The high seas have always come with high stakes – and for all the living things in the water, these couldn't be higher.

The vast two-thirds of the ocean beyond national jurisdiction has been hit by overfishing, shipping traffic and plastic pollution, while emerging threats like deep-sea mining and marine carbon dioxide removal proposals loom on the horizon. Although already subject to international law, there was no global framework to protect these waters. With the UN High Seas Treaty (formally known as the Biodiversity Beyond National Jurisdiction, or BBNJ, Agreement) entering into force on January 17, 2026, a new legal framework for conserving and sustainably using marine biodiversity in these shared waters is in place.

At the UN biodiversity summit (COP17) in Yerevan, Armenia, this week, experts met to figure out how different global rules can work together to save the ocean.

The Convention on Biological Diversity (CBD) is the broad framework for biodiversity conservation. Its Kunming-Montreal Global Biodiversity Framework sets a target to ensure that, by 2030, at least 30% of the world's terrestrial and inland water areas, as well as coastal and marine areas, are effectively conserved and managed.

The BBNJ Agreement complements it by establishing rules for conserving and sustainably using marine biodiversity in areas beyond national jurisdiction. It covers everything from marine genetic resources and how to share their benefits in a fair and equitable manner to area-based management tools, including marine protected areas, environmental impact assessments, capacity-building and marine technology transfer. These measures are designed to strengthen international cooperation and support developing countries in implementing the agreement.

China played a key role in the negotiations and ratified the treaty on December 15, 2025, becoming one of its first Parties. Now, Beijing has thrown its weight behind Xiamen, in Fujian province, to host the treaty's secretariat. Brussels and Valparaiso are also in the running, with the final decision set for January 2027. To help developing countries participate in the process, China has pledged $3 million to a voluntary trust fund.

Meanwhile, seven West African countries, led by Nigeria, are working to advance a proposal for a highly and fully protected marine protected area in the Guinea–Canary Currents Convergence Zone. At COP17 on October 26, Nigeria outlined the initiative, which is being developed through the West Africa BBNJ Coordination Committee. The intitiative demonstrates the need for scientific cooperation, data-sharing, monitoring and enforcement, sustainable financing and support for coastal livelihoods.

Turning such proposals into effective protection will require reliable scientific data. Deep-sea surveys, biodiversity monitoring, satellite observations and vessel-tracking data can help identify ecologically important habitats, establish baselines and inform marine protected area planning on the high seas. Environmental impact assessments can also help evaluate the potential risks of human activity to vulnerable ecosystems.

Although the CBD and the BBNJ Agreement operate under separate frameworks, closer coordination is essential. Delivering the 2030 targets will require international rules to be backed by reliable science, technical capacity and sustained cooperation.