September 2025: A historic win for the ocean, new reports raise alarm on ocean health, and the discovery of coral 'chewbacca'.

Here's our round-up of some of this month's ocean science news!

It's historic: the BBNJ Agreement will come into force in January 2026.

The landmark BBNJ Agreement, also called 'High Seas Treaty', provides a framework to better protect the ocean that is outside of national boundaries — and which covers two-thirds of the ocean, or half of the Earth's surface.

After two decades of negotiations, the treaty met the threshold for its entry into force on 19 September, when Morocco and Sierra Leone became the 60th and 61st countries to ratify it.

This milestone is just the beginning. As more countries sign and ratify the treaty, and policymakers and scientists work on its implementation, the BBNJ can usher in a new era of ocean protection, rooted in science and global cooperation — and the framework of the Ocean Decade is a key foundation for its implementation. Read more here.

Two new major publications raise the alarm on the state of the ocean.

The 2025 Planetary Health Chuck, published on 24 September by PIK - Potsdam Institute for Climate Impact Research , finds that, for the first time, the Planetary Boundary for ocean acidification has been breached — highlighting that "the ocean is turning more acidic, threatening marine life as we cross into unsafe conditions with a worsening trend." The report concludes that seven out of nine Planetary Boundaries have been breached, with all of those seven showing trends of increasing pressure, suggesting further deterioration and destabilization of planetary health in the near future.

The 9th Ocean State Report, published on 30 September by Copernicus Marine Service , reports that no part of the ocean is untouched by the ‘triple planetary crisis’ of climate change, biodiversity loss, and pollution. Detailing changes in the global ocean and European regional seas, with a focus on 2023 and 2024, this year's report emphasises that when the ocean changes, so does everything connected to it: marine ecosystems, society, and the economy.

Researchers discover a new 'hairy' species of deep-sea coral — and name it after Star Wars' 'Chewbacca'.

First spotted in 2006 off Moloka’i island in Hawai’i, and in 2016 near the Mariana Trench, this deep-sea coral has now formally been recognised as a new species named Iridogorgia chewbacca. Living in the tropical Western Pacific, this coral is known for its long, flexible branches and shiny surface.

Les Watling, professor emeritus in University of Hawai’i Mānoa’s School of Life Sciences and co-author of the study establishing this new species, said: "Seeing this coral for the first time was unforgettable. Its long, flexible branches and shape immediately reminded me of Chewbacca. Even after years of deep-sea work, discoveries like this still make me stop and take notice.” Read more here.