The University of St. Andrews (United Kingdom) published research in the journal Nature Communications that warns of a concerning phenomenon: ocean acidity is advancing much faster than anticipated, especially in coastal areas with upwelling.
“Some coastal areas will become much more acidic than previously thought,” the scientists noted, highlighting that this process directly threatens marine biodiversity and the economy of the communities that depend on it.
What is upwelling and why does it accelerate ocean acidity?
Upwelling is a natural process in which deep, cold waters rise near the coast, bringing with them nutrients… and also high levels of acidity.
- These waters already contain carbon dioxide (CO₂) accumulated on the seabed.
- When mixed with atmospheric CO₂, the acidity intensifies.
- The decomposition of organisms on the seabed releases more CO₂, which adds to the process.
- Upon reaching the surface, the water absorbs even more carbon dioxide from the air.
The result is a cycle of accelerated acidification, making upwelling systems key points to understand climate change.
Scientific evidence: corals and boron isotopes
The St. Andrews team analyzed the marine past through ancient coral samples, whose skeletons record the ocean’s chemical history. They also used boron isotopes to measure acidity over time.
By comparing these data with simulations, they detected that in regions with upwelling, acidity increases faster than in areas influenced solely by atmospheric CO₂.
Notable examples:
- California Current (USA)
- Humboldt Current (Peru)
- Benguela Current (West Africa)
- Canary Current (Northeast Atlantic)
In all of them, the change is felt more intensely, putting both biodiversity and the local economy at risk.
Impacts on biodiversity and communities
Ocean acidification directly affects fish, mollusks, and species that sustain the food chain. This threatens artisanal fishing, food supply, and the livelihoods of millions of families.
Researchers warn that the forecast is complex: human influences mix with natural sources of acidity, making it difficult to predict how upwelling systems will respond to climate change.
The ocean as a climate regulator
Beyond biodiversity, oceans perform vital functions for the planet:
Climate regulation
- Heat and carbon sink: they absorb a large part of atmospheric CO₂ and heat.
- Water cycle control: they regulate atmospheric circulation and the formation of clouds and precipitation.
Health of marine ecosystems
- Oxygen availability: cold waters carry more oxygen, essential for marine life.
- Productivity and nutrients: warm surface waters facilitate the transport of nutrients to areas of high productivity.
- Biodiversity: sensitive ecosystems like coral reefs suffer irreversible damage from excessive warming.
Prevention of extreme events
- Stronger storms: the increase in sea temperature intensifies hurricanes and cyclones.
- Ocean acidification: excess CO₂ can lead to the extinction of species unable to adapt.
Solutions and everyday actions
The fate of the coasts does not depend solely on science but also on daily actions. Green technologies like electric vehicles or heat pumps help reduce CO₂ emissions, slowing ocean acidification.
Every technological advance directly impacts the oceans, which act as the planet’s global thermometer. When the sea becomes more acidic, the alert is not just for scientists: it is a call for the entire society.
Accelerated acidification in upwelling areas is a clear signal that climate change affects both ecosystems and human communities. Protecting currents like California, Humboldt, Benguela, and Canary is key to preserving biodiversity, jobs, and the food supply for millions of people.
The ocean reminds us that caring for the environment is a shared task: preventing greater damage to marine life is everyone’s responsibility.
