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Rising Concerns

Scientists highlight the critical issue of depleting dissolved oxygen in water bodies worldwide, posing a significant threat to life on Earth.

Importance of Dissolved Oxygen

Just as atmospheric oxygen is vital for terrestrial animals, dissolved oxygen (DO) is crucial for maintaining healthy marine and freshwater ecosystems.

Impact on Human Livelihoods

The decline in oxygen levels in aquatic habitats is alarming, especially since billions of people rely on these ecosystems for food and income.

Proposal for Planetary Boundaries

A team of scientists suggests adding aquatic deoxygenation to the list of ‘planetary boundaries,’ which currently includes nine domains essential for sustainable human development.

Current Planetary Boundaries

The existing boundaries cover climate change, ocean acidification, stratospheric ozone depletion, phosphorus and nitrogen cycles, biodiversity loss, freshwater use, land-system change, aerosol loading, and chemical pollution.

Research Findings

Led by freshwater ecologist Kevin Rose from Rensselaer Polytechnic Institute, the team argues that the deoxygenation of Earth’s aquatic ecosystems is a critical process that regulates and responds to other planetary boundary processes.

Causes of Oxygen Depletion

Warmer water temperatures, resulting from increased greenhouse gas emissions, reduce the water’s capacity to hold dissolved oxygen. Algal blooms and bacterial booms, driven by organic matter and nutrients from sewage, industrial waste, and fertilizers, also consume significant amounts of oxygen.

Consequences for Aquatic Life

The depletion of dissolved oxygen can lead to the suffocation and death of microbes and other aquatic organisms, disrupting the ecological balance.

Urgency for Action

The study underscores the need to address the deoxygenation of aquatic environments urgently, as critical oxygen thresholds are being approached at rates similar to other planetary boundary processes.