A new study in the journal Nature Geosciences describes a discovery that challenges what scientists previously thought about oxygen production in the ocean. 

Sensor data revealed there are polymetallic nodules located 13,000 feet below the ocean’s surface that hold valuable metals used in the manufacture of lithium-ion batteries, among other industrial processes.

These nodules are also capable of producing oxygen, despite being engulfed in complete darkness. This “dark oxygen” provides new insights into the origin of life.

"For aerobic life to begin on the planet, there had to be oxygen and our understanding has been that Earth's oxygen supply began with photosynthetic organisms," said Sweetman, a professor at the Scottish Association for Marine Science and lead of the institution’s seafloor ecology and biogeochemistry group.

"But we now know that there is oxygen produced in the deep sea, where there is no light. I think we therefore need to revisit questions like: where could aerobic life have begun?

"The discovery of oxygen production by a non-photosynthetic process requires us to rethink how the evolution of complex life on the planet might have originated.”

Nicholas Owens, Director of the Scottish Association for Marine Science added, “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 scientists note that the newly discovered nodules may have a much larger impact on the marine ecosystems they reside in, than known prior, making it an important factor to consider when laying out deep-sea mining regulations.