NSF East Asia and Pacific Summer Institute (EAPSI) for FY 2013 in Japan

Case David H, Pasadena CA

Investigators

Abstract

This action funds David Hamilton Case of the California Institute of Technology to conduct a research project in Geosciences during the summer of 2013 at the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) in Kochi, Japan. The project title is "Understanding Which Microbial Species Live Below the Seafloor and What They Eat." The host scientist is Dr. Fumio Inagaki. Marine mud volcanoes are hydrocarbon-rich areas where sediment is moved upward from deep within Earth's oceanic crust to the seafloor. Samples taken from the top of a marine mud volcano (i.e., the seafloor) are often assumed to be representative of geochemical and biological conditions deep within the oceanic crust (i.e., 100s of meters below the seafloor). This study directly tests this assumption by recovering biological samples from the top of a marine mud volcano and 115 meters below the ocean floor. Starting in 2012 biological samples were incubated with stable isotope-labeled food sources (e.g. 13C-methane, 13C-glucose, 15N-ammonium) for one year. Following incubation and with the assistance of EAPSI 2013 support microbiological cells are (1) identified by phylogeny and (2) analyzed for isotopic content to determine which cells consumed which food sources. This informs the identity and metabolic function of microbial communities in Earth's subsurface and tests the assumption that the top and bottom of marine mud volcanoes contain identical conditions. Broader impacts of an EAPSI fellowship include providing the Fellow a first-hand research experience outside the U.S.; an introduction to the science, science policy, and scientific infrastructure of the respective location; and an orientation to the society, culture and language. These activities meet the NSF goal to educate for international collaborations early in the career of its scientists, engineers, and educators, thus ensuring a globally aware U.S. scientific workforce. Furthermore, society will benefit by increased knowledge of the microbial controls on geochemistry in a hydrocarbon-rich environment which has been proposed as a potential untapped source of natural gas. Additionally, the Fellow is involved in teaching K-12 science through activities, lessons, and talks. Sharing stories, photographs, and excitement for science with a young audience promotes teaching, training, learning, and inspiration of future generations of scientists.