Third of Earth's organisms live in rocks, sediments

London, Aug 8 (IANS) A third of the Earth's organisms live in our planet's rocks and sediments - and the amount could even be greater undersea than what we find on the surface, scientists say.

Microbiologist James Holden of the University of Massachusetts-Amherst and his colleagues revealed the first detailed data on methane-exhaling microbes that live deep in the rocks and sediments, the Daily Mail reported Wednesdasy.

Just as biologists studied the habitats and life requirements of giraffes and penguins when they were new to science, Holden says, "for the first time we're studying these subsurface micro-organisms, defining their habitat requirements and determining how they differ among species".

"Evidence has built that there's an incredible amount of biomass in the Earth's subsurface, in the crust and marine sediments, perhaps as much as all the plants and animals on the surface," said Holden.

"We're interested in the microbes in the deep rock, and the best place to study them is at hydrothermal vents at undersea volcanoes. Warm water there brings the nutrient and energy sources these microbes need," the Mail quoted him as saying.