Third of Earth's creatures in rock & sediments

Sometimes I wonder why we're so interested in life on other planets.... there's a lot more life on OUR planet than we ever thought possible!!  Marine sediments, for example, comprise a whole new world.... teeming with unknown organisms.

The research submarine Alvin reaches with its mechanical arm to a high-temperature black smoker at the Endeavour Segment, Juan de Fuca Ridge, to study methanogenic microbes. (Credit: Bruce Strickrott of WHOI)

Microbiologist James Holden at the University of Massachusetts Amherst, writes: "Evidence has built over the past 20 years that there's an incredible amount of biomass in Earth's subsurface, in the crust and marine sediments, perhaps as much as all the plants and animals on the surface. 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 flows bring the nutrient and energy sources they need."

See the complete article:
Limits of microbial life in an undersea volcano: Third of Earth's organisms live in rock and sediments