A recent international study has uncovered that deep-sea minerals can produce oxygen in complete darkness, suggesting an oxygen source that predates photosynthetic life. This finding could significantly impact deep-sea mining, highlighting the need for sustainable practices to protect these crucial oxygen sources.
Oxygen Generation in the Abyss
An international research team, including a chemist from Northwestern University, discovered that metallic minerals on the ocean floor generate oxygen at depths of 13,000 feet. This surprising discovery challenges the long-held belief that only photosynthetic organisms, such as plants and algae, produce Earth’s oxygen. The study, published in Nature Geoscience, reveals that oxygen can also be produced in the deep sea, where no light reaches, enabling aerobic marine life to exist in total darkness.
Andrew Sweetman from the Scottish Association for Marine Science (SAMS) found this “dark oxygen” during fieldwork in the Pacific Ocean. Franz Geiger from Northwestern led the electrochemistry experiments explaining this phenomenon. Sweetman stated, “For aerobic life to emerge, there had to be oxygen, and we thought photosynthetic organisms were the primary source. But now we know oxygen is produced in the deep sea, where light is absent.”
Polymetallic Nodules and Mining Implications
Polymetallic nodules, natural mineral deposits on the ocean floor, are central to this discovery. These nodules contain metals like cobalt, nickel, copper, lithium, and manganese, essential for battery production. “Several large-scale mining companies aim to extract these elements,” said Geiger. “We must rethink how to mine these materials without depleting the oxygen source vital for deep-sea life.”
Hidden “Geobatteries”
The team found that polymetallic nodules might generate enough electricity to produce oxygen through seawater electrolysis. Geiger noted, “It appears we have discovered a natural ‘geobattery’.”
Researchers emphasize that the mining industry must consider this discovery before proceeding with deep-sea mining to avoid disrupting these newly identified oxygen-producing systems and to adopt more sustainable and cautious approaches.
