High Seas Treaty Reaches 100 Parties as Six More Nations Ratify at the UN

The UN’s High Seas Treaty passed its 100th ratification on 23 September 2026, after Germany, Canada, Australia, Papua New Guinea, Zimbabwe and Brunei Darussalam deposited their instruments of ratification during UN General Assembly high-level week in New York. The milestone came as part of the UN’s annual Treaty Event, held this year under the banner “Promoting multilateral treaties – safeguarding humanity” from 22 to 25 September at UN Headquarters, when member states are invited to sign or ratify treaties deposited with the Secretary-General.

The first global rulebook for the open ocean

Formally known as the Agreement on Biodiversity Beyond National Jurisdiction, the treaty is described by advocates as the world’s first comprehensive legal framework for protecting marine life on the high seas, the roughly two-thirds of the ocean that lies outside any country’s national waters. It sets out procedures for establishing marine protected areas, environmental impact assessments for activities on the high seas, and the sharing of benefits from marine genetic resources. The treaty entered into force on 17 January 2026, almost two decades after negotiations first began, and its first Conference of the Parties is scheduled for January 2027 to settle institutional rules and priorities.

Momentum beyond the wealthiest states

Rebecca Hubbard, director of the High Seas Alliance, said “the number 100 marks real momentum for ocean protection, even in divided times,” while cautioning that “we cannot stop here” if the treaty is to deliver equitable global ocean protection by 2030. Advocates highlighted that the treaty’s membership spans wealthy maritime powers alongside small island states, developing countries and even landlocked nations. Dr Aristide Takoukam Kamla of the African Marine Conservation Organisation said that for coastal communities in Central and West Africa, “a protected high seas means healthier fisheries, thriving marine wildlife and a more secure future.”

Why it matters

Crossing 100 parties gives the treaty a critical mass of support heading into its first formal meeting of members, but campaigners say the real test will be whether governments follow through with actual protected areas once the rulebook is in place. With the ocean absorbing a large share of the impacts of climate change and biodiversity loss, the pace of ratification by both large and small states will shape how quickly enforceable protections can be put in place beyond national coastlines.