High Seas Treaty redrawing global ocean rules

For centuries, the high seas have embodied a defining principle: freedom. States have enjoyed broad rights to navigate, fish and conduct scientific research in areas beyond national jurisdiction, while the mineral resources of the international seabed are governed by the principle that they constitute the common heritage of humanity. As long as these two principles remained broadly compatible, the existing legal order proved remarkably durable.

That balance, however, has become increasingly difficult to sustain.

In January, 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 — also called the BBNJ Agreement or the High Seas Treaty — came into force. Concluded after nearly two decades of negotiations, it is widely regarded as the most important development in international law of the sea since the adoption of the United Nations Convention on the Law of the Sea. More importantly, it reflects a broader shift in global ocean governance — from maximizing access to safeguarding sustainability.

The agreement comes at a time when the shortcomings of the existing governance framework have become increasingly apparent. Areas beyond national jurisdiction, including the high seas and the international seabed area, account for almost two-thirds of the world's oceans. Yet governance of these waters has long been fragmented. While different international bodies oversee shipping, fisheries, seabed mining and other activities, no single legal framework has comprehensively addressed the conservation of marine biodiversity across these spaces.

The result has been growing pressure on marine ecosystems. Advances in science and technology have made previously inaccessible marine genetic resources and deep-sea minerals increasingly valuable, intensifying competition over emerging ocean resources. At the same time, biodiversity loss, climate change and marine pollution have exposed the limitations of governance arrangements that were largely designed around resource utilization rather than ecosystem protection.

The BBNJ Agreement seeks to fill that gap. Through rules on marine genetic resources, area-based management tools such as marine protected areas, environmental impact assessments, and capacity building and technology transfer, it establishes the first comprehensive implementation framework dedicated specifically to conserving biodiversity in areas beyond national jurisdiction.

Its significance, however, extends well beyond environmental governance. Like many international agreements, the BBNJ Agreement is not simply about what it regulates, but also about who helps shape the rules. Decisions concerning marine protected areas, access to marine genetic resources and environmental assessments inevitably influence future patterns of resource use. Countries with stronger scientific capabilities, more advanced marine technologies and greater monitoring capacity may be better positioned to participate in these processes and to shape the practical implementation of the treaty.

Such participation is entirely legitimate under the agreement. Yet it also illustrates why implementation will inevitably involve strategic considerations alongside environmental ones. As governance gradually shifts from broad freedom toward more structured regulation, the allocation of influence over the global commons becomes an increasingly important issue in its own right.

This explains why the treaty's implementation is likely to prove more challenging than its negotiation. Geopolitics remains an unavoidable reality. The United States has signed but not ratified the agreement, while Russia has yet to sign it, limiting the treaty's universality. At the institutional level, the relationship between the BBNJ Agreement and existing bodies — including the International Maritime Organization, the International Seabed Authority and regional fisheries management organizations — will require careful coordination to ensure that the treaty complements rather than undermines established mandates.

Differences in national capacity present another challenge. Effective implementation depends not only on legal obligations but also on scientific expertise, financial resources and technological capabilities. Ensuring that developing countries can participate meaningfully through capacity building and technology transfer will therefore be essential if the agreement is to deliver genuinely inclusive governance.

Nor should conservation tools themselves become sources of new contention. Area-based management measures are intended to protect marine ecosystems, not to create new forms of competition over ocean space. Preserving an appropriate balance between conservation and sustainable use will remain one of the agreement's most important tests.

Against this backdrop, China has consistently supported the treaty while emphasizing both effective conservation and equitable participation. As a full participant throughout the negotiations and among the first parties to ratify the agreement, China has sought to safeguard the legitimate interests of developing countries while actively contributing to the evolution of global ocean governance. Its declarations upon ratification — including those concerning non-retroactivity, the treaty's scope of application, respect for existing international legal frameworks and decision-making by consensus — reflect both support for the agreement and a commitment to legal certainty.

China has also promoted international cooperation on marine genetic resources, capacity building and technology transfer. Its bid to host the treaty's secretariat in Xiamen, Fujian province, further demonstrates its willingness to contribute public goods to global ocean governance and to support the treaty's long-term implementation.

The High Seas Treaty represents an important evolution in the governance of the global commons. But its success will ultimately depend not on the text alone, but on how countries implement it in practice. The real challenge lies in reconciling conservation with sustainable use, strengthening international cooperation without undermining legitimate rights, and ensuring that the oceans remain a shared space governed by rules that are both effective and equitable. As the treaty moves from negotiation to implementation, that balance — not the agreement itself — will determine whether this new chapter in ocean governance lives up to its promise.

Jiang Xiaoyi is a professor at the China Institute of Boundary and Ocean Studies, Wuhan University; and Zhang Qiyu is a research assistant at the same institute.

The views don't necessarily reflect those of China Daily.