New Species Discovered Two Miles Below the Surface of the Ocean

Two miles below the surface of the ocean, a strange species of microbes thrives. Now, scientists have learned a bit more about these new microbes that "breathe" sulfate.

The microbes have yet to be classified and named, but they exist in massive undersea aquifers, which are networks of channels in porous rock beneath the ocean where water continually churns. In fact, about one-third of the Earth's biomass is thought to exist in this largely uncharted environment.

"It was surprising to find new bugs, but when we go to warmer, relatively old and isolated fluids, we find a unique microbial community," said Alberto Robador, one of the researchers, in a news release.

Microbes that breathe sulfate are thought to be some of the oldest types of organisms on Earth. Other species of sulfate-breathing microbes can be found in marshes and hydrothermal vents. Microbes beneath the ocean's crust, though, are difficult to sample.

In order to take these samples, the researchers targeted a region where previous teams had placed underwater laboratories and drilled into the ocean floor. The observatories created a seal at the seafloor, like a cork in a bottle, which allowed scientists to deploy instruments and sampling devices down the borehole while keeping ocean water out. These samples were then shuttled to the surface by remote-controlled undersea vehicles.

"This is the first direct account of microbial activity in these type of environments," said Robador. "And shows the potential of these organisms to respire organic carbon."

The findings reveal a bit more about these strange microbes. This, in turn, could tell researchers a bit more about what life was like on ancient Earth.

The findings are published in the journal Frontiers in Microbiology.