- The agreement on marine biodiversity of areas beyond national jurisdiction, also known as the high seas treaty, was reached in 2023 with much fanfare in marine conservation circles, partly because it sets up a system for establishing marine protected areas (MPAs) in international waters.
- On Sept. 19, Morocco became the 60th country to ratify the deal, which means it will become binding international law in January 2026.
- Experts and advocates celebrated the milestone, calling it a win for conservation and international cooperation.
- Uncertainty remains in how the treaty will interact with other regulatory regimes for fishing and mining, among other activities.
A major treaty establishing a framework for the world’s nations to jointly manage marine conservation in international waters, which cover about half of the Earth’s surface, has reached enough ratifications to become international law. It will come into force in January.
The deal, known as the agreement on the conservation and sustainable use of marine biological diversity of areas beyond national jurisdiction (BBNJ), was reached in 2023 with much fanfare in marine conservation circles. But like any international agreement, the high seas treaty, as it’s often called, didn’t just become law overnight. It required 60 countries to ratify it to enter into force. Now, with unusual speed by the standards of such deals, it’s reached that threshold.
Morocco deposited its instrument of acceptance on Sept. 19, becoming the 60th country to do so. That launched a 120-day period until the treaty will become binding international law, on Jan. 17, 2026. Experts and advocates celebrated the occasion, calling it a win for conservation and international cooperation.
“This is a super big deal, both for ocean protection and for proving that there’s still hope in multilateralism, that countries can come together and do big things, even in these times where there’s so much discord across the world,” Arlo Hemphill, an oceans project lead at Greenpeace USA, told Mongabay.
Morocco’s mission to the U.N. called it “a milestone for the protection of the ocean, the strengthening of multilateralism, and the collective commitment of the international community to safeguarding marine biodiversity beyond national jurisdiction” in an X post.
Phillianne Ernesta, an official in the fishing ministry of the Seychelles, an archipelagic nation in the Indian Ocean, also hailed the achievement and her country’s role as an early ratifier of BBNJ. “We are proud to contribute to a treaty that will strengthen conservation, advance scientific research, and support sustainable blue economy opportunities for present and future generations,” Ernesta said in a statement.
A coming MPA boom?
The high seas, far from being the barren expanse they were once thought to be, contain richly biodiverse ecosystems, including deep-sea coral and sponge fields, deep trenches, sulphurous vents and underwater mountains known as seamounts. The vast ocean also regulates the Earth’s systems, including the climate. Yet today it faces an array of threats including pollution, overfishing and biodiversity loss.
Discussions on a treaty to fill governance gaps in the high seas began in the 2000s, with formal negotiations starting in 2018. U.N. member states finalized the treaty text after arduous negotiations in March 2023 and formally adopted it in June 2023; 145 of the 197 U.N. member countries signed the treaty before the two-year signing period closed on Sept. 20 of this year. The treaty applies to all of the ocean that is outside of countries’ exclusive economic zones (EEZs), which generally extend 200 nautical miles (370 kilometers or 230 miles) from coastlines.
The treaty has four main components: It sets standards for environmental impact assessments for resource extraction, offshore wind and other projects. It establishes rules for exploration and exploitation of marine genetic resources, such as can be used in medicines and cosmetics; this was the most fiercely negotiated part of the treaty, with low-income nations seeking to ensure they would benefit even if they didn’t have the capacity to develop the resources themselves. It facilitates capacity building for and transfer of technology to low-income countries so they can take part in oceans projects. And it sets up a system for the development of high seas marine protected areas (MPAs), a longstanding goal of conservationists.
In a 2022 international agreement, the Kunming-Montreal Global Biodiversity Framework, the world’s nations agreed to protect 30% of both land and sea by 2030 — “30×30,” as the initiative is known. The new high seas treaty doesn’t mention 30×30, but it makes the target achievable, experts say.
“There is no possibility that we can do that for the ocean without the high seas being included,” Callum Roberts, a professor of marine conservation at the University of Exeter in the U.K., told Mongabay. “Fundamentally, we’ve got to have this instrument to be able to achieve 30×30, period.”
Less than 1.5% of the high seas is currently protected, according to Protected Planet, a protected areas database. The first MPAs could be established under the treaty in late 2028 or 2029, experts say, given the lengthy nature of the process.
The High Seas Alliance, an umbrella group of NGOs, has already identified eight possible high seas MPAs, including one protecting the Salas y Gómez and Nazca ridges, seamount ranges that dip into Chilean and Peruvian waters. Chile has spearheaded early efforts to promote the MPA in discussions with parties to the South Pacific Regional Fisheries Management Organisation (SPRFMO).
One matter that’s long been contentious in BBNJ negotiations and remains only partly settled is what role regional fisheries management organizations (RFMOs) such as SPRFMO will play in the MPA designation process. RFMOs are multilateral bodies that manage fish stocks in the high seas.
The treaty is worded such that RFMOs’ authority must be respected but they don’t necessarily have veto power over the development of new MPAs. How the rules will be interpreted and how cooperation with RFMOs will function in practice remains to be worked out, experts say.
Roberts said language somewhat limiting the power of RFMOs to prevent MPA designations was inserted “because there was a widespread feeling that they [the RFMOs] might want to block those protected areas being created.” He said relying on RFMOs to take conservation action would be a mistake, as they’ve caused “major impacts on wildlife and habitats” and their “inadequacies” were a main reason the high seas treaty was needed.
Questions also remain about how the high seas treaty will interact with other multilateral institutions besides RFMOs, most notably the International Seabed Authority (ISA), a U.N.-affiliated body that regulates deep-sea mining. The ISA is still establishing rules for commercial exploitation but has rules for exploration in place. The environmental impact assessment standards set forth in the high seas treaty could add a layer of stringency to ISA rules, if they’re interpreted to apply to deep-sea mining.
Looking ahead
Some international agreements remain mired in the ratification process for many years. For example, the World Trade Organization’s agreement to curb fisheries subsidies was 24 years in the making and also managed to reach the required ratifications to enter into force this month. Some agreements never complete the process at all. By contrast, the high seas treaty will enter into force with “remarkable” speed for a treaty of its “scope and impact,” Nichola Clark, a senior officer with The Pew Charitable Trusts, a U.S.-based think tank, said in a statement following the 60th ratification.
Ratification is done at the national level, usually with the approval of a legislature. Conservationists and proponents of the treaty are not satisfied with 60, or even 63, the number of ratifications at the time of this story’s publication: They’re pushing for universal ratification.
“The more countries that are on any treaty, the stronger it is,” Hemphill of Greenpeace said.
Countries that haven’t ratified aren’t bound by the treaty. Those that signed but haven’t ratified do have a limited responsibility not to undermine the treaty’s aims, per preexisting international treaty law. Countries do have an incentive to ratify: Only those that do so will be able to vote on decisions at the conferences of the parties (COPs).
Treaty-watchers view the U.S. as an important outlier. Under former President Joe Biden, the country was a key player in the negotiations over the text, but the administration of current President Donald Trump has retreated from global oceans leadership and the U.S. didn’t send a delegation to the two BBNJ preparatory meetings held in New York this year. The Trump administration hasn’t publicly indicated that it won’t ratify BBNJ, but its approach to the institution remains unclear. The U.S. State Department didn’t provide answers to questions posed for this article.
The first COP must be held within one year of the treaty entering into force on Jan.17, 2026. It’s not yet clear which country will house the BBNJ secretariat; Belgium and Chile are both vying to do so.
Many of the treaty’s rules of procedure remain to be worked out. One key point of contention is the level of access that observers, such as from NGOs, Indigenous groups or even representatives of other multilateral bodies, will have at meetings. Some countries want a rule allowing any one country to veto an application for observation, a prospect that’s not popular with NGOs. Such a rule would “undermine transparency and run counter to the Treaty text, which explicitly requires that participation ‘shall not be unduly restrictive,’” according to a statement from the High Seas Alliance.
Banner image: An oceanic whitetip shark (Carcharhinus longimanus) with pilot fish (Naucrates ductor). Image courtesy of Renata Romeo/Ocean Image Bank.
As U.N. members clinch historic high seas biodiversity treaty, what’s in it?
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