As of October 2024, the United Nations Convention on the Law of the Sea (UNCLOS) counts 169 sovereign states and the European Union among its parties, marking a notable expansion of the treaty’s reach. This international agreement provides the legal foundation governing all marine and maritime activities, and its broad adoption represents progress in global ocean stewardship.
The convention originated from the third United Nations Conference on the Law of the Sea, held between 1973 and 1982. It superseded the four treaties that comprised the 1958 Convention on the High Seas. UNCLOS entered into force in 1994, one year after Guyana became the 60th nation to ratify it. Notably, the United States remains one of the few countries that has not ratified the treaty, despite its significance in regulating maritime affairs.
UNCLOS has shaped international maritime law by establishing a framework for countries to manage marine resources sustainably. Its provisions have contributed to protecting marine life and curbing pollution.
The treaty’s implementation is carried out by the nations party to it, rather than by the United Nations Secretariat, which provides administrative support—such as receiving instruments of ratification and accession and facilitating meetings of states parties—but holds no direct operational role. The UN secretary-general has promoted the treaty and encouraged ratification. In 2023, a major development emerged with the agreement on a High Seas Treaty, designed as an additional instrument under UNCLOS.
This accord aims to safeguard ocean life in international waters through measures including marine protected areas and environmental impact assessments. The High Seas Treaty demonstrates the capacity of nations to collaborate on shared challenges and underscores the value of international cooperation in ocean protection.
The widespread adoption of UNCLOS reflects the importance of collective action in preserving marine ecosystems. Its provisions have advanced responsible use of ocean resources and provided a structure for sustainable management. Looking forward, the implementation of the High Seas Treaty will be a key factor in addressing threats to marine biodiversity in areas beyond national jurisdiction.
As countries continue efforts to protect the oceans, UNCLOS is expected to remain central to promoting responsible resource use and ensuring the health of marine environments for future generations. With its extensive ratification and the addition of the High Seas Treaty, the convention is positioned to play a continuing role in global ocean governance, with effects likely to be observed for years to come.
