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 maximising 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.
