Dozens of nations are set Wednesday to sign a historic treaty on protecting the high seas, seeking the quick entry into force of an accord designed to protect ecosystems vital to the planet.
The United Nations in July sealed the first treaty on the high seas after 15 years of discussion.
The start of signatures, during the annual UN General Assembly, "represents an important step to establishing meaningful protections," said Nichola Clark of the Ocean Governance Project of The Pew Charitable Trusts.
"We begin a new chapter where the global community must take bold action in order to realize those protections, and ensure the ocean's enormous reservoirs of biodiversity continue to provide benefits for ocean health and the communities across the globe that depend on it," she said.
The text of the treaty was formally adopted by consensus even though Russia said that parts of it were unacceptable.
The high seas start beyond countries' exclusive economic zones, or 200 nautical miles (370 kilometers) off coastlines — covering nearly half the planet.
Nonetheless, they have long been ignored in discussions on the environment.
A key tool in the treaty will be the ability to create protected marine areas in international waters — only around one percent of which are now protected by any sort of conservation measures.
The treaty is seen as crucial to an agreement to protect 30 percent of the world's oceans and lands by 2030, as agreed by governments in a separate historic accord on biodiversity reached in Montreal in December.
'Race to ratification'
The treaty will come into force 120 days after 60 countries ratify it.
According to the United Nations, more than 60 governments plan to initial the treaty starting Wednesday. But formal ratification depends on each country's own domestic process.
Mads Christensen, interim executive director of Greenpeace International, voiced hope that the treaty would come into force in 2025, when the next UN oceans conference takes place in France.
"We have less than seven years to protect 30 percent of the oceans. There is no time to waste," he said.
"The race to ratification has begun and we urge countries to be ambitious, ratify the treaty and make sure it enters into force in 2025."
But even if the treaty draws the 60 ratifications needed to come into force, it would still be well below the universal support for action sought by environmental defenders.
Oceans are critical for the health of the whole planet, protecting often microscopic biodiversity that supports half of the oxygen breathed by land life. The oceans are also critical to limiting climate change by helping absorb greenhouse gas emissions.
The treaty, officially known as the treaty on "Biodiversity Beyond National Jurisdiction" or BBNJ, also introduces requirements to carry out environmental impact studies for proposed activities on the high seas.
Such activities, while not listed in the text, would include anything from fishing and maritime transport to more controversial pursuits such as deep-sea mining or even geo-engineering programs aimed at fighting global warming.