A new review paper led by scientists at UC San Diego’s Scripps Institution of Oceanography warns that the rapid loss of oxygen from aquatic ecosystems is pushing Earth toward an “unsafe space” with potentially irreversible consequences. The study examines the interactions between aquatic deoxygenation—the decline of dissolved oxygen in oceans, coastal waters, rivers, and lakes—and the nine processes outlined by the Planetary Boundaries framework, which identifies critical Earth system processes pushed beyond stable limits by human activities.

Researchers propose adding dissolved oxygen conditions to this framework. "The health and stability of our planet depends on the health and stability of aquatic ecosystems, which need oxygen to function normally," stated lead author Erica Ferrer. Aquatic deoxygenation, driven by warming, nutrient pollution, and changes in water ventilation, disrupts Earth's climate regulation and threatens aquatic life. Even marine mammals can be affected as their prey and habitats are altered.

Ferrer and senior author Lisa Levin aim to elevate aquatic deoxygenation as a global threat. "Adding aquatic deoxygenation to the Planetary Boundaries framework will help us understand its impacts on Earth system stability," Ferrer added. Mitigating these impacts is crucial for maintaining biodiversity and climate stability. The study, published June 30, 2026, in Limnology and Oceanography, involved researchers from various institutions, including UC Santa Barbara and UCLA.