‘Dark Oxygen’ Found in Deep Sea Metal Lumps Sparks Reevaluation of Life’s Origins
‘Dark Oxygen’ Found in Deep Sea Metal Lumps Sparks Reevaluation of Life’s Origins Scientists working in the Clarion-Clipperton Zone in the North Pacific Ocean have made a groundbreaking discovery: potato-sized metallic nodules on the seafloor produce oxygen independently, even in complete darkness. This phenomenon, termed “dark oxygen,” challenges existing understandings of oxygen production and the origins of life on Earth.
Lead author Andrew Sweetman, from the Scottish Association for Marine Science (SAMS), described initial disbelief when their instruments consistently detected oxygen production rather than consumption in the deep-sea environment. Published in Nature Geoscience, their study suggests that polymetallic nodules in the Clarion-Clipperton Zone generate oxygen through seawater electrolysis, facilitated by the electric potential among metal ions within the nodules.
Polymetallic nodules, containing iron and manganese oxides alongside metals like cobalt and nickel, are prevalent in the abyssal plains of the ocean floor, spanning depths of 10,000 to 20,000 feet. Originally investigating the environmental impacts of mining these nodules, the team found unexpected oxygen emissions using experimental chambers at various locations.
This discovery challenges the notion that oxygen is exclusively produced through photosynthesis or ammonia oxidation, especially in light-deprived regions of the ocean. Sweetman highlighted implications for understanding the origins of aerobic life on Earth, suggesting a need to reconsider where and how oxygen production may have initiated.
Moreover, the findings raise ethical and ecological concerns about potentially mining these nodules, which could serve as crucial oxygen sources for deep-sea ecosystems. Sweetman emphasized the need for further research to address the new questions and implications stemming from this discovery.
