Bo Parker Jorgensen, a marine biochemist who was not involved in the research but peer-reviewed the study, said in an interview that it was a “very unusual finding.”
The findings could have implications for the deep-sea mining industry, which should allow players to explore the depths of the ocean and recover minerals that form polymetallic nodules. Such minerals Considered critical to the green energy transition. Environmentalists and others Scientists believe Deep sea mining is dangerous Because it can disrupt ecosystems in unpredictable ways and affect the ocean’s ability to help control climate change. The study received funding from organizations involved in seabed mining research.
When Andrew Sweetman, lead author of the study, first recorded unusual oxygen measurements from the bottom of the Pacific Ocean in 2013, he thought his research equipment was malfunctioning.
“I basically told my students, put the sensors back in the box. We send them back to the manufacturer and they get tested because they look stupid to us,” said Sweetman, chair of the Coastal Ecology and Biochemistry Research Group at the Scottish Association for Marine Science. told CNN. “Every time the manufacturer comes back: ‘They work. They’re calibrated.
In 2021 and 2022, Sweetman and his team returned to the Clarion-Clipperton zone, which is known to contain the largest number of polymetallic nodules in the central Pacific. Hoping the sensors would work, they lowered the device, which places small boxes into the sediment, more than 13,000 feet. The boxes remained there for 47 hours, conducting experiments and measuring the amount of oxygen consumed by the microbes living there.
Instead of oxygen levels going down, they went up—suggesting that more oxygen was being produced than was being consumed.
Researchers hypothesize that it is the electrochemical activity of different metals that form polymetallic nodules. Those responsible for oxygen production—measured by sensors—like a battery where electrons flow from one electrode to another, create a current, Tobias Hahn, one of the study’s co-authors, said in an interview.
This hypothesis would add a layer to our understanding of how life evolved under the sea, said Hahn, who focused specifically on the sensors used in the probe experiments. “Because oxygen was brought to Earth through photosynthesis, we thought life on Earth began when photosynthesis began. In fact, this electrochemical process of splitting water into oxygen and hydrogen supplied oxygen to the ocean,” he said.
“This could be a kind of game changer in the story of how life began,” he added.
A Press release on the study Its findings “challenge long-held assumptions that only photosynthetic organisms such as plants and algae produce Earth’s oxygen.”
But if the discovery is confirmed, Franz Geiger said, “we have to rethink how we mine cobalt, nickel, copper, lithium and manganese” underwater, “so that we don’t deplete the oxygen source for life in the deep sea.” , professor of chemistry at Northwestern University and one of the study’s co-authors, in the publication.
Undersea mining in the 1980s serves as a cautionary tale, Geiger said. When marine biologists visited such sites decades later, they “found that not even the bacteria were recovered.” But in the unmined areas, “sea life thrived.”
“Why such ‘dead zones’ persist for decades is still unknown,” he said. But the reality they do is that seabed mining in areas with abundant polymetallic nodules is particularly harmful, he said, because those areas have more faunal diversity than “highly diverse tropical rainforests.”
Although the study points to an interesting new path to sustaining life under the sea, many questions remain, Hahn said. We don’t know how much “dark oxygen” can be produced by this process, how it affects the polymetallic nodules, or how many nodules are needed to activate oxygen production, he said.
While the research methodology is solid, “there’s a lack of understanding of what’s going on and what kind of process it is,” Parker Jorgensen said.
