No abstract

No abstract

Over the past decade, the deep subseafloor biosphere has been explored systematically through scientific ocean drilling, revealing that numerous microbial cells are present in dark and old sediments down to over 1,000 meters below sea oor. The subsea oor microbial ecosystem plays signi cant ecological roles in biogeochemical carbon cycle, including degradation of organic matter to methane and formation of hydrocarbon reservoirs. The nature of subseafloor microbial ecosystem provides us some clues to address significant societal issues; e.g., to reduce CO 2 emissions and increase energy efficiency. To discuss the present status and further study potential of these research elds, "The symposium for subsea oor hydrocarbon resources and carbon cycle: Geobiotechnology for sustainable earth and societal systems" was held on January 24 th , 2014 in Koshiba Hall, the University of Tokyo. In this public symposium, the recent studies of subsea oor life and carbon cycle were reviewed, and then possible engineering and/or technological applications of bio-renewable CO 2 and other useful functioning were discussed for developing sustainable carbon and energy circulation systems in the future.