Published on 9 October 2025 in Client Alerts

High Seas and beyond: High Seas Treaty, creating new international law to govern State marine activities, enters into force

On 17 January 2026, the Agreement under the United Nations Convention on the Law of the Sea on the Conservation and Sustainable Use of Marine Biological Diversity of Areas beyond National Jurisdiction (the “High Seas Treaty”) will come into force, following the 60th ratification having been deposited on 19 September 2025.  

Presently, 75 of the 145 signatories have ratified the High Seas Treaty.  Over 22 States and the European Union made declarations at the time of ratifying it, to modify or exclude the scope of application of certain provisions of the High Seas Treaty.

The High Seas Treaty becomes the first legally binding global sea regime to protect marine biodiversity beyond national waters.  UNEP Executive Director Inger Andersen describes this development as “a victory for our oceans, our planet and environmental multilateralism”.  The High Seas Treaty is expected to facilitate the achievement of international biodiversity targets, such as the protection of  “30 per cent of land and sea areas by 2030 under the Kunming-Montreal Global Biodiversity Framework”.  On 10 September 2025, the United Kingdom introduced the Biodiversity Beyond National Jurisdiction Bill, to achieve this target and implement the High Seas Treaty.

António Guterres, Secretary-General of the United Nations, describes the High Seas Treaty as “a lifeline for the ocean and humanity”.  As the world bands together to overcome the “triple planetary crisis of climate change, biodiversity loss, and pollution”, it remains to be seen how the tide will turn.

Volterra Fietta is recognised as the leading law firm for Law of the Sea issues.  For further information, please contact info@volterrafietta.com.