made available through the Clearing-House Mechanism, with the Scientific and Technical Body able to provide comments. For marine genetic resources, it builds a traceability system through the Clearing-House Mechanism. Before collection, a party submits notice, which triggers issuance of a standardized “BBNJ” batch identifier. After collection, the party updates the same record with follow-on information, including repository and location details, and links any later utilization information to that same identifier. The result is a continuous reference chain connecting collection to custody and subsequent use, which supports transparency and makes benefit sharing administrable rather than merely aspirational.
While this framework constitutes a historic consensus on the great blue deep, a threshold issue is who is actually bound. The Agreement applies only to states and eligible regional economic integration organizations that have deposited an instrument of ratification, acceptance, approval, or accession, and the UN Treaty Collection tracks those Parties. That matters because the Agreement’s core tools operate primarily through state jurisdiction and control over vessels, nationals, and authorizations. If major flag states or major maritime economies remain outside the treaty, actors can reroute through non-party jurisdictions, weakening compliance incentives even if the treaty’s procedures are well designed. The United States is a particularly important example. The United States signed the Agreement in September 2023 but has not ratified it, so it is not a Party and will have limited formal influence over early implementation decisions, including reporting practices and the design of marine protected areas. However, despite a lack of U.S. Senate approval, the treaty is no longer a small-coalition project. As of entry into force, 85 countries have ratified the Agreement, including China, Japan, South Korea, Mexico, and Brazil, as well as the European Union and a significant number of EU Member States. That breadth matters because it brings major maritime and economic actors inside the Agreement’s reporting, assessment, and implementation architecture, increasing the likelihood that treaty standards will influence behavior through flag-state control, port access, and market expectations even in areas beyond national jurisdiction.
Yet the central constraint remains implementation, not accession. For example, public reporting and NGO analyses have raised recurring concerns about segments of China’s distant-water fleet, including high-intensity fishing activity near EEZ boundaries and the disabling of AIS or other tracking practices that complicate monitoring and enforcement. Even assuming China remains a committed Party, those patterns illustrate the Agreement’s implementation challenge. The treaty’s protected-area designations and biodiversity safeguards will constrain fishing only to the extent China, and other major flag states, translate them into operational controls over vessels and operators under their jurisdiction, investigate evasive behavior, and impose meaningful consequences when conduct undermines conservation objectives. In that sense, the Agreement’s hardest work is not drafting conservation measures, but making them enforceable beyond mere goodwill and strongly worded statements.
In its first year, the Agreement should be evaluated by its early implementation practice, not its aspirations. First, the initial proposals for marine protected areas should be assessed for specificity. Do they identify the particular activities to be managed, articulate measurable objectives, and include monitoring and review requirements that can be implemented in practice? Second, implementation will depend on whether major flag states incorporate those measures into domestic controls over vessels and operators under their jurisdiction, including authorization conditions, compliance monitoring, and meaningful consequences for violations. A protected area that is not enforced against a Party’s own fleet will not materially constrain conduct in areas beyond national jurisdiction.
Third, the environmental impact assessment regime should be evaluated by use, not existence. Are assessments treated as a genuine precondition to authorization for activities under a Party’s jurisdiction or control, and are assessment reports and monitoring updates published in a consistent and accessible manner? Finally, the Clearing-House Mechanism should be evaluated as compliance infrastructure. If notices, reports, and decisions are timely, searchable, and regularly used, they will create a record capable of supporting oversight and pressure through port measures and market expectations. If reporting is inconsistent, the Agreement’s institutional architecture will outpace its practical effect.
The High Seas Treaty’s entry into force is a legal achievement that took the better part of a decade to produce. Whether it amounts to more than that will be visible within the next few years, not in the text of the Agreement, but in whether the Clearing-House Mechanism accumulates a usable record, whether the first marine protected area proposals contain enforceable specifics, and whether major flag states treat their obligations as operational rather than aspirational. The governance gap that made this treaty necessary did not develop because states lacked good intentions. It developed because sector-specific regimes without shared oversight created spaces where harm was everyone’s problem and no one’s responsibility. Closing that gap requires the Agreement to function as the accountability infrastructure it was designed to be, and that is a question of political will, not treaty design.
