For the first time, United Nations (UN) members have agreed on a unified treaty to protect biodiversity in the high seas. The treaty agreement concluded two weeks of talks in New York.

An updated framework to protect marine life in the regions outside national boundary waters, known as the high seas, had been in discussions for more than 20 years, but previous efforts to reach an agreement had repeatedly stalled. The unified agreement treaty, which applies to nearly half the planet’s surface, was reached late Saturday.

Nichola Clark, an oceans expert at the Pew Charitable Trusts who observed the talks in New York, called the long-awaited treaty text “a once-in-a-generation opportunity to protect the oceans — a major win for biodiversity”.

The treaty will create a new body to manage conservation of ocean life and establish marine protected areas in the high seas. Ms. Clark said that is critical to achieve the UN Biodiversity Conference’s pledge to protect 30% of the planet’s waters, as well as its land, for conservation.

The crafting of the treaty represents “a historic and overwhelming success for international marine protection”, said Steffi Lemke, Germany's Environment Minister.

“For the first time, we are getting a binding agreement for the high seas, which until now have hardly been protected,” Ms. Lemke said. “Comprehensive protection of endangered species and habitats is now finally possible on more than 40% of the Earth’s surface.” The treaty also establishes ground rules for conducting environmental impact assessments for commercial activities in the oceans.

“It means all activities planned for the high seas need to be looked at, though not all will go through a full assessment,” said Jessica Battle, an oceans governance expert at the Worldwide Fund for Nature. “This treaty will help to knit together the different regional treaties to be able to address threats and concerns across species’ ranges,” Ms. Battle said.