The annual Copernicus program report sounds the alarm. Rising sea levels, rapid melting of sea ice, the spread of invasive species, and unprecedented increases in marine heatwaves pose a serious threat to international food security, the economic system, coastal populations, and ecosystems.
The origins of oceanography
The first oceanographic studies date back to the time of navigator James Cook in the 18th century. Later, the 1,290-day voyage of the HMS Challenger collected a wealth of data on ocean physics, including salinity, temperature, and seawater density.
The first studies on ocean acidification and its effects on marine ecosystems appeared at the end of the 20th century. Since the 2000s, this topic has become central in environmental science and climate research. This is why, since 2015, the European Copernicus program has published an annual report to monitor changes in the world’s oceans.
Ocean acidification: a key indicator of the marine climate crisis in the Copernicus 2025 report
Acidification in oceanography is characterized by a gradual decrease in water pH. It results from the absorption of CO2 released by human activities such as transportation, deforestation, and industry. The 2025 Copernicus report is cause for serious concern. Increasing acidification, ocean warming, and climate change represent a real climate crisis for marine life and biodiversity.
Scientific studies report that in April 2024, the average surface temperature of the ocean reached a record 21 degrees Celsius. In 2023, the Atlantic regions experienced more than 300 days of marine heatwaves. Rising sea levels and climate change are leading to a scarcity of fresh water and soil salinization. This will affect flora, fauna and human activities such as fishing and tourism.
In short, immediate and decisive action is essential. Only strict climate protection measures can keep the risks at a tolerable level.
The critical state of marine environments: challenges and urgent action to preserve biodiversity
Pierre Bahurel, Director General of Mercator Ocean International, said : “The Ninth Copernicus Ocean State Report confirms that we are dangerously approaching planetary boundaries. Every part of the ocean is now affected by the triple planetary crisis. In such a context, we need reliable science and operational tools more than ever” (Copernicus Marine Service Press Release, 30 September 2025).
Flora such as seagrass beds will soon become endangered species. This will lead to a decline in biodiversity and degradation of marine habitats. If temperatures continue to rise, marine fauna could decline sharply in the coming years. Warm water would disrupt reproduction and reduce the oxygen. Ultimately, some species may migrate due to changing conditions. New invasive species can impact ecosystems at multiple levels.
The Copernicus 2025 report describes an alarming situation for the oceans. Scientists can closely monitor these developments and warn of future risks.
For more information, click here: https://marine.copernicus.eu/osr9-summary/flipbook/
Keywords: Oceans, Climate change, Biodiversity, Marine ecosystems.
