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Takahashi Keigo D.
| Faculty of Fisheries Sciences Marine Bioresource and Environmental Science Marine Environmental Science | Specially Appointed Assistant Professor |
Researcher basic information
■ Degree■ URL
researchmap URLホームページURL■ Various IDs
Researcher number
- 90985350
Career
■ CareerCareer
- Apr. 2026 - Present
Hokkaido University, Faculty of Fisheries Sciences, JSPS Special Assistant Professor, Japan - Apr. 2025 - Mar. 2026
Hokkaido University, Faculty of Fisheries Sciences, JSPS Research Fellow PD - Apr. 2024 - Mar. 2025
Hokkaido University, Field Science Center for Northern Biosphere, JSPS Research Fellow PD, Japan - Apr. 2023 - Mar. 2024
Soka University, Faculty of Science and Engineering, JSPS Research Fellow PD (Switched from DC), Japan
- Apr. 2019 - Mar. 2023, The Graduate University for Advanced Studies, School of Multidisciplinary Sciences, Department of Polar Science, Japan
- Apr. 2017 - Mar. 2019, The Graduate School of Tokyo Universiity of Marine Science and Technology, Course of Marine Resources and Environment, Japan
Research activity information
■ Awards- May 2019, The Japanese Society of Diatomology, Best Presentation Award
Ice-algal communities in the Antarctic coastal regions during sea-ice forming season
Keigo Takahashi;Masato Ito;Ryosuke Makabe;Masato Moteki;Tsuneo Odate
- Stable isotope signatures, concentrations, and potential supply of particulate organic carbon and nitrogen from summer sea ice in the Indian sector of the Southern Ocean
Keigo D. Takahashi; Ryosuke Makabe; Masayoshi Sano; Kazuki Nakata; Noriaki Kimura; Daiki Nomura; Michiyo Yamamoto-Kawai; Ryo Matsuda; Natsumi Nojiro; Masato Ito; Shintaro Takao; Naho Horimoto-Miyazaki; Aiko Tachibana; Norio Kurosawa; Takeshi Tamura; Mizuki Komatsu; Kay I. Ohshima; Kohei Mizobata; Shigeru Aoki; Masato Moteki
EGUsphere, Copernicus GmbH, 20 May 2026, [Lead author, Corresponding author]
English, Scientific journal, Abstract. The primary production and zooplankton life cycles in the Southern Ocean synchronize with seasonal sea ice melting, during which particulate organic carbon (POC) and nitrogen (PN), including ice algae, are supplied from sea ice into the water column. To understand carbon flow through food webs in this productive marginal ice zones, it is necessary to determine the quantity and quality of organic carbon and nitrogen in sea ice. However, knowledge regarding brash sea ice is scarce, even though it is the predominant form at the Antarctic ice edge. In this study, 102 sea-ice samples were collected from the Indian sector (20–160°E) during summer to clarify variations in isotopic baselines and the potential contribution of sea ice-derived carbon and nitrogen to the water column. The δ13C and δ15N values of sea-ice particulate matter were −24.5±3.2‰ and +1.6±2.2‰ (mean±standard deviation), respectively, showing greater variability compared to those in seawater (−28.8±1.0‰ for δ13C and −0.5±1.4‰ for δ15N). We identified correlations of δ13C and δ15N with organic matter and nutrient concentrations and their ratios (e.g., silicate:nitrate), indicating that nutrient consumption and organic matter decomposition influenced those isotopic characteristics in sea ice. Using freshwater flux from sea ice melt and the measured sea-ice POC concentrations, this supply was estimated to be 4.6±0.3 Tg C year−1, equivalent to >14% of primary production in the marginal ice zone of the studied region. These results suggest that the carbon supply from sea ice is a crucial factor supporting ecosystems in the seasonal sea ice zone., 46051628;46051629 - Marine ecosystem monitoring in the sea-ice region of Lützow-Holm Bay, off Syowa Station, during the icebreaker Shirase cruise of the 61st Japanese Antarctic Research Expedition
Kunio T. Takahashi; Ryosuke Makabe; Keigo D. Takahashi; Tsuneo Odate
Polar Data Journal, 10, 1, 13, 20 Jan. 2026, [Peer-reviewed] - Overview of the SLOPE2024 for sea ice biogeochemistry and physics in Saroma-ko Lagoon, Hokkaido, Japan
Daiki Nomura; Ryota Akino; Keiichiro Hara; Naoya Kanna; Kineta Kunimatsu; Takayuki Kuramoto; Rie Kuroi; Yutaka Kurosaki; Norio Kurosawa; Ryosuke Makabe; Sumito Matoba; Ryo Matsuda; Nozomi Mori; Miku Narusawa; Yuichi Nosaka; Masatoshi Numata; Hajime Obata; Fujio Ohnishi; Cody C. Owen; Nana Samori; Masayoshi Sano; Ryota Saito; Yumi Sunakawa; Keigo D. Takahashi; Manami Tozawa; Hiromichi Ueno; Pat Wongpan; Masaki Yoshimura; Liyang Zhan
Bulletin of Glaciological Research, 43, 21, 37, Japanese Society of Snow and Ice, 14 Aug. 2025, [Peer-reviewed], ［Internationally co-authored］
English, Scientific journal, 46051628 - Prey items of two fecal pellet-like Gyrodinium species revealed through microscopic and molecular analyses
Ryo Matsuda; Keigo D. Takahashi; Masayoshi Sano; Ryosuke Makabe; Norio Kurosawa
Polar Biology, 48, 3, Springer Science and Business Media LLC, 12 Jul. 2025, [Peer-reviewed]
English, Scientific journal, 46051628 - Algal enrichment process for newly formed sea ice in the Dalton polynya off East Antarctica during the late summer–early autumn
Keigo D. Takahashi; Masato Ito; Natsumi Nojiro; Daiki Nomura; Masayoshi Sano; Shigeru Aoki; Pat Wongpan; Guy D. Williams; Michiyo Yamamoto-Kawai; Takeshi Tamura; Masato Moteki; Toru Hirawake; Ryosuke Makabe
Elementa: Science of the Anthropocene, 13, 1, University of California Press, 02 Jun. 2025, [Peer-reviewed], [Lead author, Corresponding author], ［Internationally co-authored］
English, Scientific journal, 46051628;46051629 - Intense frazil ice production promotes high algal biomass in newly-formed sea ice
Masato Ito; Keigo D. Takahashi; Ryosuke Makabe; Daisuke Hirano; Kay I. Ohshima; Takeshi Tamura; Shigeru Aoki
Journal of Geophysical Research: Oceans, 130, 3, e2024JC021689, American Geophysical Union (AGU), 01 Mar. 2025, [Peer-reviewed]
English, Scientific journal, 46051629 - Spatial and temporal occurrence of two Gyrodinium species in the seasonal ice zone off Wilkes Land, Southern Ocean
Ryo Matsuda; Masayoshi Sano; Chiho Tsuchiya; Keigo D. Takahashi; Shintaro Takao; Kohei Mizobata; Masato Moteki; Ryosuke Makabe; Norio Kurosawa
Polar Science, 43, 101169, Elsevier BV, 30 Jan. 2025, [Peer-reviewed]
English, Scientific journal - Different vertical distribution of diatoms in sea ice at the river mouth and off the eastern coast of Saroma-ko Lagoon, Hokkaido, Japan
Keigo D. Takahashi; Daiki Nomura; Yuichi Nosaka
Laguna, 31, 15, 24, Japanese Association for Estuarine Science, 31 Dec. 2024, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal, 46051628 - Multidisciplinary research for sea ice in Saroma-ko Lagoon, Hokkaido, Japan 2023
Daiki Nomura; Ryota Akino; Matthew Corkill; Keizo Hirano; Akihide Kasai; Seiji Katakura; Yusuke Kawaguchi; Tatsuya Kawakami; Riri Kimura; Delphine Lannuzel; Ryosuke Makabe; Mirai Matsuura; Kohei Matsuno; Klaus Meiners; Keizo Nagasaki; Yuichi Nosaka; Nana Samori; Shinnosuke Sakaya; Eun Yae Son; Ryotaro Suga; Yumi Sunakawa; Keigo D. Takahashi; Masaharu Takahashi; Yuka Takeda; Takenobu Toyota; Manami Tozawa; Pat Wongpan; Hiroshi Yoshida; Kazuhiro Yoshida; Masaki Yoshimura
Bulletin of Glaciological Research, 42, 19, 37, Japanese Society of Snow and Ice, 13 Jun. 2024, [Peer-reviewed]
English, Scientific journal, 46051628 - Summer ice-algal blooms by the diatom Fragilariopsis curta (Van Heurck) Hustedt off Cape Darnley, Southern Ocean
Keigo D. Takahashi; Masato Ito; Masayoshi Sano; Ryosuke Makabe; Michiyo Yamamoto-Kawai; Kay I. Ohshima
Diatom, 39, 12, 20, 11 Oct. 2023, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal, 43288461 - Application of the filter-transfer-freeze technique to permanent slide preparation
Keigo D. Takahashi; Ryosuke Makabe
Diatom, 39, 21, 24, 11 Oct. 2023, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal, 43288461 - Interannual and spatial variation in small zooplankton off Vincennes Bay, East Antarctica
Aiko Tachibana; Yuri Ohkubo; Kohei Matsuno; Keigo D. Takahashi; Ryosuke Makabe; Masato Moteki
Polar Biology, 46, 915, 932, Springer Science and Business Media LLC, 18 Jul. 2023, [Peer-reviewed]
English, Scientific journal - Biogeochemical characteristics of brash sea ice and icebergs during summer and autumn in the Indian sector of the Southern Ocean
Daiki Nomura; Reishi Sahashi; Keigo D. Takahashi; Ryosuke Makabe; Masato Ito; Manami Tozawa; Pat Wongpan; Ryo Matsuda; Masayoshi Sano; Michiyo Yamamoto-Kawai; Natsumi Nojiro; Aiko Tachibana; Norio Kurosawa; Masato Moteki; Takeshi Tamura; Shigeru Aoki; Hiroto Murase
Progress in Oceanography, 214, 103023, Elsevier BV, 14 Apr. 2023, [Peer-reviewed]
English, Scientific journal, 43288461 - Impacts of basal melting of the Totten Ice Shelf and biological productivity on marine biogeochemical components in Sabrina Coast, East Antarctica
Tetsuya P. Tamura; Daiki Nomura; Daisuke Hirano; Takeshi Tamura; Masaaki Kiuchi; Gen Hashida; Ryosuke Makabe; Kazuya Ono; Shuki Ushio; Kaihe Yamazaki; Yoshihiro Nakayama; Keigo D. Takahashi; Hiroko Sasaki; Hiroto Murase; Shigeru Aoki
Global Biogeochemical Cycles, 37, e2022GB007510, American Geophysical Union (AGU), 13 Sep. 2022, [Peer-reviewed]
English, Scientific journal - Phytoplankton and ice-algal communities in the seasonal ice zone during January (Southern Ocean, Indian sector)
Keigo D. Takahashi; Ryosuke Makabe; Shintaro Takao; Haruhiko Kashiwase; Masato Moteki
Journal of Oceanography, 78, 5, 409, 424, Springer Science and Business Media LLC, 25 Jun. 2022, [Peer-reviewed], [Lead author, Corresponding author]
English, Scientific journal, 43288461 - North-south changes of zooplankton community and copepods population along the 110°E line in the Indian sector of the Southern Ocean during the austral summer
Rikuto Sugioka; Kohei Matsuno; Keigo D. Takahashi; Ryosuke Makabe; Masato Moteki; Tsuneo Odate; Atsushi Yamaguchi
Bulletin of Fisheries Sciences, 71, 1, 39, 50, 03 Aug. 2021
English, Research institution - Plankton sampling by the training vessel Umitaka-maru in the Indian sector of the Southern Ocean in the austral summer of 2019
Hisae Sakurai; Masato Moteki; Keishi Shimada; Aki Nosaka; Ayu Yamamoto; Junji Matsushita; Keigo Takahashi; Takumi Hasegawa; Satoshi Nirazuka; Aiko Tachibana; Maki Kobayashi; Ayuko Kagesawa; Masayoshi Ssano; Kunio T. Takahashi; Ryosuke Makabe; Tsuneo Odate
JARE Data Reports (Marine Biology), 66, 1, 9, 23 Oct. 2019
English, Research institution - For better understanding of the Southern Ocean history using fossil diatoms and chrysophytes
Itsuki Suto; Yuji Kato; Saki Ishino; Keiji Hattori; Keigo Takahashi; Ryosuke Makabe
Low Temperature Science, 76, 95, 119, 31 Mar. 2018
Japanese, Research institution
- Sea-ice ecosystems and material cycling
Ryosuke Makabe; Keigo D. Takahashi; Masayoshi Sano; Ryo Matsuda; Masato Ito; Shintaro Takao; Aiko Tachibana; Haruhiko Kashiwase; Michiyo Yamamoto-Kawai; Norio Kurosawa; Daiki Nomura; Masato Moteki, Grant-in-Aid for Scientific Research on Innovative Areas "Giant Reservoirs - Antarctic" Research report, 94, 99, 17 Mar. 2023
Japanese, 43288461 - Sea ice observation aboard the icebreaker Shirase
Keigo Takahashi, The Geological Society of Japan News, 24, 7, 29, 30, 15 Jul. 2021, [Lead author]
Japanese, Introduction commerce magazine
- Relationships between the microbial communities and the physicochemical environment of brash sea ice in the marginal ice zone of the Southern Ocean during summer
Maiko I. Takahashi; Daiki Nomura; Masayoshi Sano; Urara Fukuda; Miku Narusawa; Ryo Matsuda; Norio Kurosawa; Keishi Shimada; Yuichi Nosaka; Ryosuke Makabe; Kohei Mizobata; Keigo D. Takahashi
The 2026 Autumn Meeting of the Oceanographic Society of Japan, 10 Sep. 2026, Oral presentation
07 Sep. 2026 - 11 Sep. 2026, Tokyo University of Marine Science and Technology, Japan, 49236066 - An unknown player in carbon ballasting in polar oceans? On board with spectral imaging techniques for sea ice cryogenic mineral detection
Emiliano Cimoli; Daiki Nomura; Keigo D. Takahashi; Jutta Wollenburg; Takenobu Toyota; Dmitry Divine; Morten Iversen; Vanessa Lucieer; Marcel Nicolaus
Australian Antarctic Research Conference, 26 Aug. 2026, English, Oral presentation
25 Aug. 2026 - 28 Aug. 2026, Stanley Burbury Theatre, Australia - Size distribution of particulate matter inside sea ice in Lützow-Holm Bay
Masato Ito; Takeshi Tamura; Keigo D. Takahashi; Atsushi Yoshida; Kazutaka Tateyama; Takuhei Shiozaki; Takuya Sato; Shigeru Aoki; Kay I. Ohshima; Sumito Matoba; Satoshi Imura; Yutaka W. Watanabe; Shuki Ushio; Hiroto Kajita; Ryo Matsuda; Ryosuke Makabe; Kohei Mizobata
The 40th International Symposium on the Okhotsk Sea & Polar Oceans, 16 Feb. 2026, Oral presentation
15 Feb. 2026 - 18 Feb. 2026, Monbetsu Arts & Culture Center, Japan - Particle distribution in the old sediment-laden sea ice in the Arctic Ocean
Keigo D. Takahashi; Emiliano Cimoli; Dmitry Divine; Sarah Lena Eggers; Thomas Krumpen; Morten Iversen; Julia Pamphile dos Santos; Daiki Nomura; Marcel Nicolaus
The 16th Symposium on Polar Science, 04 Dec. 2025, English, Oral presentation
02 Dec. 2025 - 05 Dec. 2025, National Institute of Polar Research, Japan, 46051628 - 南大洋の多様な植物プランクトンと凝集体形成の関係
Keigo D. Takahashi
The 2025 CREST Meeting, 25 Nov. 2025, Japanese, Poster presentation
25 Nov. 2025 - 27 Nov. 2025, TOKI MESSE: Niigata Convention Center, Japan, 46051628;49104644 - Distribution and export flux of transparent exopolymer particles in fast ice area
Keigo D. Takahashi; Daiki Nomura; Ryota Akino; Masaki Yoshimura; Amane Fujiwara; Hisatomo Waga; Masayoshi Sano; Yuichi Nosaka
The 8th International Symposium on Arctic Research, 30 Oct. 2025, English, Poster presentation
28 Oct. 2025 - 31 Oct. 2025, Tokyo Metropolitan Tama Business Activation Center, Japan, 46051628 - The biogeochemical characteristics of sediment-laden ice along the coast of Alaska: Potential impact of sediment loads on nutrients
Ryota Akino; Daiki Nomura; Masaki Yoshimura; Keigo D. Takahashi; Amane Fujiwara; Mariko Hatta; Hisatomo Waga; Laura Whitmore
The 8th International Symposium on Arctic Research, 29 Oct. 2025, English, Poster presentation
28 Oct. 2025 - 31 Oct. 2025, Tokyo Metropolitan Tama Business Activation Center, Japan - Exploring hyperspectral imaging techniques to elucidate cryogenic mineral formation and function in Arctic sea ice
Emiliano Cimoli; Daiki Nomura; Keigo D. Takahashi; Jutta Wollenburg; Ilka Peeken; Marcel Nicolaus; Vanessa Lucieer; Morten Iversen
The 8th International Symposium on Arctic Research, 29 Oct. 2025, English, Poster presentation
28 Oct. 2025 - 31 Oct. 2025, Tokyo Metropolitan Tama Business Activation Center, Japan - Emerging hyperspectral imaging applications for sea-ice biogeochemical research
Emiliano Cimoli; Benjamin Lange; Vanessa Lucieer; Daiki Nomura; Klaus Meiners; Janina Osanen; Keigo D. Takahashi; Florian Zimmer; Marcel Nicolaus; Jutta Wollenburg; Mats Granskog
The 8th International Symposium on Arctic Research, 29 Oct. 2025, English, Invited oral presentation
28 Oct. 2025 - 31 Oct. 2025, Tokyo Metropolitan Tama Business Activation Center, Japan, [Invited] - 凍結乾燥法による海氷中のクロロフィルa濃度の評価
Yuichi Nosaka; Daiki Nomura; Keiog D. Takahashi; Ryosuke Makabe; Iroha Ueda; Hideki Minami
The 2025 Autumn Meeting of the Oceanographic Society of Japan, 24 Sep. 2025, Japanese, Oral presentation
21 Sep. 2025 - 25 Sep. 2025, Hokkaido University Hakodate Campus, Japan - Effect of sediment loads on the biogeochemical properties of sea ice along the coast of Alaska, Arctic Ocean
Ryota Akino; Daiki Nomura; Masaki Yoshimura; Keigo D. Takahashi; Amane Fujiwara; Mariko Hatta; Hisatomo Waga; Laura Whitmore
Japan Geoscience Union Meeting 2025, 29 May 2025, Japanese, Oral presentation
25 May 2025 - 30 May 2025, Makuhari Messe, Japan - 海洋植物プランクトンの暗所における栄養塩消費と生存戦略
Mikan Toishita; Yuichi Nosaka; Keigo D. Takahashi; Yokyo Ri; Atsushi Ooki
海洋生物シンポジウム2025, 17 Mar. 2025, Japanese, Oral presentation
17 Mar. 2025 - 17 Mar. 2025, Tokyo University of Marine Science and Technology, Japan - Spatial distribution and genetic diversity of ice-associated copepods in the Southern Ocean
Miku Narusawa; Keigo D. Takahashi; Ryo Matsuda; Masayoshi Sano; Ryosuke Makabe; Masato Moteki; Norio Kurosawa
The 15th Symposium on Polar Science, 03 Dec. 2024, English, Poster presentation
03 Dec. 2024 - 05 Dec. 2024, National Institute of Polar Research, Japan - Distribution of microalgal communities of drift and fast ice in the Indian Sector of the Southern Ocean
Keigo D. Takahashi; Ryo Matsuda; Masayoshi Sano; Daiki Nomura; Natsumi Nojiro; Michiyo Yamamoto-Kawai; Masato Ito; Norio Kurosawa; Masato Moteki; Takeshi Tamura; Toru Hirawake; Ryosuke Makabe
The 45th Japanese Society of Diatomology Meeting, 22 Jun. 2024, Japanese, Oral presentation
22 Jun. 2024 - 23 Jun. 2024, Rakuno Gakuen University, Japan, 46051628;46051629 - Population density and genetic diversity of sea ice-associated copepods in the Indian sector of the Southern Ocean
Miku Narusawa; Keigo D. Takahashi; Ryo Matsuda; Masayoshi Sano; Ryosuke Makabe; Masato Moteki; Norio Kurosawa
The 15th International Conference on Copepoda, 03 Jun. 2024, English, Poster presentation
02 Jun. 2024 - 07 Jun. 2024, International Conference Center Hiroshima, Japan, [International presentation] - The occurrence of Gyrodinium species (Dinophyceae) in the Indian sector of the Southern Ocean
Ryo Matsuda; Keigo D. Takahashi; Masayoshi Sano; Ryosuke Makabe; Shintaro Takao; Masato Moteki; Norio Kurosawa
The 38th International Symposium on the Okhotsk Sea and Polar Oceans, 20 Feb. 2024, Oral presentation
19 Feb. 2024 - 21 Feb. 2024, Monbetsu Arts & Culture Center, Japan - Eukaryotic community structure in sea ice and sinking particles during summer off Wilkes Land, East Antarctica
Ryo Matsuda; Keigo D. Takahashi; Masayoshi Sano; Ryosuke Makabe; Shintaro Takao; Masato Moteki; Norio Kurosawa
The 14th Symposium on Polar Science, 15 Nov. 2023, English, Poster presentation
14 Nov. 2023 - 17 Nov. 2023, National Institute of Polar Research, Japan - Population density and genetic diversity of sympagic copepods in the Southern Ocean
Miku Narusawa; Keigo D. Takahashi; Ryo Matsuda; Masayoshi Sano; Ryosuke Makabe; Masato Moteki; Norio Kurosawa
The 14th Symposium on Polar Science, 15 Nov. 2023, English, Poster presentation
14 Nov. 2023 - 17 Nov. 2023, National Institute of Polar Research, Japan - Prokaryotic and eukaryotic community structures in surface sediments of the East Antractic coastal region
Hideaki Ochi; Ryo Matsuda; Keigo D. Takahashi; Ryosuke Makabe; Takuya Itaki; Shin Sugiyama; Norio Kurosawa
The 14th Symposium on Polar Science, 15 Nov. 2023, English, Poster presentation
14 Nov. 2023 - 17 Nov. 2023, National Institute of Polar Research, Japan - Viability and seeding potential of large diatoms inhabiting Antarctic drift ice
Keigo D. Takahashi; Chiho Tsuchiya; Shintaro Takao; Masayoshi Sano; Ryosuke Makabe; Masato Moteki
The 2023 Autumn Meeting of the Oceanographic Society of Japan, 27 Sep. 2023, Japanese, Oral presentation
25 Sep. 2023 - 27 Sep. 2023, Kyoto University Yoshida Campus, Japan, 43288461 - 南大洋インド洋区の季節海氷域における原生生物沈降フラックスの季節変化
Chiho Tsuchiya; Keigo D. Takahashi; Ryo Matsuda; Masayoshi Sano; Shintaro Takao; Ryosuke Makabe; Norio Kurosawa; Masato Moteki
The 2023 Autumn Meeting of the Oceanographic Society of Japan, 25 Sep. 2023, Japanese, Poster presentation
25 Sep. 2023 - 27 Sep. 2023, Kyoto University Yoshida Campus, Japan - 南大洋に生息するGyrodinium属渦鞭毛虫の定量的評価： 形態観察と分子生物学的手法によるアプローチ
Ryo Matsuda; Keigo D. Takahashi; Chiho Tsuchiya; Masayoshi Sano; Ryosuke Makabe; Shintaro Takao; Norio Kurosawa; Masato Moteki
The 2023 Autumn Meeting of the Oceanographic Society of Japan, 25 Sep. 2023, Japanese, Oral presentation
25 Sep. 2023 - 27 Sep. 2023, Kyoto University Yoshida Campus, Japan - Analysis of population density and genetic diversity of copepods inhabiting drift ice in the Southern Ocean
Miku Narusawa; Keigo D. Takahashi; Ryo Matsuda; Masayoshi Sano; Ryosuke Makabe; Masato Moteki; Norio Kurosawa
Extremophiles, 28 Aug. 2023, Japanese, Poster presentation
28 Aug. 2023 - 29 Aug. 2023, Kitami Institute of Technology, Japan - Contrasting phytoplankton communities between Cape Darnley and Dalton Polynyas, off East Antarctica, during sea-ice melting and forming seasons
Keigo D. Takahashi; Ryosuke Makabe; Michiyo Yamamoto-Kawai; Takeshi Tamura; Masato Moteki
Southern Ocean Observing System (SOOS) Symposium, 17 Aug. 2023, English, Oral presentation
14 Aug. 2023 - 18 Aug. 2023, Hotel Grand Chancellor Hobart, Australia, 43288461 - Use of a drifter array for observing temporal variability of pelagic ecosystems and material cycling in seasonal ice zone
Ryosuke Makabe; Keigo D. Takahashi; Chiho Tsuchiya; Masayoshi Sano; Masato Ito; Ryo Matsuda; Shintaro Takao; Norio Kurosawa; Masato Moteki
Southern Ocean Observing System (SOOS) Symposium, 15 Aug. 2023, English, Poster presentation
14 Aug. 2023 - 18 Aug. 2023, Hotel Grand Chancellor Hobart, Australia - Diversity and communities of eukaryotic organisms in sea ice revealed by high through-put DNA sequencing (Southern Ocean, Indian sector)
Ryo Matsuda; Keigo D. Takahashi; Masayoshi Sano; Ryosuke Makabe; Shintaro Takao; Masato Moteki; Norio Kurosawa
Southern Ocean Observing System (SOOS) Symposium, 15 Aug. 2023, English, Poster presentation
14 Aug. 2023 - 18 Aug. 2023, Hotel Grand Chancellor Hobart, Australia - Particulate organic matters in sea ice floe in the Indian sector of the Southern Ocean
Ryosuke Makabe; Masayoshi Sano; Keigo D. Takahashi; Shintaro Takao; Ryo Matsuda; Masato Ito; Michiyo Yamamoto-Kawai; Daiki Nomura; Norio Kurosawa; Masato Moteki
The 13th Symposium on Polar Science, 16 Nov. 2022, English, Poster presentation
15 Nov. 2022 - 18 Nov. 2022, Online, Japan - The occurrence of a dinoflagellate species Gyrodinium rubrum in sea ice in the Indian sector of the Southern Ocean
Ryo Matsuda; Masayoshi Sano; Keigo D. Takahashi; Shintaro Takao; Ryosuke Makabe; Michiyo Yamamoto-Kawai; Masato Moteki; Norio Kurosawa
The 13th Symposium on Polar Science, 16 Nov. 2022, English, Poster presentation
15 Nov. 2022 - 18 Nov. 2022, Online, Japan - Temporal changes in protist fluxes during sea ice melt off Wilkes land, East Antarctica
Chiho Tsuchiya; Keigo D. Takahashi; Masayoshi Sano; Ryosuke Makabe; Shintaro Takao; Masato Moteki
The 13th Symposium on Polar Science, 16 Nov. 2022, English, Poster presentation
15 Nov. 2022 - 18 Nov. 2022, Online, Japan - Incorporation of phytoplankton into newly-formed sea ice in Dalton Polynya and off Totten Ice Shelf (Southern Ocean) during late summer
Keigo D. Takahashi; Masato Ito; Natsumi Nojiro; Daiki Nomura; Pat Wongpan; Masayoshi Sano; Guy D. Williams; Ryosuke Makabe; Michiyo Yamamoto-Kawai; Takeshi Tamura; Shigeru Aoki; Masato Moteki
The 10th SCAR Open Science Conference, 07 Aug. 2022, English, Oral presentation
01 Aug. 2022 - 10 Aug. 2022, Online, 43288461 - Summer ice-algal blooms by the diatom Fragilariopsis curta off Cape Darnley, Southern Ocean
Keigo D. Takahashi; Masato Ito; Ryosuke Makabe; Masayoshi Sano; Kay I. Ohshima
The 43th Japanese Society of Diatomology Meeting, 04 Jun. 2022, Oral presentation
04 Jun. 2022 - 04 Jun. 2022, Online, Japan, 43288461 - Zooplankton vertical distribution during sea ice melting season in the Southern Ocean
Ryosuke Makabe; Masato Ito; Chiho Tsuchiya; Keigo D. Takahashi; Keishi Shimada; Shintaro Takao; Masayoshi Sano; Kohei Mizobata; Norio Kurosawa; Masato Moteki
Japan Geoscience Union Meeting 2022, 22 May 2022, English, Oral presentation
22 May 2022 - 03 Jun. 2022, Online, Japan - Silica concentrations of seawater and sea-ice in the coastal regions of the Southern Ocean
Natsumi Nojiro; Michiyo Yamamoto-Kawai; Ryosuke Makabe; Keigo D. Takahashi
The 12th Symposium on Polar Science, 17 Nov. 2021, English, Poster presentation
15 Nov. 2021 - 17 Nov. 2021, Online, Japan - Observation of pelagic system using a drifter off Wilkes land during sea ice melting season
Ryosuke Makabe; Keigo D. Takahashi; Masayoshi Sano; Masato Ito; Ryo Matsuda; Norio Kurosawa; Masato Moteki; Tsuneo Odate
Japan Geoscience Union Meeting 2021, 06 Jun. 2021, English, Oral presentation
30 May 2021 - 06 Jun. 2021, Online, Japan, [International presentation] - Seasonal variation in physical and biological parameters during sea ice melting season in the Southern Ocean
Ryosuke Makabe; Keigo D. Takahashi; Shintaro Takao; Ryo Matsuda; Kohei Mizobata; Norio Kurosawa; Masato Moteki; Tsuneo Odate
The 11th Symposium on Polar Science, 02 Dec. 2020, English, Poster presentation
01 Dec. 2020 - 03 Dec. 2020, Online, Japan - Algal concentration and composition in newly formed/young sea ice in Antarctic
Keigo D. Takahashi; Masato Ito; Ryosuke Makabe; Takeshi Tamura; Tsuneo Odate; Masato Moteki
The 11th Symposium on Polar Science, 02 Dec. 2020, English, Oral presentation
01 Dec. 2020 - 03 Dec. 2020, Online, Japan - 南極・ケープダンレーポリニヤ域における植物プランクトンの秋季大増殖を伴う新成氷生成
Masato Ito; Daisuke Hirano; Ryosuke Makabe; Keigo Takahashi; Kay I. Ohshima; Shigeru Aoki
The 2019 Autumn Meeting of the Oceanographic Society of Japan, 28 Sep. 2019, Japanese, Oral presentation
25 Sep. 2019 - 29 Sep. 2019, Toyama International Conference Center, Japan - Preliminary report of experiment on effect of low salinity ice melting water on biomass and composition of ice algae
Keigo Takahashi; Ryosuke Makabe; Shintaro Takao; Tsuneo Odate; Masato Moteki
Japan Geoscience Union Meeting 2019, 27 May 2019, English, Poster presentation
26 May 2019 - 30 May 2019, Makuhari Messe, Japan - Ice-algal communities in the Antarctic coastal regions during sea-ice forming season
Keigo D. Takahashi; Masato Ito; Ryosuke Makabe; Tsuneo Odate; Masato Moteki
The 40th Japanese Society of Diatomology Meeting, 11 May 2019, Japanese, Poster presentation
11 May 2019 - 12 May 2019, OTEPIA Kochi Library, Japan - For better understanding of the Southern Ocean history
Itsuki Suto; Yuji Kato; Saki Ishino; Keiji Hattori; Keigo Takahashi; Ryosuke Makabe
Japan Geoscience Union Meeting 2018, 21 May 2018, English, Oral presentation
20 May 2018 - 24 May 2018, Makuhari Messe, Japan - Diversity and community structure of protist in the floating sea ice of Southern Ocean revealed by 18S rDNA amplicon sequencing
Norio Kurosawa; Eiji Nakamura; Keigo Takahashi; Ryosuke Makabe; Shitaro Takao; Tsuneo Odate; Masato Moteki
Marine Ecosystem Assessment of the Southern Ocean (MEASO2018), 12 Apr. 2018, English, Poster presentation
09 Apr. 2018 - 13 Apr. 2018, C3 Convention Centre, Australia - Increased ice algae in the water column after melting of sea ice off Vincennes Bay, East Antarctica, during the austral summer
Keigo Takahashi; Ryosuke Makabe; Shintaro Takao; Naho Miyazaki; Masato Moteki; Tsuneo Odate
Marine Ecosystem Assessment of the Southern Ocean (MEASO2018), 12 Apr. 2018, English, Oral presentation
09 Apr. 2018 - 13 Apr. 2018, C3 Convention Centre, Australia, 43288537 - Release of microalgae from annual sea ice into the water column during the austral summer off Vincennes Bay (Indian sector, Southern Ocean)
Keigo Takahashi; Ryosuke Makabe; Shintaro Takao; Naho Miyazaki; Masato Moteki; Tsuneo Odate
The 8th Symposium on Polar Science, 05 Dec. 2017, English, Oral presentation
04 Dec. 2017 - 08 Dec. 2017, National Institute of Polar Research, Japan - Release of microalgae from seasonal sea ice into the water column in the Antarctic Ocean during summer
Keigo Takahashi; Ryosuke Makabe; Shintaro Takao; Naho Miyazaki; Masato Moteki; Tsuneo Odate
The 2017 Autumn Meeting of the Oceanographic Society of Japan, 15 Oct. 2017, Japanese, Oral presentation
13 Oct. 2017 - 17 Oct. 2017, Sendai International Center, Japan
- Understanding the effects of pytoplankton composition on the biological carbon pump focusing on the formation and sinking of aggregates
Grants-in-Aid for Scientific Research
Apr. 2026 - Mar. 2029
Keigo D. Takahashi
Japan Society for the Promotion of Science, Grant-in-Aid for Early-Career Scientists, Hokkaido University, Principal investigator, 26K21416 - Assessing the impact of sediments from sea ice on the ocean based on comparisons of different sediment-laden sea ice
Special Collaboration Project
Apr. 2026 - Mar. 2027
Keigo D. Takahashi; Hisatomo Waga; Laura Whitmore; Thomas Krumpen; Morten Iversen; Daiki Nomura; Ryota Akino; Maiko I. Takahashi
National Institute of Polar Research, Principal investigator, ［Internationally co-authored］, N26-01 - Roles of algal aggregates on the biological pump in the sea ice zone
Grants-in-Aid for Scientific Research
Apr. 2024 - Mar. 2027
Keigo D. Takahashi
Japan Society for the Promotion of Science, Grant-in-Aid for JSPS Fellows, Hokkaido University, Principal investigator, 24KJ0006 - Estimating the sources of ammonia and oxidized nitrogen in Antarctic sea ice
General Collaboration Project
Apr. 2025 - Mar. 2026
Keigo D. Takahashi; Daiki Nomura; Norio Kurosawa
National Institute of Polar Research, Principal investigator, G7-06 - Young Researcher Challenge X
Apr. 2025 - Mar. 2026
Keigo D. Takahashi
Japan Science and Technology Agency, Principal investigator - Understanding the mechanisms of algal bloom formation in newly-formed sea ice using ice tanks
Grants-in-Aid for Scientific Research
Apr. 2024 - Mar. 2026
Keigo D. Takahashi
Japan Society for the Promotion of Science, Grant-in-Aid for Early-Career Scientists, Hokkaido University, Principal investigator, 24K17997 - Does the viability of algae released from sea ice explain the spatio-temporal heterogeneity of ice-edge bloom?
Grants-in-Aid for Scientific Research
Apr. 2021 - Mar. 2024
Keigo D. Takahashi
Japan Society for the Promotion of Science, Grant-in-Aid for JSPS Fellows, The Graduate University for Advanced Studies, Principal investigator, 21J14914 - Travel expenses for attending international meeting, by Grant-in-Aid for Scientific Research on Innovative Areas
Apr. 2018 - Apr. 2018
Keigo D. Takahashi
Principal investigator
Industrial Property Rights
- Interdisciplinary research on marine environmental variations in polar and cold regions
21 Sep. 2025 - 25 Sep. 2025
Panel chair etc
Academic society etc - The 2025 Autumn Meeting of the Oceanographic Society of Japan
21 Sep. 2025 - 25 Sep. 2025
Planning etc
Academic society etc - Elementa: Science of the Anthropocene
Peer review - Journal of Oceanography
Peer review - Marine Environmental Research
Peer review - Polar Biology
Peer review - Limnology and Oceanography
Peer review - Frontiers in Marine Science
Peer review - Polar Science
Peer review - Ocean-Land-Atmosphere Research
Peer review
- Hokkaido University explores hyperspectral imaging to reveal hidden minerals in sea ice
11 Nov. 2025
Specim
[Internet]
- May 2026 - Jun. 2026
Utqiaġvik Sea Ice Research - Feb. 2026 - Apr. 2026
The 67th Japanese Antarctic Research Expedition - Jul. 2025 - Sep. 2025
CONTRASTS (PS149) - Jan. 2025 - Feb. 2025
Saroma-ko Lagoon Sea Ice Research - May 2024
Utqiaġvik Sea Ice Research - Feb. 2024
Saroma-ko Lagoon Sea Ice Research - Feb. 2023 - Mar. 2023
Saroma-ko Lagoon Sea Ice Research - Dec. 2019 - Mar. 2020
The 61st Japanese Antarctic Research Expedition - Dec. 2018 - Jan. 2019
The 60th Japanese Antarctic Research Expedition - Dec. 2017 - Jan. 2018
The 59th Japanese Antarctic Research Expedition
