Earth's Oceans Are Rapidly Losing Oxygen

Supplies of dissolved oxygen in bodies of water across the globe are dwindling rapidly, and scientists say it's one of the greatest risks to Earth's life support system.

• Importance of Dissolved Oxygen (DO): Supplies of dissolved oxygen in global water bodies are rapidly dwindling, posing a major risk to Earth's life support system. Just as atmospheric oxygen is vital for terrestrial animals, DO is essential for healthy aquatic ecosystems.Billions rely on marine and freshwater habitats for food and income, making the decline in DO concerning.

• Proposed Addition to Planetary Boundaries: Scientists propose adding aquatic deoxygenation to the 'planetary boundaries' framework, which outlines thresholds for humanity's sustainable development.

• Critical Oxygen Thresholds: DO depletion is approaching critical thresholds comparable to other planetary boundary processes. Factors include warmer waters holding less DO, algal blooms, bacterial booms, and increased density differences between water layers.

• Eutrophication: Severe DO depletion leads to eutrophication, where oxygen-dependent organisms die, and oxygen-independent microbes dominate, creating a vicious cycle.

• Call to Action: The paper's authors urge global efforts to monitor and research aquatic deoxygenation and to implement policies to prevent rapid deoxygenation.

• Possible Mitigation Strategies: Reduce nitrogren nutrient runoff and organic carbon inputs can slow or reverse deoxygenation.

Resource:

https://www.sciencealert.com/earths-water-is-rapidly-losing-oxygen-and-the-danger-is-huge