Ocean warming, acidification and sea-level rise are intensifying under the impact of climate change, revealing a triple planetary crisis that threatens both marine ecosystems and coastal societies, according to the 9th Ocean State Report, published on Tuesday 30 September by the European Union’s Copernicus Marine Service.
Ocean heat content (OHC) reached record levels in 2024, with an acceleration of 0.35 ± 0.1 W/m² per decade since the 1960s. Surface temperatures exceeded 21°C on average worldwide in 2023 and 2024, an unprecedented threshold. The average sea level has risen at a record rate of 4.1 ± 0.1 mm/year between 2016 and 2024, an increase of 30% compared with the 1990s. At the same time, the pH of surface waters has fallen by 30% since 1985, endangering sensitive species such as coral and shellfish.
The report indicates that 16% of corals are endangered and that 30% are in a critical situation, exposed to rapid warming or acidification. Marine protected areas (MPAs) currently cover only 8.34% of the oceans, well short of the 30% target to be achieved by 2030.
With regard to pollution, 75% of countries emitting more than 10,000 tonnes of plastic waste are located near threatened coral reefs. Microplastics, produced by the breakdown of this waste, contaminate the food chain and disrupt marine habitats.
Finally, the report reveals that 37.7% of fish stocks are overexploited.
The authors stress the need for greater international cooperation to: extend marine protected areas and reach the target of 30% by 2030; reduce plastic pollution and CO2 emissions, which are responsible for ocean acidification; and improve observation systems in order to better anticipate change and protect vulnerable ecosystems.
Link to the report: https://aeur.eu/f/ioi (Original version in French by Lionel Changeur)