The ocean acidification data gap

In 2025, the Potsdam Institute for Climate Impact Research determined that the ocean acidification planetary boundary had been breached for the first time, degrading the ocean’s ability to stabilise the global climate and pushing humanity and marine life beyond the agreed safe zone.

The ocean absorbs at least a quarter of the carbon dioxide released into the atmosphere, driving chemical changes that visibly affect marine life and ocean chemistry. Yet despite decades of research, a fundamental question remains difficult to answer: how exactly is ocean acidification changing marine ecosystems?

The Global Ocean Acidification Observing Network (GOA-ON)’s Biology Working Group has worked for years to demonstrate the real-world biological impacts of ocean acidification. Alongside observations and experience from marine communities, abundant evidence from laboratory experiments shows how different organisms respond to acidification. Coral reefs have eroded, lost biodiversity and become overgrown with algae; acidification is known to make it more difficult and energetically demanding for calcifying organisms, such as corals and shellfish, to grow and maintain their normal structures. What’s missing, however, is substantial long-term, quantifiable data to connect those responses to what is happening to the chemistry of seawater across the entire ocean.