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‘Dark oxygen’ discovery on the Pacific Ocean floor stuns scientists and could rewrite origins of life

Scientists have made a stunning discovery on the ocean floor, 4000 metres below the surface, that could upend our understanding of the origin of life.

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The secret to life on Earth could be deeper than we thought.

Scientists have discovered that metal nodules on the ocean floor are producing oxygen in total darkness without any aid from living organisms, which could upend our understanding of the origin of life.

This eye-opening revelation was revealed in a groundbreaking study in the journal Nature Geoscience.

“I think we need to revisit questions like where could aerobic life (life that requires oxygen) have begun?” the study’s lead author Andrew Sweetman, professor of sea floor ecology at the Scottish Association for Marine Science (SAMS) in Oban, UK, said in a statement.

A carnivorous sponge, Axoniderma mexicana. Picture: National Oceanography Centre/SMARTEX Project
A carnivorous sponge, Axoniderma mexicana. Picture: National Oceanography Centre/SMARTEX Project

Prof Sweetman and his team discovered the phenomenon, dubbed “dark oxygen”, accidentally while sampling the seabed over 3960 metres down in a 1.7 million square mile swath of sea floor located between Mexico in Hawaii.

They had originally set out to assess the impacts of mining the aforementioned metal nuggets, including cobalt, nickel and rare earth metals such as cerium (an essential component of certain electronics).

However, while scanning the seabed, the sensors detected mysterious oxygen emissions originating in the area.

This phenomenon seemed impossible given that the area was too deep for light to penetrate and therefore foster photosynthesis, the process by which plants and other organisms convert water and carbon dioxide into oxygen and energy.

A glass sponge from the Euplectellidae family. Picture: National Oceanography Centre/SMARTEX Project
A glass sponge from the Euplectellidae family. Picture: National Oceanography Centre/SMARTEX Project

However, this discovery marked the first time that scientists had observed oxygen being generated without the involvement of organisms.

Prof Sweetman was so flabbergasted by the finding that he “initially thought the sensors were faulty”.

“Every study ever done in the deep sea has only seen oxygen being consumed rather than produced,” said the shocked scientist, who sent the equipment back to the manufacturer for testing, only to have them confirm that it was working fine.

Prof Sweetman determined through subsequent experiments that the metallic nodules create this “dark oxygen” through a process called seawater electrolysis.

This occurs when seawater divides into oxygen and hydrogen while in the proximity of an electric charge, which in this case, is provided by the highly-charged metal ovals like an aquatic battery.

The polymetallic nodules are producing oxygen. Picture: Camille Bridgewater/Northwestern University
The polymetallic nodules are producing oxygen. Picture: Camille Bridgewater/Northwestern University

“Only a voltage of 1.5V is needed for seawater electrolysis to occur -- the same voltage as a typical AA battery,” the authors wrote in the statement.

“The team analysed multiple nodules and recorded readings of up to 0.95 volts on the surfaces of some, meaning that significant voltages can occur when the nodules are clustered together.”

In other words, nature is so metal.

Ultimately, Prof Sweetman believes that discovery could challenge our perception of how life on Earth began approximately 3.7 billion years ago.

“For aerobic life to begin on the planet, there has to be oxygen and our understanding has been that Earth’s oxygen supply began with photosynthetic organisms,” he said. “But we now know that there is oxygen produced in the deep sea, where there is no light.”

This revelation also sparks concerns about the potential environmental ramifications of harvesting the metallic lumps, which could provide a crucial source of oxygen for these deep-sea habitats.

This article originally appeared on NY Post and was reproduced with permission

Originally published as ‘Dark oxygen’ discovery on the Pacific Ocean floor stuns scientists and could rewrite origins of life

Original URL: https://www.themercury.com.au/technology/environment/dark-oxygen-discovery-on-the-pacific-ocean-floor-stuns-scientists-and-could-rewrite-origins-of-life/news-story/58855f227ba1bdc32097962bfc798176