UNCLOS

The BBNJ Agreement: Update on Developments

Almost exactly two years ago, I published an overview of the BBNJ Agreement (the “High Seas Treaty”), describing its background, relationship with UNCLOS and the significance of its adoption by consensus in June 2023.

(See: IMO welcomes adoption of new oceans treaty)

At the time, one important step remained before the Agreement could begin shaping international maritime law in practice: its entry into force.

Today, that step has been completed.

The BBNJ Agreement has now moved from being a successfully negotiated treaty to becoming an operational part of the international legal framework governing the oceans.

(See: BBNJ Agreement | Agreement on Marine Biological Diversity of Areas beyond National Jurisdiction)

The treaty has now entered into force

As discussed in my previous article, the Agreement required 60 ratifications before it could enter into force.

That milestone has now been reached.

Following the deposit of the 60th instrument of ratification, the Agreement entered into force on 17 January 2026, in accordance with its own provisions.

(See: Press Releases | Agreement on Marine Biological Diversity of Areas beyond National Jurisdiction)

This marks an important transition.

For almost twenty years, the international community debated whether such an agreement could be negotiated.

Today, the discussion has shifted towards how it should be implemented.

The focus now moves from negotiation to implementation

As is often the case in international law, adopting a treaty is only the beginning.

The real challenge lies in transforming broad treaty obligations into practical legal and institutional mechanisms.

To facilitate this process, States have established a Preparatory Commission (PrepCom), which is currently developing recommendations for the institutional framework necessary to implement the Agreement.

Among the issues under consideration are:

• Rules of Procedure for the future Conference of the Parties (COP);
• financial arrangements;
• subsidiary scientific and technical bodies;
• compliance mechanisms;
• institutional arrangements; and
• practical procedures for implementing the Agreement.

In many respects, the work now resembles that undertaken following the adoption of other major international environmental agreements, where the treaty text establishes the legal framework, while the Parties subsequently develop the detailed rules needed for its practical application.

The first Conference of the Parties

The next major milestone will be the first Conference of the Parties (COP1).

Under Article 47 of the Agreement, the first COP must convene within one year of the treaty’s entry into force.

It will become the principal decision-making body under the Agreement and will begin adopting the institutional and procedural decisions necessary to make the new regime operational.

For international lawyers, this stage is particularly interesting.

While the negotiations have concluded, many important legal questions remain to be addressed through decisions adopted by the Parties themselves.

(See: Background | Agreement on Marine Biological Diversity of Areas beyond National Jurisdiction)

Supporting the global “30 by 30” objective

One of the principal political objectives associated with the BBNJ Agreement is the international commitment to protect 30% of the world’s land and oceans by 2030, commonly referred to as the “30×30” target.

The Agreement itself does not require that 30% of the oceans become protected.

(See: UN biodiversity treaty enters into force, aims to protect 30% of oceans by 2030 | Reuters)

Rather, it establishes—for the first time—a comprehensive legal mechanism enabling States Parties collectively to designate Marine Protected Areas (MPAs) in areas beyond national jurisdiction.

The coming years are therefore likely to see increasing discussions concerning:

• identification of candidate Marine Protected Areas;
• scientific criteria for designation;
• governance arrangements;
• monitoring and compliance; and
• balancing conservation objectives with legitimate maritime activities.

How successfully these issues are resolved will largely determine the Agreement’s long-term effectiveness.

(See: IMO welcomes entry into force of the BBNJ Agreement)

A new chapter in the law of the sea

The BBNJ Agreement represents the third implementing agreement adopted under UNCLOS, following the 1994 Part XI Agreement and the 1995 Fish Stocks Agreement.

Its significance therefore extends beyond marine biodiversity.

It also demonstrates that UNCLOS continues to evolve as the constitutional framework for the world’s oceans through the adoption of implementing agreements addressing new challenges not foreseen when the Convention was negotiated more than forty years ago.

(See: A historic milestone for ocean governance: the BBNJ treaty enters into force | Intergovernmental Oceanographic Commission)

Concluding remarks

When I wrote about the BBNJ Agreement in July 2024, the focus was understandably on the successful conclusion of nearly two decades of negotiations.

Two years later, the discussion has changed fundamentally.

The treaty has entered into force.

Attention has shifted from negotiating legal text to building institutions, developing implementation mechanisms and preparing for the first Conference of the Parties.

As with many developments in international law, the adoption of a treaty is often remembered as the historic moment.

In reality, however, it is usually only the beginning.

The coming years—and particularly the work of the first Conference of the Parties—will determine how the BBNJ Agreement develops in practice and how effectively it contributes to the international community’s ambition of protecting 30% of the world’s oceans by 2030.

For anyone with an interest in UNCLOS and international maritime law, this is a process well worth following.