High Seas Treaty (BBNJ) – A Law for the Ocean’s “White Spaces”

On 17 January 2026, the High Seas Treaty – formally entitled the Agreement under the United Nations Convention on the Law of the Sea (UNCLOS) on the Conservation and Sustainable Use of Marine Biological Diversity of Areas beyond National Jurisdiction (BBNJ) – officially entered into force, marking an important turning point in modern international law, as for the first time the international community has a relatively comprehensive legal framework to govern the parts of the ocean that lie “beyond the boundaries” of all States.

From governance gaps to new “rules of the game” on the high seas

The high seas and “the Area” of the seabed beyond national jurisdiction occupy most of the ocean space, serving as major arteries of global trade and also as a “data repository” of marine biodiversity, marine genetic resources, and potential pharmaceutical substances. However, for many decades, governance in these areas has been largely fragmented along sectoral lines (fisheries, shipping, research, etc.), lacking a sufficiently strong overarching mechanism to establish common standards for conservation, impact assessment, and benefit-sharing. This very gap has allowed pressures from overfishing, pollution, biodiversity loss, and climate change to accumulate faster than regulatory capacity.

BBNJ emerged as a “missing link” in the chain of the law of the sea: the Agreement was adopted on 19 June 2023, opened for signature on 20 September 2023, and reached the threshold of 60 instruments of ratification on 19 September 2025, thereby triggering the provision on entry into force after 120 days.

Notably, BBNJ does not merely remain at the level of a “declaration of principles”, but establishes a distinct institutional architecture, comprising the Conference of the Parties (COP), a scientific and technical body, a Clearing-House Mechanism for the disclosure of data and information, as well as specialized committees on capacity-building and benefit-sharing.

From a “process-based governance” perspective, BBNJ changes the way the world makes decisions on the conservation of the high seas: moving from reliance on voluntary goodwill to a mechanism grounded in procedures, standards, and transparency obligations - particularly significant in the current context, where the proportion of protected high seas areas remains very low.

Entry into force is not the end point

First, the challenge of coordinating competences. The high seas are already governed by multiple sector-based institutions. While BBNJ seeks to provide an additional governance “backbone”, its effectiveness depends on coordination with regional fisheries management organizations, maritime transport regimes, and other relevant bodies, in order to avoid overlap or responsibility evasion. This is a challenge highlighted by European media and international observers: conservation cannot succeed if fisheries regulations and the enforcement of marine protected areas (MPAs) are not “connected” with existing mechanisms.

Second, monitoring and enforcement capacity. No matter how well designed, a treaty may remain merely “good on paper” in the absence of effective implementation tools. The Associated Press (AP) has noted that options such as satellite tracking, data-sharing, and international control mechanisms will need to be further specified at the initial sessions of the Conference of the Parties (COP).

Third, finance and equity. BBNJ sets out objectives for benefit-sharing and capacity support for developing countries, but these objectives require financial mechanisms that are workable in practice - from the costs of the institutional machinery to scientific resources needed for proposing and monitoring MPAs. Even EU documents acknowledge that the scale of the initial budget and the operational costs of many components will have to be decided by the COP, while emphasizing the need for technical and technological support to avoid “capacity inequality” among groups of States.

BBNJ does not regulate deep-seabed mineral exploitation; this matter remains within the mandate of the International Seabed Authority (ISA). As a result, the goal of high seas conservation cannot be fully realized if developments in deep-seabed mining proceed faster than the capacity to assess ecosystem risks.

Implementation challenges

With the Agreement now in force and the number of Parties having exceeded 80, including major maritime States, the question is no longer whether to sign, but how far and how fast implementation will proceed.

If BBNJ generates the “soft power” of law - namely norms and procedures - then upcoming COPs must translate that soft power into hard outcomes, such as an effectively operative list of MPAs; sufficiently robust environmental impact assessment (EIA) standards; a transparent benefit-sharing mechanism; and an open marine data infrastructure that enables scientific input and societal oversight. Preparatory matters for COP1 have already been placed on the agendas of pre-sessional mechanisms (prepcom), ranging from rules of procedure and criteria for selecting the scientific and technical body, to modalities for operating the Clearing-House Mechanism and financial rules.

At a time when humanity increasingly speaks of green transitions and the “30x30” target, BBNJ represents a clear test of multilateralism: whether the world can govern a vast global commons through rules, or whether the high seas will continue to be “fragmented” by sectoral interests and implementation gaps. The Agreement has opened the door; what remains depends on the extent to which States translate commitments into action and transform law into real capacity to protect the ocean in practice.

BBNJ comprises four pillars and a new institutional architecture

1. Area-based management tools and conservation measures (in particular marine protected areas – MPAs) on the high seas;

2. Environmental impact assessment (EIA) for activities with the potential to cause harm;

3. Marine genetic resources (MGRs) and the fair and equitable sharing of benefits;

4. Capacity-building and the transfer of marine technology for developing countries.