The High Seas Treaty, formally known as the Agreement on the Conservation and Sustainable Use of Marine Biological Diversity of Areas Beyond National Jurisdiction (BBNJ agreement), is an international legally binding instrument designed to protect marine life in the oceans that lie beyond national borders. After nearly 20 years of negotiations, it officially entered into force on January 17, 2026, following ratification by 60 countries.
The High Seas Treaty: what it is
The agreement covers the area beyond national jurisdiction (ABNJ) which constitutes approximately two-thirds of the world’s oceans (including the High Seas and the seabed called ‘the Area’). To date, nearly 80 countries have ratified the agreement and are therefore legally bound by it.
The agreement is made up of four key pillars:
- Pillar 1 establishes rules for sharing benefits from scientific research on marine genetic resources (MGRs).
- Pillar 2 enables the creation of area-based management tools (ABMTs), such as marine protected areas (MPAs) to protect biodiversity.
- Pillar 3 requires environmental impact assessments (EIAs) of potential damage from human activities in the high seas.
- Pillar 4 supports developing nations through capacity building and technology transfer, in marine science and conservation.
The agreement is significant for conservation in that it provides a framework for the creation of area-based management tools that can contribute to the 30% by 2030 goal from the Global Biodiversity Framework – Target 3 (GBF). At macro-regional scale, the 30% targets are also written in the European Union Biodiversity Strategy and the goals for the UNEP Mediterranean Action Plan. Globally, currently less than 2% of the ABNJ is protected.
The Mediterranean faces unique challenges
The Mediterranean is often considered to be a microcosm of the global oceans. It is one of the critically affected regions in the world in terms of the triple planetary crisis – climate change, biodiversity loss and pollution – often experiencing these stressors faster than the rest of the world. As such, its conservation should be prioritised at a global scale.
However, the Mediterranean also presents unique challenges due to its scale. None of the opposite coasts are further than 400 nautical miles apart, so if all states were to declare exclusive economic zones (EEZs) there would be no ABNJ in the Mediterranean.
Despite this, the BBNJ agreement continues to have relevance. The agreement recognises that coastal states have special rights and provides opportunities to increase coherence between the Mediterranean Action Plan and other regional bodies. It ensures that conservation efforts for migratory species are not undermined by political boundaries.
The treaty will help fulfil the region’s commitment to the 30×30 target by providing a framework for cooperation in areas that remain beyond national jurisdiction and promote cooperation between national jurisdictions and the ABNJ. Realistically, this should also extend to multilateral cooperation between coastal states of the Mediterranean due the legal precedents that are written into the agreement. In reality global agreements are never implemented at a global scale, but at a regional level. The agreement has the potential to empower the Mediterranean regional seas programme. Role of the regional seas and regional, national and local stakeholders will be crucial in the implementation of agreement in the field.
The High Seas Treaty: what comes next
Yet there is still work to be done. A final meeting of the BBNJ Preparatory Commission is scheduled for next month (March 23 – April 2) to finalize recommendations on governing structures and financial rules. Before the end of 2027, the first conference of parties (COP1) should be convened and this will establish the permanent bodies, the Secretariat, and the scientific committee to review the first proposals for High Seas MPAs. Finally, efforts will continue to encourage major economies that have signed but not yet ratified, such as the United States, to formally join.
