'Dark' oxygen that is not made by plants discovered at the bottom of the ocean

'Dark' oxygen that is not made by plants discovered at the bottom of the ocean. Scientists have discovered a large amount of oxygen at the bottom of the Pacific Ocean. This is not made by plants, but by stones that contain certain metals. The scientists call it 'dark oxygen'.

It has long been assumed that the oxygen that humans breathe is only produced naturally through photosynthesis. During this process, living things convert carbon dioxide into oxygen under the influence of sunlight. Trees, algae in the ocean and even some bacteria are capable of this.

But sunlight does not reach the bottom of the Pacific Ocean, about 5 kilometers deep. The oxygen that the scientists found there was made by round, black stones. They work like a kind of natural batteries, the researchers write in Nature Geoscience.

The so-called 'geobatteries' are stones consisting of metals such as cobalt, manganese and nickel. This composition ensures that the stones react with each other and generate electric current among themselves.

"The electric charge splits the seawater into the elements oxygen and hydrogen," say Franz Geiger and research leader Andrew Sweetman. "If you put one battery in a flashlight, it won't work. But if you put two, you have enough power. It's the same thing with these rocks on the ocean floor."

Researchers fear that stones will be fished out

Sweetman said he made the discovery before, but then ignored it. "In 2013, I discovered a large amount of oxygen in the complete darkness of the seabed. At the time, I thought it was a mistake, because I had always learned that oxygen is only made by photosynthesis."

Because this way of producing oxygen is completely different from what was previously assumed, the researchers call it 'dark oxygen'. Sweetman's fellow marine biologist Nicholas Owens calls the discovery "one of the most exciting discoveries in the recent history of ocean science."

According to Sweetman and Geiger, the discovery raises new questions about the origin of life. The researchers now want to investigate the process further. However, they are afraid that companies want to fish for the stones and thus disrupt the ecosystem in the Pacific Ocean.

Reference(s).. www.nature.com & other media