A team led by Professor Andrew Sweetman from the Scottish Association for Marine Science has found evidence of oxygen being generated in the lightless depths of the Pacific Ocean, a phenomenon they’ve dubbed “dark oxygen.” This is a groundbreaking discovery that could revolutionize our understanding of oxygen production on Earth.
The study, published in the journal Nature Geoscience, suggests that electrically charged minerals called polymetallic nodules may be responsible for this unexpected oxygen production. These nodules, ranging from particle-size to potato-size, are believed to split seawater into hydrogen and oxygen through a process known as seawater electrolysis.
“I think we therefore need to revisit questions like: where could aerobic life have begun?” Sweetman stated in a news release.
This “dark oxygen” discovery challenges the long-held belief that oxygen on Earth is produced solely through photosynthesis, a process requiring sunlight. The implications of this finding are far-reaching, potentially affecting theories about the origins of life itself.
Nicholas Owens, director of the Scottish Association for Marine Science, emphasized the significance of the discovery:
“The conventional view is that oxygen was first produced around three billion years ago by ancient microbes called cyanobacteria and there was a gradual development of complex life thereafter. The potential that there was an alternative source requires us to have a radical rethink.”
The research team conducted tests both on the seafloor and with collected samples above ground, consistently observing increased oxygen levels near the polymetallic nodules. Some nodules were found to possess up to 0.95 volts of electricity, with multiple nodules together producing even higher voltages.
While this “dark oxygen” discovery opens up new avenues for scientific exploration, it also raises concerns about deep-sea mining. Polymetallic nodules contain valuable metals such as manganese, nickel, and cobalt, which are crucial for manufacturing lithium-ion batteries used in various electronic devices and electric vehicles.
Franz Geiger, a Northwestern University chemistry professor involved in the study, cautioned about the potential environmental impact of deep-sea mining.
“We need to be really careful if it turns out that deep-sea mining will become an opportunity that’s being pursued … that’s done on a level and at a frequency that is not detrimental to life down there,” Geiger said to NPR.
The researchers noted that previous exploratory mining missions in the 1970s and ’80s might have had long-lasting negative effects on marine life in the affected areas. This rightly underscores the need for careful consideration and further research before any large-scale deep-sea mining operations are undertaken.
