Photo by Silas Baisch
The UK has moved a significant step closer to ratifying the landmark High Seas Treaty after the Biodiversity Beyond National Jurisdiction (BBNJ) Bill received royal assent on 12 February, becoming an Act of Parliament. However, the government confirmed that additional secondary legislation is still required before full ratification can be achieved.
The BBNJ Agreement, commonly known as the High Seas Treaty, is a landmark international agreement that will, for the first time, create a legal mechanism to establish protected zones in international waters. Two-thirds of the ocean lies beyond any nation’s jurisdiction, containing extraordinary biodiversity and ecosystems vital to planetary health, yet these waters have been left open to exploitation and degradation without the protection of national laws.
The treaty, which entered into force on 17 January 2026 after reaching 60 ratifications in September 2025, will enable creation of marine protected areas on the high seas, require environmental impact assessments for activities that could significantly impact marine ecosystems, and ensure fair sharing of benefits from research into marine genetic resources with potential applications in medicines, cosmetics and biotechnology.
The UK government noted that whilst passing of the Act is an essential step, it is not the final one. To ratify the BBNJ Agreement, the UK needs to put in place secondary legislation that will ensure the country can meet some of its obligations under the treaty, including amending the current marine licensing regime to ensure compliance with environmental impact assessment obligations.
Hugo Tagholm, director of Oceana UK, said it was great news that the UK has passed its bill to begin ratifying the High Seas Treaty, which can and must represent a huge win for the global ocean. He added that the international community is finally waking up to the fact that far from a distant, lawless wasteland where overfishing is rampant and rubbish is dumped, the high seas matter as the beating heart of a healthy ocean that gives us a stable climate, food to eat and air to breathe.
Until the High Seas Treaty came into effect, only 1% of international waters, which currently cover two-thirds of the ocean, had been protected. The BBNJ Agreement creates, for the first time, the tools to establish marine protected areas on the high seas and sets obligations on how ocean resources should be used sustainably.
Many shark populations have been pushed to the brink of extinction, and sea turtles face mounting threats from pollution, habitat loss and climate change. The UK government emphasised that vulnerable species are facing increasing threats and pressures in these unprotected waters.
The government confirmed it is committed to getting the secondary legislation process right and building a robust legal foundation to ensure the UK can play a meaningful role in protecting the high seas for generations to come. The process takes time, but officials stated they are working towards full ratification.
The first meeting of the Conference of the Parties must take place before 16 January 2027, and the UK intends to play a leading role at this and subsequent meetings. However, despite receiving royal assent, the UK is not yet legally bound to measures the treaty introduces and risks exclusion from the first-ever “Ocean COP” conference if ratification is not completed in time.
The agreement has so far been ratified by 85 parties, including the EU and 16 of its member states, and signed by 145 countries. The EU and its member states led the political process and negotiations of this agreement, whose conclusion and adoption in 2023 was described as a major success of multilateralism and a historic achievement in international law and ocean governance.
The High Seas Treaty was announced in November 2025 as winner of the prestigious Earthshot Prize in the “Revive our Oceans” category, recognising decades-long efforts to put in place a groundbreaking legal framework to protect marine biodiversity in international waters.