According to findings that could have been pulled from a deep-sea sequel to Avatar, bacteria appear to conduct electrical currents across the ocean floor, driving linked chemical reactions at relatively vast distances.

Noticed only when reseachers happened to test sediment leftovers from another experiment, the phenomenon may add a new mechanism to Earth’s biogeochemistry.

“The cycling of elements and life at the bottom of the sea, and in soil, and anywhere else you’re short of oxygen — this could help us understand those processes,” said microbiologist Lars Peter Nielsen of Denmark’s Aarhus University, co-author of the study, published Feb. 24 in Nature.

The original focus of Nielsen’s team wasn’t seafloor conductivity, but an especially interesting species of sulfur bacteria found on the floor of Aarhus Bay. To help quantify their chemical activity, the researchers kept a few beakers of seawater and sulfur bacteria-free sediment for comparison.

After those experiments ended, the beakers were almost forgotten. Then, a few weeks later, the researchers noticed strange patterns of activity. Changing oxygen levels in water above the top sediment layer were almost immediately followed by chemical fluctuations several layers down. The distance was so great, and the response time so quick, that usual methods of chemical transport — molecular diffusion, or a slow drift from high to low concentration — couldn’t explain it.

http://www.wired.com/2010/02/electric-ocean-bacteria/