This project supports the 4th international symposia on Chemosynthetically-based ecosystems to be held in Okinawa Japan June 29 to July 3rd, 2009. This symposia focuses on the novel metabolism and adaptations of macro- and micro-organisms to environments with elevated concentrations of reduced chemicals. The energy harnessed during the biological oxidation of these chemicals (eg., S, CH4) is ultimately stored as cellular organic carbon during CO2 fixation by prokaryotic bacteria, which may occur as free living forms or as symbionts of macrofauna. The symposia is being coordinated by an international team of scientists, including members of the organizational committee from the Scripps Institution of Oceanography and the University of Hawaii. The symposia will be attended by researchers from numerous US institutions with diverse fields of discipline including geochemistry, microbiology, molecular biology, ecology and biogeography.