Discovery of ‘Dark Oxygen’ in the Deep Sea Challenges Scientific Beliefs

A team of researchers has made a surprising discovery deep beneath the Pacific Ocean: potato-sized metallic nodules are producing oxygen all on their own, even in total darkness and without any help from living organisms.

This phenomenon, dubbed ‘dark oxygen’, is revolutionary because scientists have always believed oxygen could only come from living things, like plants that photosynthesize. The team, led by Andrew Sweetman from the Scottish Association for Marine Science, was initially stunned. When their sensors started detecting oxygen production, they thought there might be a mistake.

But the data kept rolling in, showing steady oxygen emissions from the seafloor in the Clarion-Clipperton Zone. This area is about 13,000 feet under the ocean’s surface, where no light penetrates and typical oxygen levels are expected to drop.

What they found was that these metallic nodules, rich in oxides of iron and manganese, might be generating a small electric charge that causes seawater to split into oxygen and hydrogen—a process called electrolysis. This charge could stem from the metal ions in the nodules, shifting electrons around and kickstarting the production of oxygen.

Sweetman and his team were actually studying the environmental impacts of mining these precious nodules for their metals like lithium and cobalt when they stumbled upon this unknown process. The implications of this finding raise questions about how life might have started on Earth and whether similar processes could occur on other planets.

While this breakthrough opens a window into the past, it also raises concerns for the future. If deep-sea mining disrupts these oxygen-producing nodules, it could jeopardize a critical oxygen source for deep-sea ecosystems, reminding us of the delicate balance present in the ocean floor.