Scientists Discover 'Dark Oxygen' on the Seafloor, Challenging Long-Held Theories
Scientists have discovered "dark oxygen" in the deep sea, challenging the belief that oxygen is only produced through photosynthesis. This breakthrough, published in Nature Geoscience, has implications for marine ecosystems, deep-sea mining, and even the search for extraterrestrial life.
There has been a recent scientific discovery that identified an unknown source of oxygen generation in the deep ocean, contrary to the long-prevailing concept that oxygen is formed solely through photosynthesis. Scientists found traces of "dark oxygen," a process through which oxygen is produced without sunlight, at 4,000 meters within the Clarion-Clipperton region of the Pacific Ocean. This find, published in Nature Geoscience in 2024, can revolutionize our understanding of ocean ecosystems and planetary science as well as raise issues about deep-sea mining.
The find was made in 2013 when researchers were working on seafloor carbon cycling using a remote-operated lander system. The equipment measured oxygen production at record-breaking depths, a remarkable finding at first blamed on a sensor fault. But a second method used in 2021 demonstrated that oxygen was actually being produced in the dark deep ocean with no sunlight. Scientists believe that polymetallic nodules—mineral structures similar to rocks, which are rich in manganese, nickel, and cobalt—could be responsible. These nodules could be reacting with seawater to create an electrical charge strong enough to split water molecules and release oxygen. Supporting this hypothesis, one recent Chinese study concluded that oxygen can be generated during natural manganese nodule formation.
The consequences of dark oxygen formation reach beyond Earth's oceans. NASA is currently exploring its possibility of sustaining life on other planets, particularly on ocean-surrounded moons like Europa and Enceladus. These planets have dense ice layers that block sunlight, but if oxygen can be made in the dark on Earth, the same thing would take place elsewhere in the universe.
Researchers are currently conducting their studies deeper, using advanced autonomous landers with high-accuracy instruments to study seafloor activity as deep as 11,000 meters. The studies aim to determine if hydrogen is also released during dark oxygen production and if deep-sea microorganisms utilize it as an energy source. Another focal point of investigation is the degree to which climate change can influence these processes and sea life.
Apart from scientific research, dark oxygen production has significant implications in the deep-sea mining economy. Polymetallic nodules, responsible for oxygen production, are of significant interest since they contain valuable metals used in lithium-ion batteries in electric vehicles and electronics. However, extensive mining activities may disrupt oxygen production and influence marine ecosystems in unknown ways. The scientists would like to quantify these risks and provide some insight into how mining activities might affect ocean ecosystems.
The discovery of dark oxygen is a major ocean science breakthrough and raises new questions regarding the deep-sea habitats on our planet and the possibility of life elsewhere in the universe. The future will determine how dark oxygen functions ecologically and the possible effects that human mining operations might have. As research goes on, scientists look to gain further insight into the workings of the deep ocean and gain its protection.
Source & Credits:
Original Research in Nature Geoscience (2024)
Article Adapted from The Conversation by Andrew Sweetman
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