One of the largest ecosystems on Earth lives beneath the seafloor and eats radiation byproducts That's pretty metal! Researchers at the University of Rhode Island’s (URI) Graduate School of Oceanography report that a whole ecosystem of microbes below the sea dines not on sunlight, but on chemicals produced by the natural irradiation of water molecules. Image credits Ely Penner. Whole bacterial communities living beneath the sea floor rely on a very curious food source: hydrogen released by irradiated water. This process takes place due to water molecules being exposed to natural radiation, and feeds microbes living just a few meters below the bottom of the open ocean. Far from being a niche feeding strategy, however, the team notes that this radiation-fueled feeding supports one of our planet’s largest ecosystems by volume.