Less than three weeks into 2026, the international ocean community celebrated a key achievement: the Agreement on the Conservation and Sustainable Use of Marine Biological Diversity of Areas Beyond National Jurisdiction (often called the BBNJ Agreement or the High Seas Treaty) officially came into force.
This is the first legally binding, global framework to govern biodiversity in areas beyond national jurisdictions — an area covering approximately 65% of the ocean and 43% of the Earth’s surface. Because of its size and remoteness, management of this area, known as the “high seas,” has been historically disjointed. The new treaty aims to provide the much-needed thread to stitch together a patchwork of current governance systems.
Work now begins to build a framework that supports international climate and biodiversity goals. This includes the creation of new decision-making bodies, procedures for environmental impact assessments (EIAs) in the high seas, rules for accessing and benefit-sharing of marine genetic resources, and critically, a mechanism for the establishment of Marine Protected Areas (MPAs) and other effective area-based conservation measures (OECMs) on the high seas.
We’re at a pivotal moment as the effectiveness of establishing MPAs during the High Seas Treaty negotiations will greatly impact the success of sustainable ocean management efforts globally. Lessons learned from already-established high seas MPAs in the North Atlantic and Southern oceans can help shape the most successful approaches.
Why Are High Seas MPAs Important?
The high seas are crucial in absorbing about 90% of excess heat and a quarter of carbon dioxide emissions through physical, chemical and biological processes. This area also supports important fisheries, including tuna, krill and squid. Beyond these high value species, biodiversity here remains poorly described with estimates that hundreds of thousands of species remain to be discovered. Related to this vast biodiversity, the ecosystem services provided by the high seas (including chemical compounds for pharmaceuticals, nutrient cycling and climate regulation) are thought to be extremely valuable.
Despite their importance, the high seas are facing a number of significant threats from unsustainable fishing and shipping practices, climate change, land-based pollution and mining. Well-designed high seas MPAs and OECMs, which manage a wide range of human activities within designated zones, are essential parts of the solution. They have been shown to promote ecosystem recovery and resilience, including through increased abundance and biomass and greater biodiversity. Their benefits typically extend beyond their boundaries too, boosting biomass and biodiversity through what’s known as the spillover effect.
High seas MPAs will also be crucial to achieving the global ambition to protect at least 30% of the ocean by 2030 — a target formalized within the Global Biodiversity Framework (Target 3, also known as 30 by 30). Their documented power to protect healthy ecosystems and encourage the recovery of impacted ecosystems would significantly contribute to achievingcould contribute to achieving this target –– though there would still be a need for large no-take MPAs in national waters where many threats are concentrated. However, with only 1.6% of the high seas protected as of February 2026, a huge increase in the rate of MPA designation will be needed.
Effectively addressing the full suite of high seas threats will require more than the establishment of MPAs. Sector-specific and global measures are also needed, such as International Maritime Organization (IMO) shipping routing/speed and biofouling controls, regional fisheries management organisation (RFMO) rules for fisheries, EIAs under the High Seas Treaty and economy-wide action on greenhouse gases and land-based pollution.
Sustainable Ocean Plans (SOPs), that are currently deployed only in national waters, may be an effective means to coordinate these different bodies. These plans act as overarching frameworks to support the sustainable management of 100% of areas under national jurisdiction. Exploring their development in a high seas context may help extend focus beyond a simple target of 30% protection towards more holistic and multifaceted 100% sustainable management.
How Are the Current High Seas MPAs Managed?
High seas MPAs are currently established in the Southern and North Atlantic oceans. In the Southern Ocean, the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) was established in 1982 following concerns over the overfishing of krill, and forms part of the Antarctic Treaty. In the North Atlantic Ocean, the Convention for the Protection of the Marine Environment of the North-East Atlantic (OSPAR) was convened to combat marine pollution after a series of extensive oil spills. Since their formation, both intergovernmental bodies have delineated MPAs on the high seas, providing limited, but useful, case studies to learn from.
CCAMLR
Commission for the Conservation of Antarctic Marine Living Resources
Members: 26 countries plus the European Union, and 10 Acceding States (parties without a vote)
Number of high seas MPAs: 2 (South Orkney Islands MPA, Ross Region MPA)
Decision-making process: unanimous vote
Management responsibility: members
Funding: primarily national funding with assistance from the MPA Special Fund
Since 2002, CCAMLR has been working to determine a representative system of MPAs in the Southern Ocean. A formal agreement was made for this network to be completed by 2012 (Conservation Measure 91-04), but was delayed because its members could not find consensus on the details of this system. As such, only two MPAs are in operation, covering just 5% of the Southern Ocean.
While management responsibility lies with CCAMLR, both MPAs are primarily monitored by a small group of members. The South Orkney Islands MPA is monitored primarily by the United Kingdom through its Blue Belt Overseas Territory work. The Ross Sea MPA has largely been monitored by New Zealand, the U.S., Italy and South Korea, with New Zealand also conducting enforcement activities using its own maritime surveillance and patrols.
The costs of managing these MPAs are mostly covered by national funds from the engaged nations, rather than a central CCAMLR pot. For example, the five-year Ross Sea Region Research and Monitoring Programme (Ross-RAMP) was funded exclusively by the New Zealand Ministry of Business, Innovation and Employment (MBIE). There is, however, an MPA Special Fund, that was set up in 2005, to support the development and implementation of MPAs as a complement to these other funding mechanisms.
OSPAR
Convention for the Protection of the Marine Environment of the North-East Atlantic
Members: 16 contracting parties
Number of high seas MPAs: 11 (2 fully in areas beyond national jurisdiction – Charlie Gibbs South MPA, and Milne Seamount Complex MPA).
Decision-making process: unanimous vote or three-quarters majority
Management responsibility: members, except when coordinating with existing sector-specific intergovernmental bodies
Funding: primarily national funds with no central pot
Recommendation 2003/3 adopted by OSPAR proposed the establishment of a well-managed and ecologically coherent network of MPAs. In the North-East Atlantic Environment Strategy (NEAES) 2030, OSPAR outlined their goal of ensuring this network covers at least 30% of its maritime area in line with 30 by 30. As of their last Assessment Report (2023), 10.9% of the OSPAR region is covered by MPAs — with 11 located in the high seas.
The leniency in decision-making of OSPAR, where if a unanimous vote cannot be reached, a decision may be adopted by a three-quarters majority, contrasts with the voting system in place in the CCAMLR area.
As the management of the high seas MPAs is the responsibility of OSPAR members collectively, it relies heavily on information sharing and coordinated scientific work. Research expeditions from the U.K., U.S. and Russia have provided vital monitoring data for the Charlie-Gibbs MPAs, but monitoring activities for the Milne Seamount Complex remain limited.
Enforcement responsibility depends on the activity in question. Both fisheries management and maritime transport are not in the OSPAR Convention mandate. Instead, OSPAR has a cooperation agreement with other international authorities responsible for these sectors. For fishing, regulation relies on the North-East Atlantic Fisheries Commission (NEAFC), whereas shipping standards are enforced by the International Maritime Organization. Similarly, mineral extraction is managed by the International Seabed Authority (ISA).
What Learnings Can Be Taken for the High Seas Treaty?
Both CCAMLR and OSPAR MPAs demonstrate that large high seas MPAs can be established and persist in an intergovernmental setting. They are backed by legally established, multilateral frameworks that are not dependent on a singular government for financial stability or management, making them resilient to changes in geopolitical climate. They can be integrated with other regulatory frameworks and bodies that are active across the high seas, including the IMO, ISA and RFMOs. Further, they can attract funding for scientific research and monitoring activities from national science agencies across the globe.
However, both CCAMLR and OSPAR MPAs demonstrate limitations. With no long-term funding model, and no central budgets or staff, capacity for MPA management and enforcement is dependent on sporadic volunteer contributions from nations or scientific agencies. The pursuit of consensus in decision-making in CCAMLR has also generated significant delays in the delivery of effective marine protection.
There are, therefore, three key lessons that the High Seas Treaty can learn from these existing mechanisms:
- Avoid institutional paralysis linked with consensus decision-making. Fortunately, the High Seas Treaty is already taking steps to alleviate this. A similar decision-making model to OSPAR has been proposed, where if consensus cannot be reached amongst member nations, a three-quarter majority vote can pass the adoption of an MPA. This voting system must be kept intact to ensure future proposals of high seas MPAs do not become stifled and hindered by incompatible national political agendas.
- Create a specific MPA funding mechanism that is not solely reliant on voluntary national contributions. A robust general funding model is in development for the High Seas Treaty, which includes assessed contributions from parties and a voluntary trust fund for developing state participation in the treaty. A special fund has further been proposed to funnel monetary benefits derived from marine genetic resources, as well as the Global Environmental Facility trust fund for capacity building and implementation. However, none of these funds are specifically reserved for the establishment and management of MPAs. A dedicated and equitable funding mechanism for MPAs will be a key element to discuss ahead of the first BBNJ Conference of Parties (COP) later this year.
- Ensure dedicated infrastructure and capacity for monitoring and enforcement processes. While there is already intention to create a specific body to consider MPA management plans, dedicated infrastructure and capacity, including for technical expertise and monitoring and enforcement, needs to be another focus ahead of the first BBNJ COP. Learning from OSPAR’s approach, and taking a Sustainable Ocean Plan approach, this dedicated body should work collaboratively with existing intergovernmental management bodies, such as RFMOs for fisheries, the ISA for mineral extraction and IMO for shipping. This will help alleviate the strain of managing multiple sectors and stop the duplication of efforts.
More broadly, however, the success of high seas protection under the BBNJ Agreement will depend not only on institutional design, but also on navigating complex geopolitical realities. Negotiations over marine protection in areas beyond national jurisdiction have consistently reflected broader North–South dynamics, concerns over equity and differing national priorities. Many developing nations face significant capacity constraints in participating effectively in designation, monitoring and enforcement processes. At the same time, some remain cautious about expansive “no-take” zones, viewing them through the lens of future access to resources, fisheries interests or strategic maritime considerations.
If the High Seas Treaty is to succeed, it must therefore address not only governance architecture and funding models, but also equity, capacity and political trust among parties. If the BBNJ COP fails to secure durable financing and an enforceable management model, designation alone will not deliver protection.
Nevertheless, with an ever-growing list of ratified parties there is clearly strong intergovernmental support to deliver effective protection through the High Seas Treaty, and the protected areas in CCAMLR and OSPAR regions, which despite their challenges, demonstrate what can be achieved. By working collectively toward a robust mechanism for the designation of MPAs through the High Seas Treaty, we can ensure that Earth’s largest public common is protected and restored, for the benefit of all and for generations to come.