During the past two years, scientists have successfully tapped the chemical reactions from decomposing organic matter on the ocean floor to create fuel cells that can provide low levels of electrical power for many months. Recently, Oregon State University (OSU) researchers announced that they have taken that development one step farther by harnessing the same power-producing decomposition activity from plankton taken from the upper water column.
In three seafloor experiments, OSU researchers have tested prototype fuel cells in Newport's Yaquina Bay; in a salt marsh in Tuckerton, NJ, and at chemical seeps in a deep-sea canyon off Monterey, CA. The devices consisted of graphite anodes embedded in marine sediments connected to graphite cathodes in the overlying seawater. Power was generated both by the direct oxidation of dissolved sulfide - which is a byproduct of microbial decomposition - and by the respiration processes of microorganisms that attached themselves to the anode.
"We've only had the experiments running for about four weeks," said Clare Reimers, a professor in the College of Oceanographic and Atmospheric Sciences at OSU, "but it is clear that we can use plankton as a fuel source and that the water column is rich in microorganisms adept at shuttling electrons to fuel cell electrodes. The seafloor fuel cells that we've developed in the past are stationary and designed to provide power for equipment that doesn't move - like the hydrophones used by the US Navy or by OSU researchers for listening for earthquakes."
