Deep into overtime, exhausted delegates to a conference at the United Nations' headquarters in New York sealed a deal to create a global network of marine protected areas covering 30% of the world's oceans by 2030.
It's a target scientists say is needed to preserve the rich diversity of marine species' health and to mitigate the rising impacts of climate change.
The international legally binding instrument – which must be formally adopted by countries before it can take effect – updates the U.N. Convention on the Law of the Sea, or UNCLOS, which came into force in 1994.
The new High Seas Treaty for the first time provides a legal framework and creates a new entity to conserve and sustainably use marine biological diversity in areas no country can claim.
"What happens on the high seas will no longer be 'out of sight, out of mind,' " said Jessica Battle, a senior global ocean governance and policy expert for WWF International who led its negotiating team at the conference.
The new treaty "will allow for the kind of oversight and integration we need if we want the ocean to keep providing the social, economic and environmental benefits humanity currently enjoys," she said.
Negotiators from among 193 U.N. member nations reached agreement late Saturday night, after a marathon session that went all night and extended the scheduled end of the 12-day conference for more than a day longer.
They put aside their differences over key substantive issues on how to protect open oceans' rich biodiversity from commercial pressures to form a new treaty, which has been almost two decades in the making.
"Ladies and gentlemen, the ship has reached the shore," said the conference's president, Rena Lee, in announcing that negotiators had finally succeeded.
Lee, who is Singapore’s ambassador for oceans and special envoy of the foreign minister, clasped her head in emotion and fatigue as delegates stood and wildly applauded, then said there was more work to do and everyone sat down.
"We have finished the text of the agreement," she added. "We will run through the text for technical edits, the text will then be translated into all six language versions. Time to be specified, we will formally adopt the text in all six official languages of the United Nations."
The treaty is intended to strengthen marine protections on the high seas, those international waters beyond the 200 nautical mile (370 kilometer) jurisdiction of coastal nations.
No universal law exists to protect marine species and minerals in high seas that account for nearly 64% of ocean waters, or 43% of Earth's surface. This treaty, which will still require formal ratification, stands to change all that.
"This is a massive success for multilateralism. An example of the transformation our world needs and the people we serve demand," said U.N. General Assembly President Csaba Kőrösi.
Marine genetic resources a key sticking point
U.N. member nations began discussing the idea of a high seas treaty in 2004, leading to talks every couple years.
It wasn't until December 2017, however, that the U.N. General Assembly formally agreed that an international conference was needed to hammer out a high seas treaty based on Article 192 of UNCLOS, which says nations "have the obligation to protect and preserve the marine environment."
The first round of negotiations in Sept. 2018 was followed by two more rounds in March and August 2019. The fourth round, postponed due to the COVID-19 pandemic, came in March 2022. The fifth round was held in August of that year, but was suspended – only to be resumed this month.
UNCLOS created three new international organizations to manage ocean resources: the International Tribunal for the Law of the Sea in Hamburg, Germany; International Seabed Authority in Kingston, Jamaica; and Commission on the Limits of the Continental Shelf in U.N. headquarters at New York.
Since those apply only within nations' jurisdictions, this new treaty would extend UNCLOS by requiring sustainable uses of marine biological diversity beyond national borders. Its significance lies in formally evaluating how fish stocks, marine genetics and other resources should be globally administered, conserved and sustained.
One of the last hurdles, however, has been finding agreement on how to equitably share the valuable marine genetic resources that require technological know-how to retrieve.
That included questions on the approval process, once an environmental impact assessment is made, and how to handle concerns. Previous negotiations failed to find common ground between rich and developing nations on the rules for assessing commercial enterprises.
Some insisted that the treaty should also include references to a common heritage of "humankind” and the freedom of the high seas, the Intergovernmental Conference on Marine Biodiversity, which runs the conference, reported.
Lee noted that delegates agreed the environmental impact assessments should be led by governments "in order to promote transparency," but there are provisions for others with an interest in the process to offer "non-binding recommendations."
This story has been updated with additional details.