The High Seas Treaty enters into force: a new framework for biodiversity in international waters and the road to the first Conference of the Parties

On 17 January 2026 the United Nations Agreement on the conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction, known by the English acronym BBNJ and also as the High Seas Treaty, entered into force. It is the first legally binding framework dedicated to biodiversity in international waters, which cover almost half of the planet and had so far lacked a specific framework. The first Conference of the Parties is scheduled for January 2027.

What the Agreement regulates

The high seas comprise the marine areas that lie beyond the jurisdiction of individual States and account for roughly two thirds of the ocean. The BBNJ Agreement is an implementing agreement under the United Nations Convention on the Law of the Sea (UNCLOS) and addresses four main areas. The first concerns marine genetic resources, with the fair and equitable sharing of the benefits arising from them. The second concerns area-based management tools, including marine protected areas (MPAs). The third concerns environmental impact assessments for planned activities. The fourth concerns capacity building and the transfer of marine technology. Several cross-cutting issues common to the four areas are added to these. The general aim is to provide common rules for a space that hosts some of the least known and least protected ecosystems on the planet.

From adoption in 2023 to entry into force in 2026

The text was adopted on 19 June 2023, after nearly two decades of negotiations led, in the final phase, by President Rena Lee of Singapore. The Agreement opened for signature on 20 September 2023 and remained open until 20 September 2025. Sixty ratifications were required for entry into force: the threshold was reached on 19 September 2025 and, under article 68, the Agreement became binding one hundred and twenty days later, on 17 January 2026. At the beginning of 2026 the Parties numbered more than eighty and the figure continued to grow; the updated count is published in the United Nations Treaty Collection.

The obligations that apply from day one

Some obligations apply from entry into force, while others depend on the establishment of the bodies foreseen. Among the immediate ones, any planned activity under the control of a Party that could affect the high seas or the seabed must follow the environmental impact assessment procedures set out in the Agreement, and governments must make the related notification public. Parties are also required to promote the objectives of the Agreement when they take part in other bodies, for example those that govern shipping, fisheries and the mining of the seabed. Tools that require new bodies, such as the establishment of marine protected areas, will be able to operate once the institutional architecture is in place.

The European Union’s ratification

The Council of the European Union adopted the decision on the conclusion of the Agreement, on behalf of the Union, on 17 June 2024. The European Union deposited its instrument of ratification on 28 May 2025, together with six Member States: Cyprus, Finland, Hungary, Latvia, Portugal and Slovenia. The Union takes part as a regional economic integration organisation; the voting arrangements for organisations of this kind are among the points still under discussion ahead of the first Conference of the Parties.

Towards the first Conference of the Parties

Preparing the institutional and financial arrangements was entrusted to a Preparatory Commission, which met in three sessions: in April 2025, in August 2025 and finally between March and April 2026, closing on 2 April 2026 at United Nations Headquarters in New York. The work, coordinated by co-chairs Janine Coye-Felson of Belize and Adam McCarthy of Australia, produced a report with recommendations and draft decisions to be forwarded to the Conference. Progress was recorded on the voluntary trust fund, the special fund, a memorandum of understanding with the Global Environment Facility (GEF) and the clearing-house mechanism. Still open are, among others, the Conference’s rules of procedure, the financial rules and the model and seat of the Secretariat, for which China, Chile and Belgium have put forward bids. The first Conference of the Parties will be held in New York from 11 to 22 January 2027.

Outlook

The first Conference of the Parties, scheduled from 11 to 22 January 2027, is called on to adopt the institutional and financial arrangements prepared by the Preparatory Commission and to decide the seat and model of the Secretariat. In operational terms, the stated aim is the creation of the first generation of marine protected areas on the high seas by 2030, an instrument described as necessary for the international target of protecting 30 per cent of the ocean by that date. The effectiveness of the Agreement will depend on the breadth of ratifications and on concrete implementation. Several procedural and financial rules remain to be defined, along with the arrangements for electing the members of the subsidiary bodies, some of which may be deferred to the sessions following the first.

In dialogue with the 2030 Agenda

Goal 14 (Life Below Water). The Agreement provides, for the first time, the legal instrument to establish marine protected areas in waters beyond national jurisdiction.
Goal 13 (Climate Action). The ocean absorbs heat and carbon dioxide and regulates the climate, and its protection is linked to climate objectives.
Goal 16 (Peace, Justice and Strong Institutions). The Agreement extends the rule of law to a common space that until now lacked a dedicated framework.
Goal 17 (Partnerships for the Goals). Capacity building, technology transfer and multilateral cooperation are an integral part of the Agreement.