Japan Geoscience Union Meeting 2015

Presentation information

International Session (Oral)

Symbol B (Biogeosciences) » B-PT Paleontology

[B-PT03] Biocalcification and the Geochemistry of Proxies -Field ecology, Laboratory culture and Paleo

Tue. May 26, 2015 11:00 AM - 12:45 PM 104 (1F)

Convener:*Takashi Toyofuku(Japan Agency for Marine-Earth Science and Technology (JAMSTEC)), Hiroshi Kitazato(Institute of Biogeosciences (BioGeos),Japan Agency for Marine-Earth Science and Technology (JAMSTEC)), Jelle Bijma(Alfred-Wegener-Institut fur Polar- und Meeresforschung), Chair:Jelle Bijma(Alfred-Wegener-Institut fur Polar- und Meeresforschung)

11:54 AM - 12:09 PM

[BPT03-09] Mathematical analysis of proton, carbon, and calcium transport during calcification process of benthic foraminifera

*Miki Y. MATSUO1, Takashi TOYOFUKU1, Hide SAKAGUCHI1, NOOIJER, Lennart J. DE2 (1.Japan Agency for Marine-Earth Science and Technology, 2.Utrecht University)

Keywords:benthic foraminifera, calcification, proton transport, mathematical analysis

Foraminifera are marine unicellular organism responsible for approximately 50% of today's ocean calcium carbonate production, which implies that they play a considerable role in the global carbon cycle in ocean chemistry. However, we have not fully understood how their calcifications proceed and change their chemical environment.
To understand the calcification process, we investigate the dynamics of the pH around the foraminifer. The visualized spatial pH distribution shows that the calcification accompanies a rapid decrease of the surrounding pH, which implies that the calcification accompanies active proton pumping. The resultant spatial pH distribution is used to estimate the flux of proton released out of the protective envelope. Combing the estimated proton flux and the calcium carbonate responsible for a new chamber, we propose that the proton/H+ exchange process is the key process driving the foraminiferal calcification.