High Seas Treaty Becomes International Law

The High Seas Treaty, formally known as the Agreement under the United Nations Convention on the Law of the Sea on the Conservation and Sustainable Use of Marine Biological Diversity of Areas beyond National Jurisdiction, reached a historic milestone on September 19, 2025. With Morocco becoming the 60th country to ratify the agreement, the treaty will officially enter into force in January 2026, 120 days after this threshold was met. This marks the culmination of nearly two decades of negotiations and advocacy aimed at closing critical regulatory gaps in the governance of international waters.

What the Treaty Means for Ocean Governance

The High Seas Treaty is the first legally binding international agreement dedicated to the conservation and sustainable use of marine biodiversity in areas beyond national jurisdiction, which comprise roughly two-thirds of the world’s oceans. Until now, these vast regions were governed by a patchwork of regional and sectoral agreements, leaving most of the high seas effectively unregulated and vulnerable to overfishing, pollution, and emerging threats such as deep-sea mining. The treaty introduces a comprehensive framework to establish marine protected areas, require environmental impact assessments for high-seas activities, and ensure the fair and equitable sharing of benefits derived from marine genetic resources.

The treaty’s four core pillars include the creation of area-based management tools such as marine protected areas, rules for sharing benefits from marine genetic resources, capacity building and technology transfer for developing countries, and mandatory environmental impact assessments for activities in international waters. These measures are designed to help achieve global biodiversity targets, including the goal of protecting 30% of the world’s oceans by 2030.

The Road to Ratification and Next Steps

The journey to this point has been long and complex. Initial discussions began in the early 2000s, with formal negotiations under the United Nations starting in 2017. The final text was agreed upon in March 2023 and adopted by 193 UN member states in June 2023. Ratification by 60 countries was required for the treaty to enter into force, a milestone reached at the United Nations Ocean Conference in Nice, France, where a surge of new ratifications followed years of slow progress.

The treaty’s entry into force will trigger the first Conference of the Parties (COP), where member states will finalize the operational details, including the designation of new marine protected areas, the establishment of benefit-sharing mechanisms, and the creation of scientific and technical advisory bodies. The treaty also introduces new institutional structures, such as a secretariat, a clearing-house mechanism for information sharing, and committees dedicated to compliance, finance, and capacity building.

Global Significance and Challenges Ahead

The High Seas Treaty is widely hailed by environmental groups and ocean advocates as a landmark achievement for global conservation. Greenpeace described it as "the biggest conservation victory ever," emphasizing its potential to safeguard marine ecosystems and support climate resilience by protecting carbon-rich ocean habitats. The treaty also recognizes the importance of traditional knowledge and the "polluter-pays" principle, aiming to ensure that all nations, including developing states, benefit from the sustainable use of ocean resources.

However, the treaty’s effectiveness will depend on robust implementation and continued international cooperation. The first COP, scheduled for 2026, will be critical in setting the rules and governance structures needed to translate the treaty’s ambitions into concrete action. As the world’s oceans face mounting pressures from climate change, overexploitation, and pollution, the High Seas Treaty represents a crucial step toward a more equitable and sustainable future for the planet’s largest shared resource.