New global agreement on the protection and sustainable use of resources and biodiversity in the high seas


On 4 March 2023, at an inter-governmental conference in New York, negotiations between the representatives of more than 100 countries culminated in the adoption of an international agreement on the conservation and the sustainable use of marine biological diversity of areas beyond national jurisdiction, also referred to as the UN Treaty of the High Seas (the “Treaty”). The unedited draft is available on the UN website.


The Treaty takes the form of a new implementing agreement under the United Nations Convention on the Law of the Sea (“UNCLOS”). UNCLOS is the main international instrument governing the rights and obligations of states in relation to the use of the world’s oceans and seas. While UNCLOS contains some high-level provisions on the conservation and management of the living resources of the high seas and of the seabed and ocean floor beyond the limits of national jurisdiction, these are limited in their scope and extent. Nearly two-thirds of the ocean is beyond national jurisdiction and under increasing pressure from pollution, overexploitation, climate change and decreasing biodiversity. The Treaty is seen as an essential step in the global efforts to counter the destructive trends facing the world’s oceans today.

Further, the Treaty is perceived as vital for achieving the target set by the Kunming-Montreal Global biodiversity framework to protect 30% of the global oceans by 2030.

The Treaty

The stated general objective of the Treaty is to “ensure the conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction” through effective implementation of the provisions of UNCLOS and via further international cooperation and coordination.

Chapter I enshrines established principles such as polluter-pays, the use of best available science, common heritage of mankind and the precautionary approach, the principles of freedom of the high seas and of marine scientific research and the fair and equitable sharing of benefits. The Treaty seeks to strike a balance between scientific goals and environmental protection.

Chapter II is dedicated to the exploitation of marine genetic resources and the fair and equitable sharing of benefits derived from them. In summary, the Treaty allows all parties to engage in activities in respect of marine genetic resources beyond national jurisdiction, so long as they are carried out in accordance with the provisions of the Treaty. A key requirement is for the notification of activities to a “clearing-house mechanism” established by the Treaty, which is a digital open-access platform for the sharing of information. The Treaty requires non-monetary benefits of such activities (samples, scientific data, marine technology and capacity building) to be shared in a fair and equitable manner; as well as that the monetary benefits (including their commercialisation) are also shared fairly and equitably under a financial mechanism set up by the Treaty whose modalities are to be finalised. 

Chapter III provides for the establishment of “area-based management tools” including marine protected areas, following proposals submitted by states (individually or collectively) to the Treaty’s Secretariat. The proposals are to be made public, subject to consultation with stakeholders, and to be reviewed by the Scientific and Technical Body established by the Treaty. At the end of the process, proposals are voted on by the Conference of the Parties (“COP”) to the Treaty, with a consensus (unanimity) being required to adopt them, or, where efforts to reach an agreement by consensus have been exhausted, by a three-quarter majority of the parties present and voting. It is this mechanism which is lauded as a key tool for the protection of the ocean/marine environment.

Chapter IV introduces the requirement to conduct an environmental impact assessment of planned activities under states’ jurisdiction or control before engaging in the activities. The Treaty establishes minimum criteria for the content of assessment reports and requires them to be filed with the clearing-house mechanism. While a process of consultations is envisaged, it is the ultimately the state that engages in the relevant activity which decides whether to proceed.

Chapter V comprises provisions for capacity building and transfer of marine technology.

The last three chapters of the Treaty are dedicated to institutional arrangements, financial resources, implementation and compliance, settlement of disputes and miscellaneous provisions. Importantly, a compliance body is established by the Treaty, although its function is merely facilitative, and it does not have the power to impose penalties or make findings of non-compliance. The dispute resolution procedure under the Treaty gives parties freedom of choice to settle disputes by any peaceful means.

Next steps

The Treaty will not enter into force until the 120th day after its ratification by a minimum of sixty state parties. There is a similar provision in the UNCLOS which delayed its entry into force until nearly twelve years from the date of its adoption.


The Treaty has been hailed as a major success by the President of the UN General Assembly, the President of the EU Commission, the spokesperson for the Secretary General of the UN and various influential intergovernmental organisations and NGOs.

UNCLOS did not reach the ratification threshold required for its entry into force in the first decade from its formal adoption. The role of the world’s oceans in the climate emergency, reversing biodiversity loss and the need to tackle pollution is expected to prompt states to act quicker in ratifying the Treaty. The EU have stated that it will work to ensure this happens rapidly and to help developing countries prepare for its implementation. The EU has pledged €40 million as part of a Global Ocean Programme and has invited members of the High Ambition Coalition (totalling 52 countries) to do the same within their capabilities.

Once in force, the Treaty process for considering and voting on all proposals on marine protected areas requires unanimity or a qualified majority of 75% of votes, if a two-thirds majority of the COP determines that the efforts to reach a consensus have been exhausted.

Finally, some scope for unilateralism is embedded in the Treaty, with the prime examples being that the ultimate decision on whether to proceed with proposed activities once an environmental impact assessment has been conducted rests with the state proposing them; and parties may object to decisions of the COP on various grounds with the effect that the decisions are not treated as binding on that state party.

Article co-authored by Sofia Sotgia, Trainee Solicitor at CMS.