The High Seas Treaty has reached 100 parties after six new ratifications during United Nations General Assembly week. The milestone was confirmed on 23 September.

According to the High Seas Alliance, the treaty entered into force on 17 January 2026. It creates a framework to protect marine life in international waters, which cover nearly two-thirds of the ocean.

The treaty enables the creation of marine protected areas on the high seas and sets rules for environmental impact assessments. Conservation groups called the 100th ratification a historic moment.

The first conference of the parties (COP1) is scheduled for January 2027. Campaigners are now pushing for more nations to join and for strong implementation of the treaty’s protections.

The treaty was adopted in 2023 after years of negotiations. Reaching 100 parties gives it broad backing, as oceans face growing threats from overfishing, pollution and climate change. Ratification campaigns continue in dozens of capitals.