DEEP SEA PRODUCE ITS OWN "DARK OXYGEN"
Small metallic nodules, like potato-size strewn across the deep sea ocean seafloor produce oxygen in complete darkness and without any help from living organisms, a new research reveals.
Called polymetallic nodules, are found in the deep sea and produce oxygen through seawater electrolysis, where seawater splits into oxygen and hydrogen in the presence of an electric charge. This charge may come from the difference in electric potential that exists between metal ions within the nodules, which leads to a redistribution of electrons. This is called by scientists as dark oxygen, as is produced without sunlight, as photosintesys does.
-Polymetallic nodules coat fields of the ocean floor Photo: NOAA Office of Ocean Exploration and Research
These nodules polymetallic nodules are common between 3,000 to 6,000 m below the ocean surface. These nodules mostly contain oxides of iron and manganese , but also metals like cobalt, nickel and lithium, as well as rare earth elements such as cerium that are essential components of electronics and low-carbon technologies. This also raise new concerns about potentially mining polymetallic nodules, which could represent a vital source of oxygen for deep-sea ecosystems.
Main photo by Fisheries and Oceans Canada
Reference (Open Access): Sweetman et al., 2024. Evidence of dark oxygen production at the abyssal seafloor. Nat. Geosci.
