The deep seas seem to produce their own oxygen.

About the episode

Trees produce oxygen, algae do, but now researchers say they’ve discovered a new source of oxygen, in the form of heavy metals.

It was thought that only organisms using photosynthesis could produce oxygen. But these metal balls can be found at a depth of about 4,000 meters, at the bottom of the ocean, in complete darkness.

The researchers who discovered this initially thought their measuring equipment was broken. But after years of measurements and experiments in the lab, they now think they know for sure.

Metals, especially when they clump together, produce electricity. Enough to start a chemical reaction that can produce oxygen. That means we may have to think differently about the origins of life.

Organisms that need oxygen to survive, including many animal species, probably did not arise through photosynthesis alone. The minerals now being studied may have provided sufficient oxygen.

They are composite fragments containing a mixture of metals such as copper, nickel, cobalt and lithium. Their size ranges from a grain of sand to a potato.

And yes: these are indeed the raw materials we use to make our batteries. And these tubers are actually being extracted from the seabed through deep-sea mining.

So we must ask ourselves not only what this kind of mining is doing to the soil and marine life itself, scientists say, but also to the oxygen cycle.

Read more about the research here: The deep ocean floor produces its own oxygen.