SAMS Leads Groundbreaking Discovery of ‘Dark Oxygen’ in Pacific Ocean, Challenging Life Origins Theory

(IN BRIEF) A study led by the Scottish Association for Marine Science (SAMS) has discovered that oxygen can be produced in complete darkness at the seafloor, challenging the traditional understanding that oxygen production is solely through photosynthesis. This finding, published in Nature Geoscience, was made during research in the Pacific Ocean’s Clarion-Clipperton Zone. The study found that high electric charges in polymetallic nodules can cause seawater electrolysis, producing oxygen. This revelation prompts a reassessment of how deep-sea mining impacts the environment and the origins of aerobic life on Earth.

(PRESS RELEASE) OBAN, 23-Jul-2024 — /EuropaWire/ — A revolutionary discovery in the depths of the Pacific Ocean is prompting scientists to reconsider the established understanding of how oxygen is produced and the origins of life on Earth. Published today in Nature Geoscience, new evidence reveals that oxygen can be produced in complete darkness at the seafloor, 4,000 meters below the ocean surface, far beyond the reach of sunlight.

This discovery was made by a team led by Prof. Andrew Sweetman of the Scottish Association for Marine Science (SAMS) in Oban, a partner of UHI, during fieldwork in the Pacific Ocean. The research aimed to assess the potential impacts of deep-sea mining in the Clarion-Clipperton Zone, a region rich in polymetallic nodules essential for manufacturing lithium-ion batteries.

Prof. Sweetman explained, “Our understanding has been that Earth’s oxygen supply began with photosynthetic organisms. However, we now know that oxygen is produced in the deep sea, where no light penetrates. This raises fundamental questions about the origins of aerobic life on Earth.”

The team discovered that these polymetallic nodules carry a high electric charge, leading to the electrolysis of seawater into hydrogen and oxygen. They recorded voltages up to 0.95 volts on the nodules’ surfaces, sufficient to trigger seawater electrolysis. This process typically requires a voltage of only 1.5 V, the same as a standard AA battery.

Initially skeptical of their findings, the team validated the results with alternative methods, confirming the presence of “dark oxygen” production. This discovery necessitates further investigation, particularly concerning the implications for deep-sea mining and how sediment disruption during mining might affect this oxygen production process.

Prof. Sweetman emphasized the need for caution in deep-sea mining operations, stating, “We have generated many unanswered questions about how we mine these nodules, which function like batteries in a rock. This discovery calls for a thorough reassessment of mining impacts on deep-sea environments.”

SAMS Director Prof. Nicholas Owens hailed the findings as one of the most exciting developments in ocean science, suggesting that the discovery of non-photosynthetic oxygen production might alter our understanding of the evolution of complex life on Earth. “The conventional view is that oxygen was first produced around three billion years ago by ancient microbes called cyanobacteria. The potential for an alternative oxygen source requires a radical rethink,” he said.

This groundbreaking discovery underscores the importance of continued exploration and study of our planet’s deep-sea environments, with profound implications for both science and industry.

About us

The Scottish Association for Marine Science (SAMS) has been delivering independent marine science since 1884. Based in Oban, 150 staff are working for healthy and sustainably managed seas and oceans through world-class marine research, education and engagement with society.

Media Contact:

Euan Paterson
Communications and Media Officer
Euan.Paterson@sams.ac.uk
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SOURCE: Scottish Association for Marine Science

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