'Dead' Deep Sea Vents Teem with Life

Volcanic seafloor vents that roar with the scalding heat of Earth's interior don't stay hot forever. Eventually, over hundreds or thousands of years, they flicker out and turn cold.

Yet new research reveals that the action on these oases of life on the seafloor doesn't stop when the heat goes off. Life goes on in the frigid dark, but on a teeny scale.

It turns out that large populations of bacteria live on expired vents, and these microbes are very different from those that thrive when the vents are piping hot, according to a study published this week in the journal mBio.

Scientists found evidence that up to 2,000 different sorts of microbes were living in a small section of a long-expired vent near the East Pacific Rise, a vast seam on the seafloor in the southern Pacific Ocean where two tectonic plates are being wrenched apart. For comparison, up to 8,000 varieties of microbes have been found living on active, hot vents, and up to 10,000 in deep seawater.

Although finding the microbes themselves didn't come as a huge shock — scientists have found bacteria living in other types of cool seafloor rocks — the revelation of who exactly moved in once the vents went cold was surprising, according to the study authors.

"Seeing the shift in the microbial population — seeing who actually came and left was fairly illuminating for me," said study co-author and geomicrobiologist Katrina Edwards, a professor at the University of Southern California.
Source:Yahoo