Haruka Takagi
Waseda University
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Featured researches published by Haruka Takagi.
Paleontological Research | 2016
Haruka Takagi; Kazuyoshi Moriya; Toyoho Ishimura; Atsushi Suzuki; Hodaka Kawahata; Hiromichi Hirano
Abstract. The stable carbon (δ13C) and oxygen isotopes (δ18O) of planktic foraminiferal tests have been widely used as proxies in paleoceanography and paleoclimatology. The ontogenetic isotopic profiles of foraminifers are also thought to record ecological information about species, such as changes in habitat depth and symbiotic relationships. However, isotopic profiles during “individual ontogeny” have rarely been examined. In this study, we report the ontogenetic isotopic information for three net-collected modern species, Globigerinoides sacculifer, Neogloboquadrina dutertrei, and Globorotalia inflata, together with several in situ oceanographic parameters of the water column in Sagami Bay, Japan (seawater temperature, salinity, nutrients, chlorophyll a content, δ13C of dissolved inorganic carbon [DIC], and δ18O of seawater). We examined the ontogenetic profiles of the foraminifers with chamber dissection and chamber-by-chamber analyses of δ13C and δ18O using a specially designed continuous-flow mass spectrometry system. The ontogenetic δ18O profiles showed overall 18O-enrichment in all three species, suggesting their ontogenetic migration toward deeper habitats. When these records were compared with the physicochemical profiles of the water column, all the ontogenetic records began within the uppermost thermocline or shallower, corresponding to the depth of relatively high chlorophyll content. Later in ontogeny, Gs. sacculifer and N. dutertrei migrated to the bottom of the level of maximum chlorophyll, whereas Gr. inflata descended to a depth of 200 m. The deviations of foraminiferal δ13C from the δ13C of DIC were largest in the juvenile stages, but were near zero at a test mass of ca. 10 μg for all three species. Contrary to the subsequent asymptotic profiles of this deviation in N. dutertrei and Gr. inflata, Gs. sacculifer alone showed a subsequent increase, of up to +1.0‰, reflecting its symbiotic relationship. We conclude that a certain ontogenetic test mass, in this case of around 10 μg, can be assigned to a preferable size class of foraminifers from which to reconstruct the paleo-δ13C of DIC in the water column, regardless of the species ecology.
Integrated Ocean Drilling Program: Preliminary Reports (342) pp. 1-263. (2012) | 2012
Richard D. Norris; Paul A. Wilson; Peter Blum; Annick Fehr; Claudia Agnini; André Bornemann; Slah Boulila; Paul R. Bown; Cécile Cournède; Oliver Friedrich; Amit K. Ghosh; Christopher J. Hollis; Pincelli M. Hull; Kyoungnam Jo; Christopher K. Junium; Masanori Kaneko; Diederik Liebrand; Peter C. Lippert; Zhonghui Liu; Hiroki Matsui; Kazuyoshi Moriya; Hiroshi Nishi; Bradley N. Opdyke; Donald E. Penman; Brian W. Romans; Howie D. Scher; Philip F. Sexton; Haruka Takagi; Sandra Kirtland Turner; Jessica H. Whiteside
Paleobiology | 2015
Haruka Takagi; Kazuyoshi Moriya; Toyoho Ishimura; Atsushi Suzuki; Hodaka Kawahata; Hiromichi Hirano
Marine Micropaleontology | 2016
Haruka Takagi; Katsunori Kimoto; Tetsuichi Fujiki; Atsushi Kurasawa; Kazuyoshi Moriya; Hiromichi Hirano
Journal of Plankton Research | 2014
Tetsuichi Fujiki; Haruka Takagi; Katsunori Kimoto; Atsushi Kurasawa; Tomoko Yuasa; Yoshihisa Mino
Scientific Drilling | 2013
Peter B. Flemings; Peter J. Polito; Thomas L. Pettigrew; Gerardo J. Iturrino; Eric Meissner; Robert Aduddell; Donald L. Brooks; Chris Hetmaniak; David Huey; John T. Germaine; Richard D. Norris; Paul A. Wilson; Peter Blum; Annick Fehr; Claudia Agnini; André Bornemann; Slah Boulila; Paul R. Bown; Cécile Cournède; Oliver Friedrich; Amit K. Ghosh; Christopher J. Hollis; Pincelli M. Hull; K. Jo; Christopher K. Junium; Masanori Kaneko; Diederik Liebrand; Peter C. Lippert; Z. Liu; Hiroki Matsui
Symbiosis | 2018
Haruka Takagi; Katsunori Kimoto; Tetsuichi Fujiki; Kazuyoshi Moriya
Marine Micropaleontology | 2018
Masako Hori; Kotaro Shirai; Katsunori Kimoto; Atsushi Kurasawa; Haruka Takagi; Akizumi Ishida; Naoto Takahata; Yuji Sano
Japan Geoscience Union | 2017
Haruka Takagi; Katsunori Kimoto; Tetsuichi Fujiki; Hiroaki Saito
Japan Geoscience Union | 2016
Haruka Takagi; Kazuyoshi Moriya; Toyoho Ishimura
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National Institute of Advanced Industrial Science and Technology
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