Oxygen content in water refers to the total amount of dissolved molecular oxygen (O₂) present per unit volume, typically expressed in milligrams per liter (mg/L) or as percent saturation relative to atmospheric equilibrium. It is governed by gas solubility equilibria (primarily Henry’s law), temperature, salinity, and pressure, as well as biological and chemical processes such as photosynthesis, respiration, and oxidation reactions. Oxygen content is a key parameter in aquatic system characterization, influencing redox conditions, biogeochemical cycling, and habitat suitability, and is routinely measured using electrochemical or optical sensors in limnological, oceanographic, and water-quality research.
Some animals can regrow lost body parts. Salamanders and frog tadpoles can rebuild entire limbs after amputation. Mammals cannot. For decades, biologists have tried to understand why. Now a team led by Can Aztekin at EPFL ...
Plants & Animals
6 hours ago
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Scientists have found a new way to detect subtle chemical signatures in seawater, revealing previously invisible details about the ocean's chemistry from data continuously collected by thousands of autonomous robotic floats ...
Earth Sciences
Apr 6, 2026
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Cyanobacteria, as they still exist today, were the first organisms to carry out photosynthesis and release oxygen. Produced in primeval oceans about 2.5 billion years ago, this oxygen accumulated in Earth's atmosphere on ...
Earth Sciences
Feb 26, 2026
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66
Seamounts and the oxygen minimum zone (OMZ) are two typical deep-sea habitats that often coexist. However, determining whether the "seamount effect" alters OMZ structure through marine stratification, thereby influencing ...
Earth Sciences
Feb 5, 2026
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A new study suggests the world's oxygen-depleted seas may have a chance of returning to higher oxygen concentrations in the centuries to come, despite our increasingly warming climate.
Earth Sciences
Jan 29, 2026
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The ocean is continuously ventilated when surface waters sink and transport, for example, oxygen and carbon to greater depths. The efficiency of this process can be estimated using the so-called water age, which describes ...
Earth Sciences
Jan 20, 2026
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1224
A team of scientists announced Tuesday they have developed new deep-sea landers specifically to test their contentious discovery that metallic rocks at the bottom of the ocean are producing "dark oxygen".
Earth Sciences
Jan 20, 2026
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1287
Research reveals when and why ancient tropical seas transitioned from oxygen oases to marine dead zones, providing clues to the long-term evolution of oceanic environments.
Earth Sciences
Jan 16, 2026
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36
For roughly 2 billion years of Earth's early history, the atmosphere contained no oxygen, the essential ingredient required for complex life. Oxygen began building up during the period known as the Great Oxidation Event (GOE), ...
Astrobiology
Dec 9, 2025
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81
Earth's ocean, the planet's life-support system, is experiencing rapid and widespread transformations that extend far below its surface. A promising international study published in Nature Climate Change reveals that vast ...
Earth Sciences
Nov 25, 2025
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