Unveiling the Mystery of "Dark Oxygen" in the Deep Ocean
Scientists uncover "dark oxygen" production in deep ocean. Metallic nodules on seabed identified as key players in oxygen generation. Concerns raised over potential disruptions from deep-sea mining activities.
Contrary to previous knowledge, which attributed oxygen production to marine plants through photosynthesis powered by sunlight, this revelation challenges existing scientific understanding.
At a staggering depth of 5km, where sunlight cannot reach, the emergence of oxygen is now believed to stem from naturally occurring metallic nodules that catalyse the splitting of seawater into hydrogen and oxygen. This unexpected process has caught the attention of several mining companies eyeing these nodules, raising concerns among marine experts about potential disruptions to this newfound oxygen-producing mechanism and its impact on marine ecosystems.
Lead researcher Prof Andrew Sweetman from the Scottish Association for Marine Science recounts his initial disbelief upon witnessing substantial oxygen production in complete darkness back in 2013. His realization of this significant discovery, overlooked for years due to preconceived notions, underscores the transformative nature of this finding.
The research conducted by Prof Sweetman and his team in the deep sea region between Hawaii and Mexico revealed a vast expanse of seafloor adorned with these metal nodules. These nodules, formed over millions of years as dissolved metals in seawater accumulate on shell fragments, contain valuable metals like lithium, cobalt, and copper, attracting interest from mining companies aiming to harness them for battery production.
Published in the journal Nature Geoscience, the study sheds light on the nodules' ability to act as natural batteries, generating oxygen akin to an electrolysis process when in contact with seawater. This battery-like mechanism, demonstrated by experiments measuring electric currents comparable to standard AA-sized batteries, unveils a novel pathway for oxygen production in the absence of light or biological processes.
The implications of this discovery extend beyond Earth, with the researchers speculating that similar oxygen-generating processes could be unfolding on other celestial bodies, fostering environments conducive to life. However, the burgeoning interest in deep-sea mining, particularly in the Clarion-Clipperton Zone where the discovery was made, has sparked concerns among environmentalists and marine scientists.
The US National Oceanic and Atmospheric Administration (NOAA) has cautioned against the potential ecological ramifications of seabed mining, prompting over 800 marine scientists from across the globe to advocate for a moratorium on mining activities. Prof Murray Roberts from the University of Edinburgh warns of the irreversible damage that strip mining of deep-sea nodules could inflict on poorly understood ecosystems.
While acknowledging the importance of further exploration, Prof Sweetman emphasises the need for responsible mining practices to safeguard marine habitats. As the scientific community grapples with the implications of this groundbreaking discovery, the delicate balance between technological advancement and environmental preservation hangs in the balance.
Scientists uncover "dark oxygen" production in deep ocean
Metallic nodules on seabed identified as key players in oxygen generation
Concerns raised over potential disruptions from deep-sea mining activities
Source: BBC