Photo of beach in Nice, France, by Amira El Fohail
At the third UN Ocean Conference (UNOC) in Nice, held from 9th – 13th June 2025 and co‑hosted by France and Costa Rica, governments, heads of state and more than 10,000 delegates, including 60 world leaders, gathered to confront an ocean in crisis. Against a backdrop of soaring marine heat, acidification and rising sea levels, they launched the “Nice Ocean Action Plan,” ratcheted up momentum on the High Seas Treaty—and secured billions in financial pledges aimed at bolstering biodiversity, curbing plastic pollution, and protecting fragile coastal and high‑seas ecosystems.
High Seas Treaty ratifications
A significant wave of new ratifications brought the 2023 High Seas Treaty—formally the Biodiversity Beyond National Jurisdiction (BBNJ) Agreement—closer to the 60‑country threshold required to bring it into force.
Nineteen nations officially deposited instruments of ratification during the conference, raising the total to 50—just ten short of the necessary 60. Once the threshold is met, the treaty will enter into force after a 120‑day period, marking the creation of a legally binding framework to establish marine protected areas, regulate deep‑sea mining, and promote scientific cooperation across international waters.
French President Emmanuel Macron described the progress as a “win,” noting that several countries—including China, Argentina, and Indonesia—have pledged to ratify soon.
Observers see the developments as a milestone toward protecting marine biodiversity beyond national jurisdictions, though concerns remain about funding and implementation once the treaty takes effect.
Boost for marine protected areas
French Polynesia revealed the creation of the world’s largest MPA by designating its entire Exclusive Economic Zone (EEZ), ~5 million km2, as protected, including 1.1 million km² of highly or fully protected zones—with a further 500,000 km² planned by World Ocean Day 2026.
Chile announced that they will expand the Juan Fernández MPA by approximately 350,000 km², boosting its EEZ protection to over 50%.
Australia announced plans to make nearly a third of its oceans highly protected “no-take” zones by 2030, banning fishing, mining, and drilling in these areas. The move includes reviewing 44 marine parks and ratifying the High Seas Treaty—part of a broader push to boost ocean biodiversity and climate resilience.
The UK Government proposed a major expansion of its ban on bottom trawling, aiming to prohibit the practice in 41 additional MPAs across English offshore waters. This move, if implemented, would increase protected areas from 18,000 km² to 30,000 km²—nearly a quarter of the UK’s MPAs—marking stage three of four of the Marine Management Organisation’s approach to managing fishing in MPAs. The proposal, now under a 12-week public consultation, has been welcomed by environmental groups as a bold step toward meaningful ocean protection, especially ahead of the UN Ocean Conference. However, it faces criticism from the fishing industry and implementation challenges.
Momentum builds against deep-sea mining
In another major announcement, both Macron and Costa Rican President Rodrigo Chaves Robles, confirmed that more than 30 heads of state and government have committed to a moratorium on deep-sea mining—a largely unregulated activity that has drawn widespread concern from scientists and environmentalists.
French President Emmanuel Macron denounced deep‑sea mining as “madness,” calling it a threat to fragile ocean ecosystems. Emphasising the absence of sufficient scientific knowledge and regulatory safeguards, Macron urged nations to support a global moratorium, describing it as an “international necessity”.
“The deep sea cannot become the Wild West,” warned UN Secretary-General António Guterres in a firm statement that underscored the urgency of halting destructive practices before they begin.
Conference closes with call for unity and urgent action
The third United Nations Ocean Conference closed with a strong call for unity and urgent action, as delegates gathered for a final session highlighting the week’s achievements and future commitments. Elinor Hammarskjöld, Special Adviser to the Conference Presidents, delivered the official closing speech, praising the global momentum behind ocean protection and urging nations to turn promises into practice. UN Ocean Envoy Peter Thomson and France’s Special Presidential Envoy for the Ocean, Olivier Poivre d’Arvor, echoed these sentiments, emphasising that the decisions made in Nice must serve as a blueprint for safeguarding marine ecosystems. The conference ended on a note of cautious optimism, with delegates reaffirming their resolve to protect the ocean as a shared global responsibility.