Japan Geoscience Union Meeting 2015

Presentation information

Print

Oral

Symbol M (Multidisciplinary and Interdisciplinary) » M-IS Intersection

[M-IS26] Biogeochemistry

Thu. May 28, 2015 9:00 AM - 10:45 AM 104 (1F)

Convener:*Muneoki Yoh(Tokyo University of Agriculture and Technology), Shibata, Hideaki(Field Science Center fot Northern Biosphere, Hokkaido University), Naohiko Ohkouchi(Japan Agency for Marine-Earth Science and Technology), Youhei Yamashita(Faculty of Environmental Earth Science, Hokkaido University), Chair:Chisato Yoshikawa(Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology), Takuro Nunoura(Research and Development Center for Marine Biosciences, Japan Agency for Marine-Earth Science & Technology (JAMSTEC))

10:15 AM - 10:30 AM

[MIS26-06] Benthic prokaryote community and their roles on biogeochemical cycles under the oxygen minimum zone

*Hidetaka NOMAKI1, Takuro NUNOURA1, Miho HIRAI1, Juliarni JULIARNI1, Yoshihiro TAKAKI1, Kentaro INOUE2, Hisami SUGA1 (1.JAMSTEC, 2.The University of Tokyo)

Keywords:Oxygen minimum zone, sedimentary microbes, nitrogen cycle

We investigated the impacts of the oxygen minimum zone (OMZ) on the benthic prokaryotic communities and biogeochemical cycles off India. Surface sediments were collected from three sites; core of the OMZ (water depth of 530 m), lower part of the OMZ (water depth of 800 m), and lower boundary of the OMZ (water depth of 1150 m). Porewater nutrient concentrations, organic matter contents, and diversity and abundances of microbial SSU rRNA and their functional genes were examined using the sediment cores down to 10 cm depth. In situ experiments using 13C-labeled bicarbonate were also carried out at the same stations to evaluate carbon fixation rates at each site. The results demonstrated variability of benthic microbial communities with different carbon fixation rate across oxygen gradient of the bottom water.