Discovery of liquid CO2 lake in the southern Okinawa Trough hydrothermal field
Microbial life in a sediment-hosted CO2 lake

   Dr. Fumio Inagaki, Sub-leader of Subground Animalcule Retrieval (SUGAR) Program, Extremobiosphere Research Center (Director General; Koki Horikoshi), Japan Agency for Marine-Earth Science and Technology (JAMSTEC: President; Yasuhiro Kato) and his colleagues in collaboration with Hokkaido University, Kyushu University, Okayama University, National Institute of Advanced Industrial Science and Technology (AIST) and Max Planck Institute for Marine Microbiology, have investigated the Yonaguni Knoll IV hydrothermal field in the southern Okinawa Trough by using a manned research submersible "Shinkai 6500". Scientists observed a natural lake of liquid CO2 in sediments on the seafloor near the active hydrothermal vent. Microbiological and biogeochemical analyses revealed that microbial community that assimilates one-carbon compounds such as CO2 and methane inhabits sediments of the CO2 lake. The findings greatly expand our knowledge of life in extreme environments and also contribute to the arguments of CO2 disposal into the deep sea and of extraterrestrial life on other planets.
    The results will be published in Proceedings of the National Academy of Sciences of U.S.A.(PNAS), online issue of the week of August 28, 2006.