By: Casey Galvin
On January 17, 2026, the Agreement under the United Nations (UN) Convention on the Law of the Sea on the Conservation and Sustainable Use of Marine Biological Diversity of Areas Beyond National Jurisdiction, commonly known as the BBNJ Agreement or High Seas Treaty, entered into force. Its entry into force marks the culmination of a long and deliberate effort by the international community to address persistent gaps in governance affecting the majority of the ocean that lies beyond national jurisdiction. For the first time, international law provides a comprehensive, legally binding framework dedicated specifically to the conservation and sustainable use of marine biodiversity in areas beyond the reach of any single state.
Under international law, the “high seas” refers to “all parts of the ocean that aren’t included in the exclusive economic zone, the territorial sea, or the internal waters of a country . . . .” Generally, this includes ocean areas beyond 200 nautical miles from a coastal state. These vast areas account for nearly half of the Earth’s surface and two-thirds of the ocean, yet they have long existed in a regulatory blind spot. While the high seas have been governed “patchwork-style” through mechanisms such as regional fisheries agreements and shipping conventions, they have historically lacked a comprehensive legal regime dedicated to biodiversity conservation. As a result, not even 1% of the high seas has been established as marine protected areas (MPAs).
The importance of protecting the high seas cannot be overstated. The high seas play a critical role in regulating the global climate, supporting marine biodiversity, and sustaining fisheries that billions of people depend on for food security and livelihoods. These areas “are also home to unique ecosystems . . . and migratory routes for whales, tuna, sharks, and seabirds.” At the same time, these areas are increasingly targeted for activities such as industrial fishing, deep-sea mining, and the extraction of marine genetic resources for commercial use. Without a unified governance framework, such activities risk causing irreversible damage to ecosystems that transcend national boundaries and to oceanic processes essential to sustaining life on Earth.
The effort to address this deficiency in protection took a decisive step forward in December 2017, when the UN General Assembly adopted Resolution 72/249. This Resolution’s purpose was “to convene an intergovernmental conference and undertake formal negotiations for a new international legally binding instrument (ILBI or treaty) under the UN Convention on the Law of the Sea (UNCLOS) for the conservation and sustainable development of marine biological diversity in areas beyond national jurisdiction.” Extensive negotiations followed over the next five years, ultimately culminating in an agreement reached by the world’s governments on March 4, 2023. Although agreement on the text represented a significant milestone, the High Seas Treaty could not become operative until it satisfied its ratification requirements. The BBNJ Agreement reached its required sixty ratifications in September 2025, when Morocco became the sixtieth state to ratify it. This triggered the BBNJ Agreement’s entry into force this past month, 120 days later. As of today, the Agreement has been ratified by eighty-five states, with an additional 145 states having signed it. Although signature alone does not create binding legal obligations, it signals support for the Agreement’s objectives and an intention to comply with its provisions in good faith.
The BBNJ Agreement focuses on four interrelated pillars: “[m]arine genetic resources, including the fair and equitable sharing of benefits; [m]easures such as area-based management tools, including marine protected areas; [e]nvironmental impact assessments; and [c]apacity-building and the transfer of marine technology.”
The first pillar focuses on marine genetic resources, which the BBNJ Agreement defines as “any material of marine plant, animal, microbial or other origin containing functional units of heredity of actual or potential value.” This section was among the most contested aspects of the negotiations. Advances in biotechnology have made marine genetic material increasingly valuable for pharmaceutical, cosmetic, and industrial applications. Prior to the Agreement, access to these resources was largely unregulated on the high seas, raising concerns that technologically advanced states and private actors would disproportionately benefit from resources found in areas beyond national jurisdiction. The Agreement responds to this concern by affirming that marine genetic resources of the high seas are not subject to national appropriation and by establishing mechanisms for benefit-sharing that include both monetary and non-monetary benefits, such as access to scientific data and transfer of technology.
The second pillar focuses on area-based management tools (ABMTs), which the BBNJ Agreement defines as “tool[s], including [MPAs], for a geographically defined area through which one or several sectors or activities are managed with the aim of achieving particular conservation and sustainable use objectives . . . .” Prior to the Agreement, some international bodies were able to adopt measures that functioned as ABMTs; however, these measures operated in a fragmented, sector-specific manner and did not “allow for the designation of MPAs that manage activities in a holistic manner and bind states globally.” As a result, no single mechanism existed that was capable of protecting a high seas area from the full range of human activities that threaten it. Under the Agreement, the Conference of the Parties can establish ABMTs, including MPAs, based on scientific criteria, while remaining obligated to respect the competencies of existing international organizations and frameworks with regulatory authority over specific activities.
The third pillar concerns environmental impact assessments (EIAs), which aim to address the environmental risks associated with activities conducted on the high seas. While international law has long recognized a general obligation to “protect and preserve the marine environment,” it has historically provided limited procedural guidance for evaluating environmental impacts that a state’s activities may have beyond its jurisdiction. The BBNJ Agreement responds to this gap by requiring states to conduct EIAs for proposed activities that may have significant adverse effects on the marine environment on the high seas.
The fourth pillar addresses capacity-building and the transfer of marine technology, reflecting the BBNJ Agreement’s emphasis on equity and inclusive participation of all states. This section was the “least controversial” aspect of the negotiations. Many states, particularly developing states, geographically disadvantaged states, and small island states, lack the scientific, technical, and financial capacity necessary to engage meaningfully in high seas research, monitoring, and conservation. The Agreement seeks to reduce these disparities by promoting cooperation, training, and access to marine technology. By strengthening capacity across states, these provisions aim to ensure that all states are able to contribute to and benefit from the conservation and sustainable use of marine biodiversity beyond national jurisdiction.
Despite its significance, the effectiveness of the BBNJ Agreement is not guaranteed, and its entry into force marks only the beginning of a complex implementation process. Most notably, the High Seas Treaty’s obligations apply only to states that have ratified it, and several major states, including the United States, which has signed but not ratified the Treaty, have yet to do so. As a result, activities conducted by non-party states on the high seas remain outside the Treaty’s binding framework, limiting its ability to achieve truly global protection.
Much of the BBNJ Agreement’s ultimate impact will depend on the development of effective institutional and governance structures. To that end, the BBNJ Preparatory Commission is actively developing the Agreement’s operational framework, including its bodies and decision-making processes, in preparation for the first Conference of the Parties, which is scheduled to take place no later than one year from when the Agreement entered into force. Whether these efforts succeed in producing a strong and coherent governance architecture will be critical in determining if the BBNJ Agreement evolves from a landmark legal instrument into a fully functioning regime capable of effectively conserving and sustainably using marine biodiversity on the high seas.
