The world's oceans contain many more types of microorganisms than had been thought, scientists report.
The study, reported in Monday's online edition of Proceedings of the National Academy of Sciences, found more than 20,000 species in a liter of seawater. "Microbiologists have formally described 5,000 microbial species. This study shows we have barely scratched the surface," said Mitchell Sogin of the Marine Biological Laboratory at Woods Hole, Mass.
