Produced by: Tarun Mishra Designed by: Manoj Kumar
Researchers have discovered that metallic minerals on Earth's deep-ocean floor are causing chemical reactions that produce "dark oxygen," a phenomenon previously unknown to science.
The findings, published in Nature Geoscience, reveal that oxygen is being generated in the absence of life, challenging the belief that only photosynthetic organisms produce oxygen.
The study, titled "Evidence of dark oxygen production at the abysmal seafloor," suggests oxygen can be created at the seafloor, where light does not reach, supporting aerobic marine life in total darkness.
Andrew Sweetman from the Scottish Association for Marine Science (SAMS) made the discovery during fieldwork in the Pacific Ocean, with electrochemistry experiments led by Northwestern's Franz Geiger providing potential explanations.
The phenomenon was first noticed in 2013 during studies of sea-floor ecosystems in the Clarion–Clipperton Zone. Persistent sensor readings indicated unexpected oxygen production.
Sweetman highlighted the need to reconsider the origins of aerobic life, noting that this discovery suggests oxygen can be produced in the deep sea without photosynthesis.
Black and rounded polymetallic nodules on the ocean floor are key to this discovery. These mineral deposits, containing metals like cobalt, nickel, copper, lithium, and manganese, are critical for oxygen production.
Geiger emphasized the importance of rethinking deep-sea mining practices to avoid depleting oxygen sources for deep-sea life, as large-scale mining companies aim to extract valuable elements from these nodules.
Researchers found that oxygen levels are slowly increasing at depths over 4,000 meters, suggesting ongoing chemical reactions. This discovery opens new avenues for understanding deep-sea ecosystems and the origins of life on Earth.