On 10 January 2023, Estonia deposited the instrument of accession to the treaty, joining Canada, Denmark, Estonia, Norway, South Africa and Turkey, to make six Contracting States. Four of these States each have more than 2 million units of gross tonnage. To come into force, the 2010 HNS Protocol needs six more States to ratify or accede to it plus the required contributing cargo.

The text of the Agreement, which takes the form of a new Implementing Agreement under the United Nations Convention on the Law of the Sea (UNCLOS) to protect and sustainably use the resources of these areas, was agreed on 4 March 2023. The Agreement establishes marine protected areas in the high seas which will help achieve the global goal of protecting 30 per cent of the world’s oceans—set out in the UN’s Global Biodiversity Framework agreed in December 2022 in Montreal at the Convention on Biological Diversity when countries pledged to protect 30 per cent of ocean, land and coastal areas by 2030. These areas will put limits on how much fishing can take place, the routes of shipping lanes and exploration activities such as deep sea mining—when minerals are taken from a seabed 200 metres or more below the surface. The treaty will also require assessing the impact of economic activities on high seas biodiversity. Developing countries will be supported in their participation in and implementation of the new treaty by a strong capacity-building and marine technology transfer component, funded from a variety of public and private sources and by an equitable mechanism for sharing the potential benefits of marine genetic resources.

States parties are to apply the Agreement’s new environmental safeguards to activities “within their jurisdiction or control” and will need to ensure that high seas activities falling within their jurisdiction or control comply with the new requirements of (inter alia) environmental impact assessments, area-based management tools and marine