The loss of sea ice over the last two decades has triggered an irreversible chemical shift in the Arctic Ocean. By exposing shallow coastal waters to intense sunlight, the melting ice has accelerated a process that destroys nitrate, the foundational fertiliser required for marine life to survive.
Based on a paper in Nature Communications and a report in The Guardian 19 January 2026
Scientists report that global floating seaweed blooms are expanding in the oceans, with possible serious consequences. In the past two decades, both microscopic algae, such as phytoplankton, and seaweeds or macroalgae, have increased in certain coastal and open ocean waters.
Two important agreements for the protection of the oceans and their living resources have now come into force: the High Seas Treaty, and the WTO Fisheries Subsidies Agreement.
High Seas Treaty
The ocean makes up nearly 70% of the planet’s surface, but beyond national exclusive economic zones, much of the ocean is the High Seas, thus no one's responsibility.
The collapse of a critical Atlantic current can no longer be considered a low-likelihood event, new research has concluded, making deep cuts to fossil fuel emissions even more urgent to avoid the catastrophic impact.
“We close this historic week not just with hope, but with concrete commitment, clear direction, and undeniable momentum,” Li Junhua, the UN’s Under-Secretary-General for Economic and Social Affairs and Secretary-General of the summit, told reporters.
The latest review of planetary boundaries in 2023 showed that six of the nine boundaries had been crossed. Now a seventh planetary boundary has been breached: ocean acidification. The health of the oceans is worse than previously thought, and we are running out of time to protect marine ecosystems.
