Organization
Institute of Graduate School Education Support . Specially Appointed Professor
Title
Specially Appointed Professor
External link
KANDA Jota
Degree
-
Doctor of Science ( 1987.3 The University of Tokyo )
-
Master of Science ( 1984.3 The University of Tokyo )
-
Bachelor of Science ( 1982.3 The University of Tokyo )
Research Areas
-
Environmental Science/Agriculture Science / Environmental dynamic analysis / Chemical Oceanography
Research History (researchmap)
-
Niigata University Institute of Graduate Education Support Specially Appointed Professor
2024.9
-
Tokyo University of Marine Science and Technology Dean of Faculty
2016.2 - 2021.3
-
Tokyo University of Marine Science and Technology Vice President
2015.4 - 2021.3
-
Tokyo University of Marine Science and Technology Professor
2008.4 - 2024.8
-
Tokyo University of Marine Science and Technology Associate Professor
2003.10 - 2008.3
-
Tokyo University of Fisheries Associate Professor
2000.12 - 2003.9
-
Shizuoka University Associate Professor
1994.4 - 2000.11
-
The University of Tokyo Assistant Professor
1989.2 - 1994.3
Research History
-
Niigata University Institute of Graduate School Education Support Specially Appointed Professor
2024.9
-
Tokyo University of Marine Science and Technology Department of Ocean Sciences Professor
2008.4 - 2024.8
-
Tokyo University of Marine Science and Technology Department of Ocean Sciences Associate Professor
2003.10 - 2008.3
-
Tokyo University of Fisheries Department of Ocean Sciences Associate Professor
2000.12 - 2003.9
-
Shizuoka University Faculty of Science Associate Professor
1995.10 - 2000.11
-
Shizuoka University Faculty of Liberal Arts Associate Professor
1994.4 - 1995.9
-
The University of Tokyo Ocean Research Institute Research Assistant
1989.2 - 1994.3
Education
-
The University of Tokyo Graduate School of Science Doctor Course (Major in Botany)
1984.4 - 1987.3
-
The University of Tokyo Graduate School of Science Master Course (Major in Botany)
1982.4 - 1984.3
-
The University of Tokyo Faculty of Science Department of Botany
1978.4 - 1982.3
Professional Memberships
-
THE OCEANOGRAPHIC SOCIETY OF JAPAN
-
THE JAPANESE-FRENCH OCEANOGRAPHIC SOCIETY
Committee Memberships
-
Japan Science and Technology Agency Research Supervisor, Blue Biosphere/PRESTO
2023.4
-
The Oceanographic Society of Japan President
2019.4 - 2023.3
Papers
-
Temporal variations in the surface primary productivity and their causes at a station F3 in the inner Tokyo Bay
Issei Hamana, Chiho Sukigara, Naho Horimoto-Miyazaki, Fuminori Hashihama, Michiyo Yamamoto-Kawai, Jota Kanda
Journal of Oceanography 79 ( 3 ) 253 - 264 2023.6
-
Succession of three dominant diatoms, Skeletonema, Thalassiosira, and Pseudo-nitzschia in the inner area of Tokyo Bay from 2003 to 2017 Reviewed
Yo Ueno, Mai Takano, Toshiya Katano, Kenji Yoshino, Naho Miyazaki-Horimoto, Saori Yasui-Tamura, Chiho Sukigara, Issei Hamana, Fuminori Hashihama, Jota Kanda, Takashi Ishimaru
Journal of Oceanography 2023.2
-
Benthic food web structures as an explanation for prolonged ecological half-life of <sup>137</sup>Cs in flatfish species in the Fukushima coastal area
Isak Holmerin, Filip Svensson, Toru Hirawake, Takashi Ishimaru, Yukari Ito, Jota Kanda, Francisco Nascimento, Clare Bradshaw
Journal of Environmental Radioactivity 246 2022.5
-
Shoaling of abyssal ventilation in the Eastern Indian Sector of the Southern Ocean Reviewed
Communications Earth & Environment 3 ( 120 ) 2022.5
-
Fuminori Hashihama, Ichiro Yasuda, Aki Kumabe, Mitsuhide Sato, Hiroshi Sasaoka, Yosuke Iida, Takuhei Shiozaki, Hiroaki Saito, Jota Kanda, Ken Furuya, Philip W. Boyd, Masao Ishii
Nature Communications 12 ( 1 ) 2021.6
-
First isolation and analysis of caesium-bearing microparticles from marine samples in the Pacific coastal area near Fukushima Prefecture. International journal
Hikaru Miura, Takashi Ishimaru, Yukari Ito, Yuichi Kurihara, Shigeyoshi Otosaka, Aya Sakaguchi, Kazuhiro Misumi, Daisuke Tsumune, Atsushi Kubo, Shogo Higaki, Jota Kanda, Yoshio Takahashi
Scientific reports 11 ( 1 ) 5664 - 5664 2021.3
-
Ocean Acidification State in the Highly Eutrophic Tokyo Bay, Japan: Controls on Seasonal and Interannual Variability
Michiyo Yamamoto-Kawai, Soichiro Ito, Haruko Kurihara, Jota Kanda
FRONTIERS IN MARINE SCIENCE 8 2021.3
-
Cross-basin differences in the nutrient assimilation characteristics of induced phytoplankton blooms in the subtropical Pacific waters Reviewed
Fuminori Hashihama, Hiroaki Saito, Taketoshi Kodama, Saori Yasui-Tamura, Jota Kanda, Iwao Tanita, Hiroshi Ogawa, E. Malcolm S. Woodward, Philip W. Boyd, Ken Furuya
Biogeosciences 18 ( 3 ) 897 - 915 2021.2
-
Coastal urbanization alters carbon cycling in Tokyo Bay
Atsushi Kubo, Jota Kanda
Scientific Reports 10 ( 1 ) 2020.12
-
Automated simultaneous determination of total dissolved nitrogen and phosphorus in seawater by persulfate oxidation method
Saori Yasui-Tamura, Fuminori Hashihama, Hiroshi Ogawa, Takashi Nishimura, Jota Kanda
Talanta Open 2 100016 - 100016 2020.12
-
Changes in radioactive cesium concentrations from 2011 to 2017 in Fukushima coastal sediments and relative contributions of radioactive cesium-bearing microparticles. International journal
Atsushi Kubo, Kai Tanabe, Yukari Ito, Takashi Ishimaru, Mayumi Otsuki, Hisayuki Arakawa, Yutaka W Watanabe, Hikaru Miura, Daisuke Tsumune, Jota Kanda
Marine pollution bulletin 161 ( Pt B ) 111769 - 111769 2020.12
-
Biogeochemical Controls of Particulate Phosphorus Distribution Across the Oligotrophic Subtropical Pacific Ocean
Fuminori Hashihama, Hiroaki Saito, Takuhei Shiozaki, Makoto Ehama, Shuhei Suwa, Takanori Sugiyama, Haruka Kato, Jota Kanda, Mitsuhide Sato, Taketoshi Kodama, Tamaha Yamaguchi, Sachiko Horii, Iwao Tanita, Shota Takino, Kazutaka Takahashi, Hiroshi Ogawa, Philip W. Boyd, Ken Furuya
GLOBAL BIOGEOCHEMICAL CYCLES 34 ( 9 ) 2020.9
-
Effects of phytoplankton community composition and productivity on sea surface pCO(2) variations in the Southern Ocean
Shintaro Takao, Shin-Ichiro Nakaoka, Fuminori Hashihama, Keishi Shimada, Hisayuki Yoshikawa-Inoue, Toru Hirawake, Jota Kanda, Gen Hashida, Koji Suzuki
DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS 160 2020.6
-
Reconstruction of radiocesium levels in sediment off Fukushima: Simulation analysis of bioavailability using parameters derived from observed 137Cs concentrations
Yutaka Tateda, Kazuhiro Misumi, Daisuke Tsumune, Michio Aoyama, Yasunori Hamajima, Jota Kanda, Takashi Ishimaru, Tatsuo Aono
Journal of Environmental Radioactivity 214-215 106172 - 106172 2020.4
-
Noriko Takeda, Fuminori Hashihama, Jota Kanda
Talanta 208 120371 2020.2
-
Spatial variation in sedimentary radioactive cesium concentrations in Tokyo Bay following the Fukushima Daiichi Nuclear Power Plant accident. Reviewed International journal
Atsushi Kubo, Kai Tanabe, Yukari Ito, Takashi Ishimaru, Hisayuki Arakawa, Jota Kanda
Chemosphere 235 550 - 555 2019.11
-
Hirofumi Tazoe, Takeyasu Yamagata, Kazuki Tsujita, Hisao Nagai, Hajime Obata, Daisuke Tsumune, Jota Kanda, Masatoshi Yamada
International Journal of Environmental Research and Public Health 16 ( 21 ) 4094 - 4094 2019.10
-
Arsenate and microbial dynamics in different phosphorus regimes of the subtropical Pacific Ocean Reviewed
Hashihama Fuminori, Suwa Shuhei, Kanda Jota, Ehama Makoto, Sakuraba Ryousuke, Kinouchi Shinko, Sato Mitsuhide, Yamaguchi Tamaha, Saito Hiroaki, Ogura Yoshitoshi, Hayashi Tetsuya, Mori Hiroshi, Kurokawa Ken, Suzuki Shotaro, Hamasaki Koji
PROGRESS IN OCEANOGRAPHY 176 2019.9
-
Biogeochemical controls of surface ocean phosphate Reviewed
Martiny Adam C, Lomas Michael W, Fu Weiwei, Boyd Philip W, Chen Yuh-ling L, Cutter Gregory A, Ellwood Michael J, Furuya Ken, Hashihama Fuminori, Kanda Jota, Karl David M, Kodama Taketoshi, Li Qian P, Ma Jian, Moutin Thierry, Woodward, E. Malcolm S, Moore J. Keith
SCIENCE ADVANCES 5 ( 8 ) 2019.8
-
Mechanisms of radiocesium depuration in Sebastes cheni derived by simulation analysis of measured Cs-137 concentrations off southern Fukushima 2014-2016 Reviewed
Ishimaru Takashi, Tateda Yutaka, Tsumune Daisuke, Aoyama Michio, Hamajima Yasunori, Kasamatsu Nobue, Yamada Manabu, Yoshimura Takashi, Mizuno Takuji, Kanda Jota
JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 203 200 - 209 2019.7
-
Examination of the Catabolic Rates of 13C-Labeled Fatty Acids Bound to the α and β Positions of Triacylglycerol Using 13CO2 Expired from Mice. Reviewed
Kazuaki Yoshinaga, Fumiaki Beppu, Yoshio Yamatani, Atsushi Kubo, Aya Yoshinaga-Kiriake, Toshiharu Nagai, Akihiko Yoshida, Jota Kanda, Naohiro Gotoh
Journal of oleo science 68 ( 6 ) 591 - 598 2019.6
-
Long-term variability of nutrient and dissolved organic matter concentrations in Tokyo Bay between 1989 and 2015 Reviewed
Kubo Atsushi, Hashihama Fuminori, Kanda Jota, Horimoto-Miyazaki Naho, Ishimaru Takashi
LIMNOLOGY AND OCEANOGRAPHY 64 S209 - S222 2019.1
-
Effect of calcium treatment on catabolic rates of <sup>13</sup>c-labeled fatty acids bound to the α and β positions of triacylglycerol Reviewed
Kazuaki Yoshinaga, Fumiaki Beppu, Yoshio Yamatani, Atsushi Kubo, Aya Yoshinaga-Kiriake, Toshiharu Nagai, Akihiko Yoshida, Jota Kanda, Naohiro Gotoh
Journal of Oleo Science 68 ( 11 ) 1149 - 1155 2019
-
Morphological features and mixing states of soot-containing particles in the marine boundary layer over the Indian and Southern oceans Reviewed
Sayako Ueda, Kazuo Osada, Keiichiro Hara, Masanori Yabuki, Fuminori Hashihama, Jota Kanda
Atmospheric Chemistry and Physics 18 ( 13 ) 9207 - 9224 2018.7
-
Radioactive cesium concentrations in coastal suspended matter after the Fukushima nuclear accident Reviewed
Atsushi Kubo, Kai Tanabe, Genta Suzuki, Yukari Ito, Takashi Ishimaru, Nobue Kasamatsu-Takasawa, Daisuke Tsumune, Takuji Mizuno, Yutaka W. Watanabe, Hisayuki Arakawa, Jota Kanda
Marine Pollution Bulletin 131 341 - 346 2018.6
-
I-4. Radioactive contamination of the marine ecosystem off Fukushima Reviewed
Ishimaru Takashi, Ito Yukari, Kanda Jota
NIPPON SUISAN GAKKAISHI 84 ( 6 ) 1108 2018
-
Factors controlling <sup>134</sup>Cs activity concentrations in sediment collected off the coast of Fukushima Prefecture in 2013–2015 Reviewed
Miho Fukuda, Tatsuo Aono, Shinnosuke Yamazaki, Takashi Ishimaru, Jota Kanda, Jun Nishikawa, Shigeyoshi Otosaka
Geochemical Journal 52 ( 2 ) 201 - 209 2018
-
Liquid waveguide spectrophotometric measurements of arsenate and particulate arsenic, as well as phosphate and particulate phosphorus, in seawater Reviewed
Fuminori Hashihama, Shuhei Suwa, Jota Kanda
JOURNAL OF OCEANOGRAPHY 73 ( 4 ) 439 - 447 2017.8
-
Dietary Starfish Oil Prevents Hepatic Steatosis and Hyperlipidemia in C57BLI6N Mice Fed High-fat Diet Reviewed
Fumiaki Beppu, Haoqi Li, Kazuaki Yoshinaga, Toshiharu Nagai, Akihiko Yoshinda, Atsushi Kubo, Jota Kanda, Naohiro Gotoh
JOURNAL OF OLEO SCIENCE 66 ( 7 ) 761 - 769 2017.7
-
A significant net sink for CO2 in Tokyo Bay Reviewed
Atsushi Kubo, Yosaku Maeda, Jota Kanda
SCIENTIFIC REPORTS 7 2017.3
-
Dissolved radiocaesium in seawater off the coast of Fukushima during 2013-2015 Reviewed
Miho Fukuda, Tatsuo Aono, Shinnosuke Yamazaki, Jun Nishikawa, Shigeyoshi Otosaka, Takashi Ishimaru, Jota Kanda
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY 311 ( 2 ) 1479 - 1484 2017.2
-
Biokinetics of radiocesium depuration in marine fish inhabiting the vicinity of the Fukushima Dai-ichi Nuclear Power Plant Reviewed
Yutaka Tateda, Daisuke Tsumune, Kazuhiro Misumi, Tatsuo Aono, Jota Kanda, Takashi Ishimaru
JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 166 67 - 73 2017.1
-
Comparison of Catabolic Rates of sn-1, sn-2, and sn-3 Fatty Acids in Triacylglycerols Using (CO2)-C-13 Breath Test in Mice Reviewed
Fumiaki Beppu, Takashi Kawamatsu, Yoshio Yamatani, Toshiharu Nagai, Kazuaki Yoshinaga, Hoyo Mizobe, Akihiko Yoshida, Atsushi Kubo, Jota Kanda, Naohiro Gotoh
JOURNAL OF OLEO SCIENCE 66 ( 1 ) 85 - 91 2017.1
-
Seasonal variations and sources of sedimentary organic carbon in Tokyo Bay Reviewed
Atsushi Kubo, Jota Kanda
MARINE POLLUTION BULLETIN 114 ( 2 ) 637 - 643 2017.1
-
Comparison of 13C-labeled fatty acid catabolic rates bound to the sn-1, sn-2, and sn-3 positions of triacylglycerol using 13C-labeled CO2 expired from mice. Reviewed
F. Beppu, T. Kawamatsu, Y. Yamatani, T. Nagai, K. Yoshinaga, H. Mizobe, A. Yoshida, A. Kubo, J. Kanda, N. Gotoh
J. Oleo Sci. 66 85 - 91 2017
-
Seasonal variations of dissolved organic matter and nutrients in sediment pore water in the inner part of Tokyo Bay Reviewed
Saori Yasui, Jota Kanda, Toshihiro Usui, Hiroshi Ogawa
JOURNAL OF OCEANOGRAPHY 72 ( 6 ) 851 - 866 2016.12
-
Sensitive determination of total particulate phosphorus and particulate inorganic phosphorus in seawater using liquid waveguide spectrophotometry Reviewed
Makoto Ehama, Fuminori Hashihama, Shinko Kinouchi, Jota Kanda, Hiroaki Saito
TALANTA 153 66 - 70 2016.6
-
Blue carbon in human-dominated estuarine and shallow coastal systems Reviewed
Tomohiro Kuwae, Jota Kanda, Atsushi Kubo, Fumiyuki Nakajima, Hiroshi Ogawa, Akio Sohma, Masahiro Suzumura
AMBIO 45 ( 3 ) 290 - 301 2016.4
-
Status of Cs-137 contamination in marine biota along the Pacific coast of eastern Japan derived from a dynamic biological model two years simulation following the Fukushima accident Reviewed
Yutaka Tateda, Daisuke Tsumune, Takaki Tsubono, Kazuhiro Misumi, Masatoshi Yamada, Jota Kanda, Takashi Ishimaru
JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 151 495 - 501 2016.1
-
Trans-octadecenoic Acid Positional Isomers Have Different Accumulation and Catabolism Properties in Mice Reviewed
Fumiaki Beppu, Masaharu Asanuma, Yoshinori Kawamura, Toshiharu Nagai, Kazuaki Yoshinaga, Hoyo Mizobe, Koichi Kojima, Satoshi Kasatani, Koji Nagao, Atsushi Kubo, Jota Kanda, Naohiro Gotoh
JOURNAL OF OLEO SCIENCE 64 ( 11 ) 1159 - 1167 2015.11
-
Liquid waveguide spectrophotometric measurement of nanomolar ammonium in seawater based on the indophenol reaction with o-phenylphenol (OPP) Reviewed
Fuminori Hashihama, Jota Kanda, Ami Tauchi, Taketoshi Kodama, Hiroaki Saito, Ken Furuya
TALANTA 143 374 - 380 2015.10
-
Radiocesium biokinetics in olive flounder inhabiting the Fukushima accident-affected Pacific coastal waters of eastern Japan Reviewed
Yutaka Tateda, Daisuke Tsumune, Takaki Tsubono, Tatsuo Aono, Jota Kanda, Takashi Ishimaru
JOURNAL OF ENVIRONMENTAL RADIOACTIVITY 147 130 - 141 2015.9
-
Calcium carbonate saturation and ocean acidification in Tokyo Bay, Japan Reviewed
Michiyo Yamamoto-Kawai, Natsuko Kawamura, Tsuneo Ono, Naohiro Kosugi, Atsushi Kubo, Masao Ishii, Jota Kanda
JOURNAL OF OCEANOGRAPHY 71 ( 4 ) 427 - 439 2015.8
-
Seasonal variations in concentration and lability of dissolved organic carbon in Tokyo Bay Reviewed
Kubo A, Yamamoto-Kawai M, Kanda J
Biogeosciences 12 ( 1 ) 269 - 279 2015
-
Radiological impact of TEPCO's Fukushima Dai-ichi Nuclear Power Plant accident on invertebrates in the coastal benthic food web Reviewed
Tadahiro Sohtome, Toshihiro Wada, Takuji Mizuno, Yoshiharu Nemoto, Satoshi Igarashi, Atsushi Nishimune, Tatsuo Aono, Yukari Ito, Jota Kanda, Takashi Ishimaru
Journal of Environmental Radioactivity 138 106 - 115 2014.8
-
Selective depressions of surface silicic acid within cyclonic mesoscale eddies in the oligotrophic western North Pacific Reviewed
Fuminori Hashihama, Jota Kanda, Yousaku Maeda, Hiroshi Ogawa, Ken Furuya
DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS 90 115 - 124 2014.8
-
Release of Pu Isotopes from the Fukushima Daiichi Nuclear Power Plant Accident to the Marine Environment Was Negligible Reviewed
Wenting Bu, Miho Fukuda, Jian Zheng, Tatsuo Aono, Takashi Ishimaru, Jota Kanda, Guosheng Yang, Keiko Tagami, Shigeo Uchida, Qiuju Guo, Masatoshi Yamada
ENVIRONMENTAL SCIENCE & TECHNOLOGY 48 ( 16 ) 9070 - 9078 2014.8
-
Observation of radionuclides in Marine Biota off the coast of Fukushima prefecture after TEPCO’s Fukushima Daiichi nuclear power station accident Reviewed
Tatsuo Aono, Yukari Ito, Tadahiro Sohtome, Takuji Mizuno, Satoshi Igarashi, Satoshi Igarashi, Jota Kanda, Takashi Ishimaru
Radiation Monitoring and Dose Estimation of the Fukushima Nuclear Accident 115 - 123 2014.1
-
Pu distribution in the marine sediments within the 30 km zone around the Fukushima Daiichi Nuclear Power Plant site. Reviewed
W. Bu, M. Fukuda, J. Zheng, T. Aono, T. Ishimaru, J. Kanda, G. Yang, K. Tagami, G. Yang, S. Uchida, Q. Guo, M. Yamada
Proceedings of the 15th Workshop on Environmental Radioactivity, KEK, Tsukuba, Japan, March 6-8, 2014. pp. 329-334. 2014
-
Sensitive determination of enzymatically labile dissolved organic phosphorus and its vertical profiles in the oligotrophic western North Pacific and East China Sea Reviewed
Fuminori Hashihama, Shinko Kinouchi, Shuhei Suwa, Masahiro Suzumura, Jota Kanda
JOURNAL OF OCEANOGRAPHY 69 ( 3 ) 357 - 367 2013.6
-
Developing partnerships with the community for coastal ESD Reviewed
Midori Kawabe, Hiroshi Kohno, Reiko Ikeda, Takashi Ishimaru, Osamu Baba, Naho Horimoto, Jota Kanda, Masaji Matsuyam, Masato Moteki, Yayoi Oshima, Tsuyoshi Sasaki, Minlee Yap
INTERNATIONAL JOURNAL OF SUSTAINABILITY IN HIGHER EDUCATION 14 ( 2 ) 122 - 132 2013
-
Continuing 137 Cs release to the sea from the fukushima dai-ichi nuclear power plant through 2012 Reviewed
J. Kanda
Biogeosciences 10 ( 9 ) 6107 - 6113 2013
-
Comparison of catabolism rate of fatty acids to carbon dioxide in mice Reviewed
Ryosuke Shibata, Naohiro Gotoh, Atsushi Kubo, Jota Kanda, Toshiharu Nagai, Hoyo Mizobe, Kazuaki Yoshinaga, Koichi Kojima, Hiroyuki Watanabe, Shun Wada
EUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY 114 ( 12 ) 1340 - 1344 2012.12
-
Tracking the Fukushima Radionuclides Reviewed
Naohiro Yoshida, Jota Kanda
SCIENCE 336 ( 6085 ) 1115 - 1116 2012.6
-
Brominated methane compounds and isoprene in surface seawater of Sagami Bay: Concentrations, fluxes, and relationships with phytoplankton assemblages Reviewed
Michiko Kurihara, Motoko Iseda, Teru Ioriya, Naho Horimoto, Jota Kanda, Takashi Ishimaru, Yukuya Yamaguchi, Shinya Hashimoto
MARINE CHEMISTRY 134 71 - 79 2012.4
-
The Oceanography Course at the Tokyo University of Marine Science and Technology and certificate of oceanographic observation Reviewed
Jota Kanda
Nippon Suisan Gakkaishi (Japanese Edition) 78 ( 3 ) 525 - 526 2012
-
Limiting factors of phytoplankton communities along the ogasawara transect in north western pacific ocean
Mathias Girault, Hisayuki Arakawa, Kanda Jota
Mer 49 ( 3-4 ) 93 - 101 2011.12
-
Occurrence of rain-origin nitrate patches at the nutrient-depleted surface in the East China Sea and the Philippine Sea during summer Reviewed
Taketoshi Kodama, Ken Furuya, Fuminori Hashihama, Shigenobu Takeda, Jota Kanda
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS 116 2011.8
-
Occurrence of rain-origin nitrate patches at the nutrient-depleted surface in the East China Sea and the Philippine Sea during summer Reviewed
Taketoshi Kodama, Ken Furuya, Fuminori Hashihama, Shigenobu Takeda, Jota Kanda
Journal of Geophysical Research: Oceans 116 ( 8 ) 2011
-
Mesoscale decrease of surface phosphate and associated phytoplankton dynamics in the vicinity of the subtropical South Pacific islands Reviewed
Fuminori Hashihama, Mitsuhide Sato, Shigenobu Takeda, Jota Kanda, Ken Furuya
DEEP-SEA RESEARCH PART I-OCEANOGRAPHIC RESEARCH PAPERS 57 ( 3 ) 338 - 350 2010.3
-
New estimation of N-2 fixation in the western and central Pacific Ocean and its marginal seas Reviewed
Takuhei Shiozaki, Ken Furuya, Taketoshi Kodama, Satoshi Kitajima, Shigenobu Takeda, Toshihiko Takemura, Jota Kanda
GLOBAL BIOGEOCHEMICAL CYCLES 24 2010.3
-
Education for sustainable development for Tokyo Bay: Developing a practice framework of university-based coastal ESD Reviewed
Midori Kawabe, Hiroshi Kohno, Takashi Ishimaru, Osamu Baba, Naho Horimoto, Reiko Ikeda, Jota Kanda, Takafumi Kudo, Masaji Matsuyama, Masato Moteki, Yayoi Oshima, Tsuyoshi Sasaki
MARINE POLICY 33 ( 4 ) 720 - 725 2009.7
-
Role of environment and hydrography in determining the picoplankton community structure of Sagami Bay, Japan Reviewed
Smita Mitbavkar, Toshiro Saino, Naho Horimoto, Jota Kanda, Takashi Ishimaru
JOURNAL OF OCEANOGRAPHY 65 ( 2 ) 195 - 208 2009.4
-
Latitudinal distribution of diazotrophs and their nitrogen fixation in the tropical and subtropical western North Pacific Reviewed
Satoshi Kitajima, Ken Furuya, Fuminori Hashihama, Shigenobu Takeda, Jota Kanda
LIMNOLOGY AND OCEANOGRAPHY 54 ( 2 ) 537 - 547 2009.3
-
Macro-scale exhaustion of surface phosphate by dinitrogen fixation in the western North Pacific Reviewed
Fuminori Hashihama, Ken Furuya, Satoshi Kitajima, Shigenobu Takeda, Toshihiko Takemura, Jota Kanda
GEOPHYSICAL RESEARCH LETTERS 36 2009.2
-
Size fraction and class composition of phytoplankton in the Antarctic marginal ice zone along the 140°E meridian during February-March 2003
Hashihama Fuminori, Hirawake Toru, Kudoh Sakae, Kanda Jota, Furuya Ken, Yamaguchi Yukuya, Ishimaru Takashi
Polar science 2 ( 2 ) 109 - 120 2008.6
-
Vertical profiles of nitrate uptake obtained from in situ N-15 incubation experiments in the western North Pacific Reviewed
Jota Kanda
JOURNAL OF MARINE SYSTEMS 71 ( 1-2 ) 63 - 78 2008.5
-
Temporal variation in phytoplankton composition related to water mass properties in the central part of Sagami Bay Reviewed
Fuminori Hashihama, Naho Horimoto, Jota Kanda, Ken Furuya, Takashi Ishimaru, Toshiro Saino
JOURNAL OF OCEANOGRAPHY 64 ( 1 ) 23 - 37 2008.2
-
Vertical profiles of trace nitrate in surface oceanic waters of the North Pacific Ocean and East China Sea
Jota Kanda, Takayuki Itoh, Motomune Nomura
Mer 45 ( 2 ) 69 - 80 2007.5
-
KITAZATO H.
Progress in Oceanography 57 3 - 16 2003.6
-
Particle dynamics in the deep water column of Sagami Bay, Japan. I: Origins of apparent flux of sinking particles Reviewed
T. Nakatsuka, T. Masuzawa, J. Kanda, H. Kitazato, Y. Shirayama, M. Shimanaga, A. Yamaoka
Progress in Oceanography 57 ( 1 ) 31 - 45 2003
-
Environmental control of nitrate uptake in the East China Sea Reviewed
Jota Kanda, Takayuki Itoh, Daisuke Ishikawa, Yasunori Watanabe
Deep-Sea Research Part II: Topical Studies in Oceanography 50 ( 2 ) 403 - 422 2003
-
Seasonal and annual variation in the primary production regime in the central part of Sagami Bay Reviewed
Jota Kanda, Shiho Fujiwara, Hiroshi Kitazato, Yoshihiro Okada
Progress in Oceanography 57 ( 1 ) 17 - 29 2003
-
New production in the East China Sea, comparison between well-mixed winter and stratified summer conditions Reviewed
Yuh-Ling Lee Chen, Houng-Yung Chen, Wen-Huei Lee, Chin-Chang Hung, George T.F. Wong, Jota Kanda
Continental Shelf Research 21 ( 6-7 ) 751 - 764 2001
-
Seasonal phytodetritus deposition and responses of bathyal benthic foraminiferal populations in Sagami Bay, Japan: Preliminary results from 'Project Sagami 1996-1999' Reviewed
H. Kitazato, Y. Shirayama, T. Nakatsuka, S. Fujiwara, M. Shimanaga, Y. Kato, Y. Okada, J. Kanda, A. Yamaoka, T. Masuzawa, K. Suzuki
Marine Micropaleontology 40 ( 3 ) 135 - 149 2000
-
New production and F-ratio on the continental shelf of the East China Sea: Comparisons between nitrate inputs from the subsurface Kuroshio current and the Changjiang river Reviewed
Y. L. Lee Chen, H. B. Lu, F. K. Shiah, G. C. Gong, K. K. Liu, J. Kanda
Estuarine, Coastal and Shelf Science 48 ( 1 ) 59 - 75 1999
-
Primary production in the East China Sea Reviewed
Furuya K, Hama T, Kanda J, Odate T
Bulletin on Coastal Oceanography 36 ( 1 ) 19 - 28 1998.8
-
Application of an automated carbon-nitrogen analyzer for elemental and isotopic analysis of samples retained on glass-fiber filters Reviewed
Jota Kanda, Keiko Sada, Isao Koike, Katsumi Yokouchi
International Journal of Environmental Analytical Chemistry 72 ( 3 ) 163 - 171 1998
-
Determination of experimentally enriched 15N in nitrate nitrogen based on an improved method of azo dye formation Reviewed
Hideki Yakushiji, Jota Kanda
Journal of Oceanography 54 ( 4 ) 337 - 342 1998
-
Measurements of the Nitrogen Budget in the Rotifer Brachionus plicatilis by Using 15N Reviewed
Shigeru Aoki, Akinori Hino, Jota Kanda
Fisheries Science 61 ( 3 ) 406 - 410 1995
-
Determination of ammonium in seawater based on the indophenol reaction with o-phenylphenol (OPP) Reviewed
Jota Kanda
Water Research 29 ( 12 ) 2746 - 2750 1995
-
Biological Activity and Flux of Carbon and Nitrogen in the Ocean.
RADIOISOTOPES 43 ( 4 ) 263 - 264 1994
-
Studies of nitrogen assimilation by marine phytoplankton and its implication in the nitrogen cycling in the sea - Lecture by the member awarded the Okada Prize of the Oceanographical Society of Japan for 1990 Reviewed
Jota Kanda
Journal of the Oceanographical Society of Japan 46 ( 6 ) 314 - 327 1990.12
-
Specific growth rates and grazing mortality of chroococcoid cyanobacteria Synechococcus spp. in pelagic surface waters in the sea Reviewed
Sakae Kudoh, Jota Kanda, Masayuki Takahashi
Journal of Experimental Marine Biology and Ecology 142 ( 3 ) 201 - 212 1990.10
-
Ammonium uptake and synthesis of cellular nitrogenous macromolecules in phytoplankton Reviewed
Jota Kanda, Akihiko Hattori
Limnology and Oceanography 33 ( 6 ) 1568 - 1579 1988
-
Nitrogen nutrition and physiological state of natural populations of phytoplankton in surface waters of the western Pacific Ocean Reviewed
Jota Kanda, Toshiro Saino, Akihiko Hattori
Limnology and Oceanography 33 ( 6 ) 1580 - 1585 1988
-
Instrumental Achievements a Revolver Inlet for Elemental Analyzer Reviewed
Toshiro Saino, Jota Kanda, Toshiro Yamada
Analytical Sciences 3 ( 3 ) 279 - 280 1987
-
H+ and k+ efflux associated with nh4+ Uptake in Anabaena Cylindrica Cells in the Dark Reviewed
Masayuki Ohmori, Jota Kanda
The Journal of General and Applied Microbiology 33 ( 4 ) 311 - 319 1987
-
Variation of carbon and nitrogen uptake capacity in a regional upwelling area around Hachijo Island Reviewed
Jota Kanda, Toshiro Saino, Akihiko Hattori
Journal of the Oceanographical Society of Japan 41 ( 6 ) 373 - 380 1985.12
-
Nitrogen uptake by natural populations of phytoplankton and primary production in the Pacific Ocean: Regional variability of uptake capacity Reviewed
Jota Kanda, Toshiro Saino, Akihiko Hattori
Limnology and Oceanography 30 ( 5 ) 987 - 999 1985
MISC
-
Nanomolar nutrient supply drives net community production in the western subtropical North Pacific
橋濱史典, 安田一郎, 隈部あき, 佐藤光秀, 笹岡洋志, 飯田洋介, 塩崎拓平, 齊藤宏明, 神田穣太, 古谷研, BOYD Philip W., 石井雅男
日本地球化学会年会要旨集(Web) 70th 2023
-
上田紗也子, 長田和雄, 原圭一郎, 矢吹正教, 橋濱史典, 神田穣太
エアロゾル科学・技術研究討論会(CD-ROM) 35th ( 18 ) ROMBUNNO.A303 - 9224 2018.7
-
田辺魁, 久保篤史, 鈴木元太, 伊藤友加里, 石丸隆, 津旨大輔, 水野拓治, 荒川久幸, 神田穣太
日本海洋学会大会講演要旨集 2017 77 2017.9
-
Chlorophyll a concentration of phytoplankton during Umitaka-maru cruises of the 55–57th Japanese Antarctic Research Expedition in 2014–2016
Makabe R, Iida T, Moteki M, Kanda J, Odate T
JARE DATA REPORTS (Marine Biology) ( 63 ) 1 - 12 2017.6
-
Evaluation of desorption of radioactive cesium from suspended particles during its transport from river water to seawater by General Adsorption Model (GAM)
Miura Hikaru, Qiaohui Fan, Kurihara Yuichi, Sakaguchi Aya, Higaki Shogo, Ishimaru Takashi, Kanda Jota, Takahashi Yoshio
Abstracts of Annual Meeting of the Geochemical Society of Japan 63 ( 0 ) 43 - 43 2016
-
トランス脂肪酸異性体間の組織への蓄積と異化効率の違い
別府史章, 浅沼公晴, 河村芳徳, 永井利治, 吉永和明, 溝部帆洋, 小島浩一, 笠谷聡, 永尾晃治, 久保篤史, 神田穣太, 後藤直宏
日本栄養・食糧学会大会講演要旨集 70th 2016
-
Cesium-137 Budget and Ecological Transfer in the Coastal Marine Environment of Fukushima
56 ( 4 ) 240 - 244 2014.4
-
Effect of Radionuclides on Marine Environment
35 ( 2 ) 105 - 109 2014.3
-
海から見た福島第1原子力発電所事故 : 依然として存在する海洋汚染の危険性 (特集 福島原発とどう向き合うか)
神田 穣太
Business i. ENECO = ビジネスアイエネコ : エネルギーと地球環境の明日を考える経済専門誌 47 ( 2 ) 28 - 31 2014.2
-
Jota Kanda, Masao Ishii, Hiroshi Ogawa, Tsuneo Ono, Hajime Obata, Michiyo Yamamoto-Kawai, Masahiro Suzumura, Makio C. Honda, Youhei Yamashita, Yutaka W. Watanabe, Graduate Faculty of Marine Sciences Tokyo University of Marine Science and Technology, Meteorological Research Institute Japan Meteorological Agency, Atmosphere and Ocean Research Institute The University of Tokyo, Fisheries Research Agency, Atmosphere and Ocean Research Institute The University of Tokyo, Research Center for Advanced Science and Technology Tokyo University of Marine Science and Technology, National Institute of Advanced Industrial Science and Technology, Japan Agency for Marine-Earth Science and Technology, Faculty of Environmental Earth Science Hokkaido University, Faculty of Environmental Earth Science Hokkaido University
22 ( 6 ) 219 - 251 2013.11
-
Current status of radionuclide release to the sea from the Fukushima Dai-ichi Nuclear Power Plant
83 ( 11 ) 1284 - 1286 2013.11
-
神田 穣太
科学 83 ( 6 ) 634 - 638 2013.6
-
南北太平洋貧栄養海域における易分解性溶存有機態リンの空間分布
櫻庭涼輔, 橋濱史典, 諏訪修平, 神田穣太, 齊藤宏明, 津田敦, 児玉武稔, 佐藤光秀
日本海洋学会大会講演要旨集 2013 133 2013.3
-
南北太平洋貧栄養海域におけるヒ酸塩およびリン酸塩の空間分布
諏訪修平, 橋濱史典, 神田穣太, 児玉武稔, 齊藤宏明, 津田敦
日本海洋学会大会講演要旨集 2013 132 2013.3
-
KANDA Jota
41 ( 2 ) 21 - 28 2012.7
-
インド洋・南極海でのエアロゾル粒子生成イベントと先駆ガス濃度
長田和雄, 上田紗也子, 上田紗也子, 原圭一郎, 神田穣太, 橋濱史典, 笠松伸江, 笠松伸江, 中岡慎一郎, 中岡慎一郎, 和田誠
極域科学・宙空圏・気水圏・生物・地学シンポジウム講演予稿集(CD-ROM) 2011 2011
-
P430 南インド洋・南極海洋上で観測されたスス粒子(ポスター・セッション)
上田 紗也子, 長田 和雄, 神田 穣太, 橋濱 史典
大会講演予講集 99 423 - 423 2011
-
HASHIHAMA Fuminori, KANDA Jota
La mer. 47 ( 4 ) 119 - 127 2010.3
-
Particle dynamics in the deep water column of Sagami Bay, Japan. II: seasonal change in profiles of suspended phytodetritus
T Nakatsuka, J Kanda, H Kitazato
PROGRESS IN OCEANOGRAPHY 57 ( 1 ) 47 - 57 2003
-
Models on Nutrient Limitation of Uptake and Growth of Microalgae : Variability of Half-Saturation Constants
KANDA JOTA
日本微生物生態学会報 8 ( 2 ) 109 - 123 1993.10
Awards
-
The JOS Environmental Science Prize
2014.4 The Oceanographic Society of Japan
Jota KANDA
-
The Japanese-French Oceanographic Society Award
2013.6 The Japanese-French Oceanographic Society
-
The Okada Prize
1990.4 The Oceanographic Society of Japan
Jota KANDA
Research Projects
-
Sensitive determination of nanomolar urea and its dynamics in oligotrophic ocean
Grant number：17H01852
2017.4 - 2022.3
System name：Grants-in-Aid for Scientific Research
Research category：Grant-in-Aid for Scientific Research (B)
Awarding organization：Japan Society for the Promotion of Science
Hashihama Fuminori
Grant amount：\17290000 （ Direct Cost: \13300000 、 Indirect Cost：\3990000 ）
This study investigated whether urea is a major nitrogen source for sustaining net communiy production in the oligotrophic ocean, using a newly-developed sensitive analytical system for determining trace urea. In the nitrate-depleted subtropical ocean, urea existed at nanomolar level and was utilized by microbes as revealed by urease gene analysis and urea-15N uptake experiment. However, annual budget analysis of various nitrogen components demonstrated that net community production was sustained by not only urea but also other dissolved organic nitrogen.
-
Cosmogenic radiotracer study of phosphorus cycling in oligotrophic subtropical ocean
Grant number：15H02802
2015.4 - 2020.3
System name：Grants-in-Aid for Scientific Research
Research category：Grant-in-Aid for Scientific Research (B)
Awarding organization：Japan Society for the Promotion of Science
Kanda Jota
Grant amount：\13650000 （ Direct Cost: \10500000 、 Indirect Cost：\3150000 ）
The present study revealed a phosphorus (P) cycling in the western subtropical North Pacific during summer, using cosmogenic radiotracers of 32-P and 33-P and nanomolar concentrations of ambient dissolved and particulate P pools. In the euphotic zone of the study area, trace concentrations of dissolved and particulate P showed spatially uniform distributions, while 33-P/32-P in dissolved P and size-fractionated particulate P pools showed spatially inconsistent distributions. These results suggest that despite of homogeneous ambient P pool concentrations, P cycling varies dynamically in the summer western subtropical North Pacific.
-
Interdisciplinary Study on Environmental Transfer of Radionuclides from the Fukushima Daiichi NPP Accident
Grant number：24110001
2012.6 - 2017.3
System name：Grants-in-Aid for Scientific Research
Research category：Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
Awarding organization：Japan Society for the Promotion of Science
Onda Yuichi
Grant amount：\74100000 （ Direct Cost: \57000000 、 Indirect Cost：\17100000 ）
1.Mutual awareness and information sharing within the domain: supervised the research of the whole planning research group to proceed smoothly. We tried closer cooperation among all the members by utilizing the WEB conference system. 2.Research support activities: We oversee the "Database Working Group" and organized environmental data, modeling data, and analytical data after the accident in an easy-to-use manner and provided it to related researchers. We also supervised the "analysis team" and reflected the results of the proficiency test so that the analysis would be an IAEA standard. 3.Public offering: We conducted research support on the publicly-offered projects adopted for complementing and promoting each planned research.
-
Transfer and accumulation of radioactive material in marine ecosystem
Grant number：24110005
2012.6 - 2017.3
System name：Grants-in-Aid for Scientific Research
Research category：Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
Awarding organization：Japan Society for the Promotion of Science
Kanda Jota, MORIYA Shigeharu, KOBAYASHI Takuya, YOSHIMURA Takeshi, ISHIMARU Takashi, IGARASHI Satoshi, SUGA Jiro, YAMAKAWA Hiroshi, OTSU Hideaki, ITO Yukari, TAKAZAWA Nobue, UCHIYAMA Kaori, KUBO Atshushi
Grant amount：\100230000 （ Direct Cost: \77100000 、 Indirect Cost：\23130000 ）
Radioactive material derived from the Fukushima Daiichi Nuclear Power Plant accident was investigated in marine ecosystem. 1) For radioactive cesium in marine organisms and environment in the coastal area of Fukushima, we obtained a continuous time-series data set by ship observations twice a year. Time-series data set for radioactive cesium in zooplankton was also obtained in several open ocean areas. 2) Examinations of transfer routes of radioactive cesium in coastal rocky seafloor revealed that transition of radioactive cesium from suspended or descending particles, and from organic fraction of sediments was small. 3) Using the on-site observation data, the transition of radioactive cesium in the ecosystem was reproduced by a numerical model, and the model was applied to prediction of the future trend of the radioactivity level of marine organisms.
-
Updates of long-term monitoring parameters for detection of future biogeochemical changes in Tokyo Bay
Grant number：24510009
2012.4 - 2015.3
System name：Grants-in-Aid for Scientific Research
Research category：Grant-in-Aid for Scientific Research (C)
Awarding organization：Japan Society for the Promotion of Science
KANDA Jota
Grant amount：\5200000 （ Direct Cost: \4000000 、 Indirect Cost：\1200000 ）
For more than 20 years, standard hydrographic observations have been conducted monthly in Tokyo bay by Tokyo University of Marine Science and Technology. Since a drastic change in biogeochemical setting is anticipated because of the continuing decrease of nutrient load into the bay, we have tested updates of our monthly monitoring with introduction of several new parameters. The tested parameters include alkaline phosphatase activity, carbonate parameters, primary production and nitrogen uptake, and denitrification (anammox) activity. The incorporation of these parameters are demonstrated to be very useful in detecting the nutrient-limitation events in the bay.
-
Coastal ESD-development and practice of Tokyo Bay model
Grant number：24310028
2012.4 - 2015.3
System name：Grants-in-Aid for Scientific Research
Research category：Grant-in-Aid for Scientific Research (B)
Awarding organization：Japan Society for the Promotion of Science
KOHNO Hiroshi, ISHIMARU Takashi, KANDA Jyota, KAWABE Midori, BABA Osamu, MOTEKI Masato
Grant amount：\16250000 （ Direct Cost: \12500000 、 Indirect Cost：\3750000 ）
This study aims to show a framework of plan-making discussion about sustainable use of Tokyo Bay by a collaboration between coastal communities and university. The following researches were carried out for achieving the purpose.
1) ‘Fact-sheets’ on water qualities, planktons, fishes, algae and birds in Tokyo Bay were printed for using texts of activities. 2) Seven science papers were published, and seven oral/poster presentations in scientific meetings were presented. 3) Lectures on the history and present status of Tokyo Bay were given many times to coastal community-citizens. 4) Operated workshops and scientific cafe and on many aspects of Tokyo Bay numbered 31 times. 5) A participatory action research program, "Minato-jyuku", taking for 2-4 days was continued for three years.
Through the above-mentioned activities, an initial framework for community-university partnerships for discussion about sustainable use of Tokyo Bay can be shown. -
Spatial and temporal variation of carbon dioxide budget in Tokyo Bay
Grant number：20510005
2008 - 2010
System name：Grants-in-Aid for Scientific Research
Research category：Grant-in-Aid for Scientific Research (C)
Awarding organization：Japan Society for the Promotion of Science
KANDA Jota
Grant amount：\4680000 （ Direct Cost: \3600000 、 Indirect Cost：\1080000 ）
Underway observations of carbon dioxide (CO_2) partial pressure were conducted in Tokyo Bay, and budget of CO_2 between surface water and atmosphere was evaluated。 At the innermost, low-salinity waters of the bay, CO_2 was continuously released to atmosphere due to oversaturation。 In most parts of the bay, however, CO_2 was taken up extensively during spring and summer, presumably by net photosynthesis of organic matter, and was nearly close to atmospheric equilibrium during autumn and winter。 The entire bay was a significant net sink of atmospheric CO_2。
-
Studies on the Changes in Environment and Ecosystem in the Antarctic Ocean
Grant number：19255014
2007 - 2009
System name：Grants-in-Aid for Scientific Research
Research category：Grant-in-Aid for Scientific Research (A)
Awarding organization：Japan Society for the Promotion of Science
ISHIMARU Takashi, YAMAGUCHI Yukuya, KOIKE Yoshio, KURITA Yoshihiro, YOSHIDA Jiro, KANDA Jota, TANAKA Yuji, TSUCHIYA Kotaro, KITADE Yujiro, MOTEKI Masato, HORIMOTO Naho, HIRAWAKE Toru, KASAMATSU Nobue
Grant amount：\32110000 （ Direct Cost: \24700000 、 Indirect Cost：\7410000 ）
-
DETAILED VARIATIONS IN BIOACTIVE ELEMENTS IN THE SURFACE OCEAN AND THEIR INTERACTION WITH MICROBIOLOGICAL PROCESSES
Grant number：18067007
2006 - 2010
System name：Grants-in-Aid for Scientific Research
Research category：Grant-in-Aid for Scientific Research on Priority Areas
Awarding organization：Japan Society for the Promotion of Science
OGAWA Hiroshi, KOGURE Kazuhiro, KANDA Jota, SUZUMURA Masahiro, HASHIHAMA Fuminori
Grant amount：\77200000 （ Direct Cost: \77200000 ）
Some new methods for measuring carbon, nitrogen and phosphorus in seawater were developed and applied to in situ observations in the ocean. Consequently, the detailed knowledge on biogeochemical cycles in surface ocean was obtained. In particular, by greatly modifying the conventional methods for nutrients and organic matter, novel images of biogeochemical cycles in surface ocean were successfully brought.
-
Dynamics of carbon dioxide uptake and nutrients in subtropical oceanic waters
Grant number：17510005
2005 - 2007
System name：Grants-in-Aid for Scientific Research
Research category：Grant-in-Aid for Scientific Research (C)
Awarding organization：Japan Society for the Promotion of Science
KANDA Jota
Grant amount：\3850000 （ Direct Cost: \3700000 、 Indirect Cost：\150000 ）
Spatial variations of trace concentrations of nutrients and partial pressure of carbon dioxide (pCO_2) were compared for surface waters of the subtropical ocean. For this purpose, a pCO_2 monitoring system with high resolution of temporal variation was designed, and its performance was tested from 2005 through 2006. The developed system was carried onboard RAT Umitaka-maru of the Tokyo University of Marine Science and Technology, and surface monitoring in the subtropical waters was conducted during the period from 29 Nov to 14 Dec. in 2006, on a cruise leg from Tokyo to Sydney. Along with pCO_2 monitoring, the continuous observation of pH by colorimetric determination and the high-sensitive continuous flow analysis of nutrients were also performed. The pCO_2 showed variations of smaller spatial scales (〜tens of km), and these variations were categorized into three patterns. The first pattern accompanies decrease of temperature, increase of salinity, and increase of nutrient concentrations, which can be ascribed to enhanced vertical mixing and/or upwelling. The second pattern accompanies an extensive decrease of salinity and may reflect dilution of seawater by precipitation. The third and most frequently observed pattern was co-variation of pCO_2 and trace phosphate, which was presumably caused by biological activity
-
貧栄養海域におけるシアノバクテリア-珪藻共生体の動態と窒素固定
Grant number：17651003
2005 - 2006
System name：科学研究費助成事業
Research category：萌芽研究
Awarding organization：日本学術振興会
古谷 研, 武田 重信, 神田 穣太
Grant amount：\3300000 （ Direct Cost: \3300000 ）
2005年5-6月の「みらい」航海における東経149度上の34゜N-2゜Nから得られた試料の解析と、2006年9月の「淡青丸」航海でフィリピン海西部から単離された窒素固定者培養株を用いた実験的解析を行った。R.intracelularis共生体は28゜30'N-31゜10'Nにかけて顕著に多く、海水中の全窒素固定量はこの海域から北赤道海流域にかけてが最も高かった。28゜30'N以南では2-10umの単細胞性シアノバクテリア(ナノシアノバクテリア)が主たる窒素固定者で、海域によって窒素固定者が異なることが明らかになった。我々が単離した株は、夜間窒素固定を行い、その日間固定量は1.2-1.8nmolN cell^<-1>と、共生体よりも一桁以上低い活性であった。この値を東経149度上に当てはめると、ナノシアノバクテリアは、現存量が共生体よりも大きいことから28゜30'Nから北赤道海流域で主要な窒素固定者となっていたものいえる。
海域による窒素固定活性の違いは、他の植物プランクトンとの栄養塩競合を介して、栄養塩濃度の分布に影響を及ぼすと考えられるため、東経149度上において高感度検出法によりナノモルレベルの栄養塩濃度測定を行った。硝酸塩+亜硝酸塩(N+N)濃度は研究海域全域で20nM以下と海域間での差はなかった。一方、溶存反応性リン酸塩(SRP)濃度は、北赤道海流の北側で10nM以下と低く、南側では40-80nMと有意に高かった。これは、北赤道海流の北側では活発な窒素固定活性によりSRPがほぼ枯渇状態になったのに対して、南側では窒素固定活性が低いため、SRPが消費され尽くしていなかったためである考えられ、窒素固定者の分布の偏りが、SR濃度の海盆スケールでの地理分布構造に寄与していると結論された。 -
Ecosystem and Oceanographic Structure in the Indian Sector of the Antarctic Ocean
Grant number：14255012
2002 - 2005
System name：Grants-in-Aid for Scientific Research
Research category：Grant-in-Aid for Scientific Research (A)
Awarding organization：Japan Society for the Promotion of Science
ISHIMARU Takashi, YAMAGUCHI Yukuya, NAGASHIMA Hideki, KANDA Jota, MOTEKI Masato, HIRAWAKE Tohru
Grant amount：\39390000 （ Direct Cost: \30300000 、 Indirect Cost：\9090000 ）
Three cruises by T/V Umitaka-Maru were conducted in the Indian sector of the Antaractic Ocean in 2002/03, 2004/05, 2005/06 austral summer. Survey areas were the eastern shelf of Keruguelen plateau and off Wilkes Land, off Lutzow-Holm Bay and off Wilkes Land and off Luzow-Holm Bay, respectively. Main themes were the circulation of deep water formed off Adelie Land, the relationships between surface ecosystems and physical and chemical environments and the relationships between surface ecosystems and mesopelagic ecosystems. Hydrographic observations were conducted by using ship mount ADCP, CTD and LADCP, and seawater was sampled from various depths for macro-nutrient and trace metal analyses. Bio-optical observations, measurements of primary production and collections of surface phytoplankton and zooplankton by a plankton net and mesopelagic organisms by a multiple opening/closing trawl were also conducted. Aerosol observations were carried out off Luzow-Holm Bay, coincide with those from the Showa Station. A Continuous Plankton Recorder was towed during cruising from each port to observation area for the study on the long term change of surface plankton communities in combination with samples collected by R/V Aurora Australis and R/V Shirase.
Until now, papers on following topics have been published : on the pathway and volume of deepwater formed off Adelie Land ; on the remote sensing observations of eddies and annual variability of chlorophyll and sea-ice around the Antarctic Divergence ; on the parameters for precise estimation of Antarctic Krill biomass by quantitative echo-sounder. Inter-annual changes in community composition and biomass of zooplankton along 140゜E meridian related to the development of the Antarctic Divergence and the meander of the Antarctic Circumpolar Current were elucidated and some of the results will be submitted soon. Analyses of trace metals, aerosols and photosynthetic pigments are still undergoing. Mesopelagic organisms have been sorted into major taxa and detailed studies are also still undergoing. -
鉄供給による貧栄養海域の窒素固定および有機物移出生産の制御
Grant number：14658151
2002 - 2003
System name：科学研究費助成事業
Research category：萌芽研究
Awarding organization：日本学術振興会
古谷 研, 神田 穣太, 武田 重信
Grant amount：\3300000 （ Direct Cost: \3300000 ）
昨年度東シナ海から得たTrichodesmium単離株を加えた培養株の窒素固定能の評価、熱帯・亜熱帯海域の窒素固定能とその鉄濃度およびリン酸濃度依存性、およびRichelia intracellulalisの生態に関して成果を得た。
Synechocystis培養株は明期に全く活性を示さず暗期にのみ活性が検出されたが、飽和光量下で1.3pM/μgChla/hと、同一条件下でのTrichodesmiumの最大活性90pM/μgChla/hに比べて著しく低かった。海産Synechocystisの窒素固定能に関する知見は極めて乏しく、今回の結果がこのグループの特性をどの程度代表するかについて今後海洋からの単離株を精力的に集めて精査する必要がある。
天然群集の活性については白鳳丸KH03-1航海において東部太平洋20°N-20°Sにおいて2003年6-8月に調査した。その結果、ハワイ東方海域のみで活性が検出された。溶存鉄およびリン酸塩の添加実験から、鉄添加に対して夜間は明瞭な正の活性応答が認められたが昼間には全くなかった。これに対してリン酸塩添加では、昼夜とも応答が認められたが夜間により高い活性であった。試水中の組成から、昼の応答は主にRichelia、夜間はSynechocystisのものと考えられ、両者には鉄やリン酸塩濃度依存性において明瞭な違いがあることが分かった。この結果は2004年2月にハワイ南方海域の海鷹丸航海でも確認された。
Chaecoceros compressusに細胞外共生するRicheliaの出現海域を昨年度に継続して調べた結果、共生体は外洋水と沿岸水の境界にのみ出現し、大型珪藻Rhizosolenia cleveiの細胞内共生者に由来する可能性が示唆された。 -
A highly sensitive and detailed vertical distribution of nutrients in surface oceanic waters as a basis for evaluation of carbon dioxide absorption flux
Grant number：13680600
2001 - 2003
System name：Grants-in-Aid for Scientific Research
Research category：Grant-in-Aid for Scientific Research (C)
Awarding organization：Japan Society for the Promotion of Science
KANDA Jota
Grant amount：\2600000 （ Direct Cost: \2600000 ）
A highly sensitive method was developed for colorimetric analysis of nutrients in seawater by combining a continuous flow analysis system and a long path-length capillary flow cell (LWCC). With a 2-m light path cell, the detection limit of phosphate in seawater was 2.8nM. Interference with silicate and arsenate was examined and arsenate was to found to affect significantly unless a reduction reagent for arsenate was added. During several cruises of R/V Umitaka-maru and R/V Shinyo-maru, detailed vertical distributions of nutrients within surface or euphotic layers were determined. For stratified and oligotrophic waters, the highly sensitive colorimetric method was applied in phospate analysis. Nitrate (+nitrite) was analyzed by a highly sensitive chemiluminescence method. Detailed profiles of nutrients were obtained by conventional colorimetric analysis in the Southern Ocean during a Umitaka-maru cruise in January-February 2003. In these observations, the depth at which nutrient concentration begins to increase (or the depth of top of the nutricline) was found to be shallower for phosphate than for nitrate within the mixed layer. These features may reflect the general pattern of difference between nitrogen and phosphate dynamics in shallow oceanic waters. The highly sensitive colorimetric analysis of these nutrients can be used in high sensitive surface monitoring of nutrients and onboard incubation experiments.
-
Selective consumption and taphonomy by benthic organisms at sediemnt-water interface --Establishment of new paleoceanographic prixies through experimental methods--
Grant number：11440154
1999 - 2001
System name：Grants-in-Aid for Scientific Research
Research category：Grant-in-Aid for Scientific Research (B)
Awarding organization：Japan Society for the Promotion of Science
KITAZATO Hiroshi, NAKATSUKA Takeshi, SHIRAYAMA Yoshihisa, WADA Hideki
Grant amount：\15200000 （ Direct Cost: \15200000 ）
This research aims to trace consumption process of sinking organic matter by benthic orgamisms at Sediment-Water Interface (SWI) both through in situ and laboratory experiments. Field experiments were carried out both at Sagami Bay and Tanabe Bay. 1. Suspended organic matters in benthic nepheloid layer were collected by manned submersible. Organic conpositions were measured by gas chromatograph for identification. 2. Surface undisturbed sediments were collected with multiple corer. Core samples were sliced every 0.25 cm. Geochemical analyzes were made for characterizing chemical environments. Biomasses of meiobenthos were estimated according to faunal compositions. 3. In situ feeding experiments were carried out at Sagami Bay with manned submersible "Shinkai 2000". Single celled alga that were labelled with carbon 13 were supplied as food materials. 4. Both respiration rates and biomasses were measured at the laboratory. Remineralization rates of organic carbon by meiobenthos were calculated from intake rates, biomass and respiration rates.
Benthic organisms respond to sinking organic materials according to their own microhabitat preferences. For instance, shallow infaunal species respond rapidly and intake large ammount of organic matter. Numbers of benthic foraminifera changes in harmony to lipid contents within sediments, even though response differ from species to species. More than 50 % of sinking organic matters were consumed by benthic meiofauna. It is clear that benthic organisms play a large role at deep sea ecosystems around SWI. -
Dynamics of Sediment-Water Interface
Grant number：08304032
1996 - 1998
System name：Grants-in-Aid for Scientific Research
Research category：Grant-in-Aid for Scientific Research (A)
Awarding organization：Japan Society for the Promotion of Science
KITAZATO Hiroshi, KATO Yoshihisa, KANDA Jota, NAKATSUKA Takeshi, MASUZAWA Toshiyuki, SHIRAYAMA Yoshihisa
Grant amount：\27700000 （ Direct Cost: \27700000 ）
"Benthic-pelagic coupling" is a key aspect of both material cycles and ecology in oligotrophic deep-sea floor environments, However, it remains unclear whether "bentho-pelagic coupling" exists in eutrophic deep-sea environments. Eutrophic deep-sea environments are mainly located along ocean margins. Interdisciplinary research was carried out to understand seasonal carbon cycling in a eutrophic deep-sea environment along the western margin of the Pacific, in Sagami Bay, central Japan. We collected data from surface water samples, satellite photographs, sediment trap moorings and multiple core samplings at the permanent station in the central part of Sagami Bay between 1997 and 1998. Bottom nepheloid layers were also observed through video images, which were recorded at a real-time deep-sea floor observatory off Hatsushima in Sagami Bay.
Distinct spring blooms were observed during mid-February through May in 1997. Mass fluxes deposited in sediment traps did not show distinct signals of spring blooms because of the influence of resuspended materials. However, dense clouds of suspended particles were observed only in the spring in benthic nepheloid layer. This phenomena corresponds well to the increase of phytodetrital matters after the spring bloom. A phytodetrital layer started to form on the sediment surface about two weeks after the start of the spring bloom. Chlorophyll-alpha was detected in the top 2 cm of the sediment only during presence of a phytodetritus layer. Protozoan and metazoan meiobenthos increased in densities after phytodetritus deposition. "Benthic-pelagic coupling" was certainly observed even in a eutrophic marginal ocean environment. -
超微量分析法による海洋表層における硝酸態窒素の高精度鉛直分布の解析
Grant number：07640655
1995
System name：科学研究費助成事業
Research category：一般研究(C)
Awarding organization：日本学術振興会
神田 穣太
Grant amount：\2200000 （ Direct Cost: \2200000 ）
高感度減圧化学発光検出器(アナテックヤナコECL-88-US-D)を導入し、化学発光法による超微量硝酸態窒素の分析システムを開発した。導入した検出器は従来研究代表者が使用していたものより感度が2桁程度高く、またシグナル強度の安定性が極めて高い。さらに試料処理部に改良を加え、10ポートバルブを用いて2流路系を切り替えることにより試料処理速度を倍増させると共に、試料導入部にオートマティックディスペンサーを使用することにより試料水の導入体積を厳密に制御できるようにした。この結果、硝酸態窒素100nMレベルでの繰り返し測定誤差を1nM(10回測定)以下にすることができた。一方、平成7年8月の東京大学海洋研究所「淡青丸」研究航海において紀伊半島沖の黒潮海域で、また11月の海洋科学技術センター「かいよう」研究航海で東シナ海で観測を行った。これらの観測では光合成有効放射、植物色素、水温、塩分、密度などの鉛直連続プロファイルを得ると共に、硝酸濃度躍層付近を中心に5-10mおきに硝酸態窒素測定用の試料を採取した。この試料は採取後直ちにスルファニルアミド処理を行って大気中のNOxによる汚染を防ぎ、凍結して研究室に持ち帰った。現在のところ前述の分析システムを用いて硝酸態窒素濃度の測定を行うと共に、測定が終了して硝酸態窒素濃度の鉛直分布のデータが得られた観測点について、有光層の鉛直物理構造、生物消費の鉛直構造などの関係について定量的な解析を試みている段階である。
-
海洋表層における硝酸の消費および供給速度の推定
Grant number：06740420
1994
System name：科学研究費助成事業
Research category：奨励研究(A)
Awarding organization：日本学術振興会
神田 穣太
Grant amount：\1200000 （ Direct Cost: \1200000 ）
本年度導入したクロマトデータ処理装置,現有の前処理ライン、および本学理学部から借用した化学発光検出器を用い、新たに化学発光法による硝酸態窒素の超微量分析システムの構成を行った。本年度導入した超純水製造装置を用いて作成した硝酸態窒素の微量標準試料を用いた検討の結果、試料量10mlにおいては10nMにおける繰り返し分析精度(SD)が1.3nMで分析できることが確かめられた。これは海洋有光層における硝酸濃度分析に十分適用できると判断された。一方、平成6年8月3日から31日まで、海洋科学技術センター「かいよう」の航海に乗船し、沖縄近海、および東シナ海陸棚域で、硝酸態窒素濃度分析用試料を採取すると同時に、15-N安定同位体標識実験を実施した。硝酸態窒素濃度分析試料はスルファニルアミド処理後凍結保存して持ち帰った。また安定同位体標識実験試料も凍結して持ち帰り、凍結乾燥後、微量化学天秤を用いて所定の助燃剤等を添加して分析試料を調整した。この試料は東京大学海洋研究所において同位体分析を実施した。これらの結果は現在解析中であるが、航海実施中の天候の都合で、生物活性の比較的高い陸棚域を中心に実験を行ったため、実験時間中に硝酸態窒素(含トレーサー)が消費され尽くした場合が多かった。得られたデータから硝酸の消費速度を推定する手順を確立すると同時に、この点の再検討を実施中である。
-
新生産フラックスと植物プランクトンの硝酸同化制御機構
Grant number：05216203
1993
System name：科学研究費助成事業
Research category：重点領域研究
Awarding organization：日本学術振興会
神田 穣太
Grant amount：\1200000 （ Direct Cost: \1200000 ）
化学発光法による海水中の硝酸態・亜硝酸態窒素の分析システムを構成した。この分析システムについて、分析条件、分析精度、分析確度、試料の取り扱い方法などについて検討した。これらの検討をふまえ、分析システムを1993年10月14日から12月3日まで行われた東京大学海洋研究所白鳳丸KH-93-4次航海に塔載した。亜熱帯外洋域に属する観測点B(24ﾟ 35'N、170ﾟ 00'E)、C(22ﾟ 45'N、158ﾟ 05'W)において、1)有光層内の硝酸態または硝酸態プラス亜硝酸態窒素の鉛直分布の測定、2)現場法による^<15>NO_3^-取り込み実験(Bのみ)、3)船上インキュベーターでの^<15>NO_3^-取り込み速度の時間変化の測定、を行った。化学発光法による鉛直分布の測定結果から、両測点ともに有光層内の硝酸態窒素濃度は10nM以下であり、100から110mの間の数mで濃度が急激に上昇し始めることがわかった。いずれの場合でも、硝酸態窒素濃度が立ち上がる深さはクロロフィル極大の約5m上、相対光量子束0.5-1.0%に相当した。超微量分析による亜熱帯外洋域での有光層内の硝酸濃度の鉛直分布は従来測定された例がなかった。本研究で得られた不連続な濃度分布は、ある特定の深度を境に硝酸態窒素の消費速度が大きく異なっていることを示唆する。一方、化学発光法による分析から^<15>N取り込み実験における硝酸トレーサーの希釈が正確に算出でき、従って現場での硝酸同化速度が初めて算出できた。これらの結果を総合することにより、硝酸の供給と消費の動態を議論するために基礎となる情報が得られた。
-
新生産フラックスと植物プランクトの硝酸同化制御機構
Grant number：04232206
1992
System name：科学研究費助成事業
Research category：重点領域研究
Awarding organization：日本学術振興会
神田 穣太
Grant amount：\1200000 （ Direct Cost: \1200000 ）
植物プランクトンの硝酸同化は硝酸濃度、アンモニア濃度、光の3つの主要な環境要因によって制御されると考えられる。この制御機構を明らかにすることは海洋における新生産フラックスの規模と変動についての解析を行う上で不可欠である。この制御機構の研究は現場の自然群集についての研究と培養藻類による室内実験系と用いた研究を平行して行う必要がある。これまでの研究代表者の研究で、貧栄養環境の自然群集について、硝酸を添加後約10時間で活発な硝酸同化が現れてくることが明らかになった。このときのアンモニア濃度は検出限界以下であったことから、従来よくいわれている1〜2μM以上のアンモニアの存在による硝酸同化の抑制とその解除とは異なった現象である可能性がある。今年度は比較のため海岸域の海水に栄養塩類を添加して珪藻の人為ブルームを発生させる系を用い、その過程での硝酸取込みの推移をモニターする実験を行った。この結果、珪藻ブルームの系ではアンモニア濃度の低下が硝酸取込みをすみやかに誘導する、従来の知見と合致した結果から得られた。貧栄養海域の現象を生理学的に解析するため、単細胞性ラン藻Synehococcnssp.(StrainSYN)の連続培養系も確立するとともに、基本的な増殖パラメータの定置を行った。また連続培養系か貧栄養海域での実験を行う上で技術的な制約となっている硝酸およびアンモニアのナノモルレベルの分析システムの開発・検討を行った。硝酸については減圧化学発光法で必要な感度を有する分析システムを構成し、方法を確立した。またアンモニアについてはオルトフェニルフェノールを用いたインドフュノール改変法を開発し、新たに固相抽出を組み合わせる方法でナノモルレベルの分析が可能であることを確めた。