The UK has formally ratified the landmark High Seas Treaty, taking its place in a new global effort to protect marine wildlife in the vast expanses of ocean beyond national borders.
Officially known as the Biodiversity Beyond National Jurisdiction Agreement, the Treaty provides the first overarching legal framework for conserving and sustainably using biodiversity on the high seas. These international waters cover nearly two-thirds of the world’s ocean, yet until now there has been no effective global mechanism for establishing marine protected areas within them.
The UK signed the Treaty in 2023, but ratification was only completed on 10 July 2026, when the formal documentation was deposited with the United Nations. This followed the passing of the Biodiversity Beyond National Jurisdiction Act earlier this year.
The Treaty itself entered into force in January, after securing the required 60 ratifications. By ratifying now, the UK will be able to participate fully in its implementation and take its place at the first Conference of the Parties in January 2027. The Government says this will help deliver the international commitment to protect 30% of the ocean by 2030.
For whales, dolphins and porpoises, this could be hugely significant. Cetaceans are oblivious to boundaries drawn on maps. Many travel enormous distances between feeding, breeding and nursery grounds, moving through national waters and across the high seas.
The Treaty creates an opportunity to protect not simply isolated areas, but the migratory routes connecting them. WWF has highlighted its potential to establish “blue corridors” for whales, dolphins, sharks, tuna and sea turtles, while also addressing the combined pressures of climate change, pollution, overfishing and possible seabed mining.
It also introduces requirements for assessing the environmental impact of activities that could harm high seas biodiversity. But ratification does not, by itself, create a single protected area or remove a single threat. As Blue Marine Foundation has warned, attention must now turn to establishing ambitious, highly protected areas rather than protections that exist principally on paper.
That is where evidence becomes indispensable and where ORCA’s work has a vital contribution to make.
Through our network of trained volunteer Marine Mammal Surveyors, Ocean Conservationists and industry partners, ORCA collects data across extensive areas of the Northeast Atlantic and beyond. Our surveys help reveal where cetaceans are found, how their distribution and abundance change, and which routes and habitats may be particularly important.
Long-term monitoring will be essential both to identify areas deserving protection and to measure whether that protection is working. It can also reveal changes linked to warming seas, shifting prey distributions, shipping and other human pressures.
Scientists at Plymouth Marine Laboratory have described the Treaty as an extraordinary opportunity, while cautioning that “making the rules is actually only the beginning”. Delivering them will require the best available science, effective monitoring and international cooperation.
The UK’s ratification should therefore be celebrated - but it must also be treated as a starting point. ORCA will continue gathering the evidence needed to ensure that the lives moving beneath the surface of the high seas are seen, understood and properly protected.
There is also a considerable distance to travel before this becomes a genuinely global system of protection. Although 145 countries signed the Treaty, only 92 have so far become full Parties. The United States, Australia, Canada and India are among those yet to ratify, while Russia has not joined at all. Universal participation matters: migratory species cannot be protected effectively if influential maritime, fishing and industrial nations remain outside the agreement. The UK must therefore use its diplomatic influence not only to secure strong implementation, but to encourage every remaining government to ratify or accede.
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