More Life Than We Ever Realized Could Survive in The Deep Dark of The Ocean - ScienceAlert

Instead of using photosynthesis to store energy in their chemical bonds, some microbes rely purely on the oxidation of inorganic molecules like hydrogen to do the trick.

Chemosynthesis, as it's known, was speculated as a potential source of energy for microbes in the 19th century, though wasn't confirmed until ecosystems surrounding deep ocean hydrothermal vents were discovered in the 1970s.

In fact, as sunlight fades to darkness, a team led by researchers from Monash University in Australia has found evidence that chemosynthesis becomes the primary way of life for invisible marine microbes.

"Hydrogen and carbon monoxide in fact 'fed' microbes in all regions we've looked at: from urban bays to around tropical islands to hundreds of meters below the surface," says Monash University microbiologist Chris Greening.

Unlike sunlight, molecular hydrogen is a convenient source of energy that is present in at least trace amounts across a wide variety of ecosystems, from the atmosphere to the surface and even below.

In previousstudies, Greening and his colleagues have shown that in a lot of the world's soil, bacterial cultures that can consume hydrogen are "abundant, diverse and active" – in many ways, the base of the entire food chain.