UK ratifies landmark treaty to protect the high seas

The UK has formally ratified the High Seas Treaty, joining international efforts to protect marine life in waters beyond any single country’s control.

The agreement, officially known as the Biodiversity Beyond National Jurisdiction Agreement, covers areas that make up nearly two-thirds of the world’s ocean. For the first time, it creates a legal route for countries to establish marine protected areas on the high seas. It also sets rules for environmental assessments and the fair sharing of benefits from marine genetic resources.

The treaty entered into force in January 2026 after receiving the 60 ratifications needed under international law. Since then, support has continued to grow, with 145 countries signing the agreement and 89 formally ratifying it. The UK has now completed its own ratification by depositing its formal documentation with the United Nations. The first Conference of the Parties is expected in January 2027.

This matters because healthy oceans support food supplies, biodiversity, oxygen production and climate resilience. Marine ecosystems do not follow national borders, so effective protection depends on countries working together. The UK's ratification adds further momentum to a global agreement that could protect vulnerable habitats for future generations.