As the deep ocean faces growing peril from climate change, seabed mining and other threats, scientists have discovered that seafloor sediments are home to vast populations of previously unknown organisms that may play a crucial role in carbon sequestration and marine food webs.

When researchers analyzed DNA sequences taken from sediment samples from around the world, they were astonished to find that nearly two-thirds were new to science, representing entire families of undescribed life forms, according to a study published Feb. 4 in the journal Science Advances.

"It highlights a very large knowledge gap for the ocean,” said Tristan Cordier, lead author of the study and a senior researcher at NORCE, an independent Norwegian research institute. "We don’t know at all what these bugs are doing, and their role in carbon storage, the carbon cycle and biochemical cycles are largely unknown.”