Details of the Researcher

PHOTO

Kota Ishikawa
Section
Graduate School of Life Sciences
Job title
Assistant Professor
Degree

  • PhD (Okinawa Institute of Science and Technology Graduate University)

  • BS (Waseda University)

Research History 9

  • 2025/05 - Present
    Tohoku U & JAMSTEC Advanced Institute for Marine Ecosystem Change (WPI-AIMEC)

  • 2025/05 - Present
    Tohoku University　Graduate School of Life Sciences　Assistant professor

  • 2024/08 - 2025/04
    Tohoku University & JAMSTEC Advanced Institute for Marine Ecosystem Change (WPI-AIMEC)　Postdoc Researcher

  • 2024/04 - 2024/07
    University of the Ryukyus　Postdoc Researcher

  • 2024/03 - 2024/03
    Okinawa Institute of Science and Technology Graduate University　Junior Research Fellow

  • 2024/03 - 2024/03
    Japan Society for the Promotion of Science　Research Fellow PD

  • 2023/04 - 2024/02
    Japan Society for the Promotion of Science　Research Fellow DC2

  • 2019/09 - 2024/02
    Okinawa Institute of Science and Technology Graduate University　PhD student

  • 2019/04 - 2019/08
    Waseda University

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Education 2

  • Okinawa Institute of Science and Technology Graduate University　PhD

    2019/09 - 2024/02

  • Waseda University　School of Education　Biology

    2015/04 - 2019/03

Research Interests 5

  • ecology

  • turbulence

  • coral reef fish

  • fluid dynamics

  • animal behavior

Research Areas 5

  • Natural sciences / Atmospheric and hydrospheric science /

  • Life sciences / Ecology and environmental science /

  • Life sciences / Animals: biochemistry, physiology, behavioral science /

  • Life sciences / Marine/Aquatic life sciences /

  • Environmental science/Agricultural science / Environmental dynamics /

Awards 3

  1. Research Encouragement Award, Graduate School of Life Sciences

    2025/12　Tohoku University

  2. Trish Morse Endowed Scholarship for Japan / U.S. Exchange

    2018/07

  3. 佐藤奨学会奨学金

    2016/04

Papers 8

  1. Automated high-frequency quantification of fish communities and biomass using computer vision

    Kota Ishikawa, Takuma Masui, Keita Koeda, Rickdane Gomez, Lucas Yutaka Kimura, Michio Kondoh

    arXiv　2026/05/11

    More details Close

    Quantifying fish community structure is essential for understanding biodiversity and ecosystem responses in a changing environment, yet existing survey methods provide limited high-frequency, quantitative observations. Conventional approaches, including catch-based methods, underwater visual censuses, and environmental DNA metabarcoding, either require intensive labor or lack reliable estimates of abundance and biomass. Here, we develop an automated framework for quantifying fish communities from underwater video using computer vision. Using videos acquired with a custom-made stereo camera system, the framework integrates deep learning-based fish identification, multi-object tracking, and 3D reconstruction to estimate species-level abundance and biomass. We applied the approach to a reef fish community over a 20-day period with hourly daytime observations, revealing dynamic fluctuations in species richness, abundance, and biomass associated with changes in species composition. By comparing fish communities estimated from visual census and environmental DNA surveys, we demonstrate that our method provides complementary strengths for continuous, non-invasive, and quantitative monitoring of consistently observed species. This approach provides a scalable foundation for long-term monitoring and advances the capacity to resolve fine-scale temporal dynamics in fish communities.

  2. Energy costs and benefits of locomotion and feeding in site-attached damselfish Peer-reviewed

    Kota Ishikawa, Heng Wu, Satoshi Mitarai, Amatzia Genin

    Journal of Experimental Biology　228　(19)　2025/10/06

    DOI： 10.1242/jeb.251164 　

  3. Turbulence effects on free and anchored zooplanktivorous fish in coral reefs Peer-reviewed

    Kota Ishikawa, Heng Wu, Satoshi Mitarai, Amatzia Genin

    Coral Reefs　44　1079-1091　2025/05/20

    DOI： 10.1007/s00338-025-02673-2 　

  4. Use of videos to measure dynamic body acceleration as a proxy for metabolic costs of coral-reef damselfish (Chromis viridis) Peer-reviewed

    Kota Ishikawa, Heng Wu, Satoshi Mitarai, Amatzia Genin

    Journal of Experimental Biology　228　(7)　2025/04/03

    DOI： 10.1242/jeb.249717 　

  5. Effects of flows on transparent exopolymer particles released from branching Acropora coral colonies Peer-reviewed

    Heng Wu, Yosuke Yamada, Po-Shun Chuang, Kota Ishikawa, Satoshi Mitarai

    Frontiers in Marine Science　11　2024/06/24

    Publisher: Frontiers Media SA

    DOI： 10.3389/fmars.2024.1404526 　

    eISSN： 2296-7745

    More details Close

    Transparent exopolymer particles (TEP), a major component of coral mucus, are responsible for particle aggregation. These particles contribute substantially to the carbon cycle in coral reefs, and serve as an energy source for bacteria and other microorganisms. Water flows and induced turbulent mixing control material exchange between the coral canopy and the surrounding water, which is critical for coral health. However, how these factors affect TEP release by coral colonies has yet to be evaluated. Using a recirculating flume, we assessed TEP release by branching Acropora coral colonies and associated bacterial growth in the water column under different unidirectional flows. Changes in TEP and bacterial concentrations after 24-h incubation were quantified for flow speeds of 0, 5, 10, and 30 cm/s. Particle image velocimetry (PIV) measurements provided an estimate of turbulent mixing efficiency above the coral canopy. TEP and bacterial concentrations in the water column increased after 24 h of incubation. The increase in TEP and bacterial concentrations were 6.2–9.3 times and 3.4–5.1 times higher in the absence of flows, respectively, than mean values under water flows. Although mixing efficiency increased linearly with mean flow speeds, TEP release and bacterial growth differed only marginally at flows ranging from 5–30 cm/s. Detailed flow measurements combined with evaluation of TEP release suggest that the complex geometry of corals facilitates efficient material exchange at a range of flow speeds, and highlight the importance of considering these factors when estimating coral reef biogeochemistry.

  6. Canonical and Non-Canonical Functions of Erythropoietin and Its Receptor in Mature Nucleated Erythrocytes of Western Clawed Frog, Xenopus tropicalis Peer-reviewed

    Kazuki Omata, Makoto Kashima, Makiko Ohkido-Yamamoto, Noriyuki Murai, Kota Ishikawa, Hiromi Hirata, Takashi Kato

    Zoological Science　41　(4)　2024/05/22

    Publisher: Zoological Society of Japan

    DOI： 10.2108/zs240004 　

    ISSN： 0289-0003

  7. Effects of prey density and flow speed on plankton feeding by garden eels: a flume study Peer-reviewed

    Kota Ishikawa, Heng Wu, Satoshi Mitarai, Amatzia Genin

    Journal of Experimental Biology　225　(8)　2022/04/15

    Publisher: The Company of Biologists

    DOI： 10.1242/jeb.243655 　

  8. Morphological and Genetic Recovery of Coral Polyps After Bail-Out Peer-reviewed

    Po-Shun Chuang, Kota Ishikawa, Satoshi Mitarai

    Frontiers in Marine Science　8　2021/03

    DOI： 10.3389/fmars.2021.609287 　

    eISSN： 2296-7745

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Presentations 15

  1. 画像解析による魚類群集の高頻度観測

    石川 昂汰, 桝井 拓馬, 小枝 圭太, 近藤 倫生

    第73回 日本生態学会大会　2026/03/12

  2. Time-varying hydrodynamics shape local fish communities in coral reefs

    Kota Ishikawa, Takuma Masui, Keita Koeda, Michio Kondoh

    Ocean Sciences Meeting 2026　2026/02/24

  3. Time-varying hydrodynamics shapes local fish assemblages in coral reefs

    Kota Ishikawa, Takuma Masui, Keita Koeda, Michio Kondoh

    The 28th Japanese Coral Reef Society and 9th Japanese Society for Symbiotic Biology Joint Meeting　2025/11/29

  4. 画像解析による魚類群集推定法の開発：沖縄本島サンゴ礁魚類への応用

    Kota Ishikawa, Takuma Masui, Keita Koeda, Rickdane Gomez, Lucas Yutaka Kimura, Michio Kondoh

    2025年度日本魚類学会年会　2025/11/23

  5. Estimation of fish density and community structure in a coral reef using computer vision

    Kota Ishikawa, Takuma Masui, Keita Koeda, Michio Kondoh

    2025 Joint Conference of the Asian Society of Ichthyologists Annual Meeting and the 12th Indo-Pacific Fish Conference　2025/06/11

  6. Responses of coral reef fish community to flow velocity and turbulence

    Kota Ishikawa, Takuma Masui, Keita Koeda, Michio Kondoh

    Japan Geoscience Union Meeting　2025/05/28

  7. Effects of flows on fish communities in coral reefs

    Kota Ishikawa, Takuma Masui, Keita Koeda, Michio Kondoh

    The 72nd Annual Meeting of the Ecological Society of Japan　2025/03/16

  8. Empirical energy cost and benefit of damselfish, Chromis viridis

    Ishikawa K, Wu H, Mitarai S, Genin A

    Annual meeting of the Ichthyological Society of Japan　2023/09/02

  9. Turbulence effects on zooplanktivory by free-swimming damselfish and anchored garden eels in coral reefs

    Ishikawa K, Wu H, Mitarai S, Genin A

    Japan Geoscience Union Meeting 2023　2023/05/25

  10. Differential responses of swimming reef fish and anchored garden eels to turbulence.

    Ishikawa K, Wu H, Mitarai S, Genin A

    The Society for Integrative and Comparative Biology　2023/01/06

  11. Adaptation of garden eels to flows

    Ishikawa K, Wu H, Mitarai S, Genin A

    The 93rd Annual Meeting of the Zoological Society of Japan　2022/09/08

  12. Effects of flow speed on plankton feeding by garden eels: A flume study

    Ishikawa K, Wu H, Mitarai S, Genin A

    Microscale Ocean Biophysics 6.0.　2022/05/25

  13. Effects of prey density and flow speed on plankton feeding by garden eels: a flume study

    Ishikawa K, Wu H, Mitarai S, Genin A

    Ocean Sciences Meeting 2022　2022/03/03

  14. Effects of flow speed on feeding behavior of garden eels

    Ishikawa K, Wu H, Mitarai S, Genin A

    The 40th Annual Meeting of the Japan Ethological Society　2021/09/22

  15. Effects of flows on fish feeding in coral reefs

    Ishikawa K

    Okinawa Marine Science Workshop 2022　2022/11/25

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Research Projects 4

  1. 渦・蛇行の生態学－海洋構造が駆動する魚類群集の時空間変動－

    近藤 倫生, 安中さやか, 石川昂汰, 桂 将太

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 基盤研究(A)

    Institution: 東北大学

    2026/04 - 2030/03

  2. 珊瑚礁魚類の種構造と相互作用強度に与える流れの影響

    石川 昂汰

    Offer Organization: 日本学術振興会

    System: 科学研究費助成事業

    Category: 若手研究

    Institution: 東北大学

    2025/04/01 - 2027/03/31

  3. Development of quantitative fish community monitoring method using computer vision Competitive

    Kota Ishikawa

    Offer Organization: Ministry of the Environment, Environmental Restoration and Conservation Agency

    System: Environment Research and Technology Development Fund

    Institution: Tohoku University

    2025/04 - 2027/03

  4. Effects of turbulence on feeding behavior and energy cost-benefit of coral reef fish

    Offer Organization: Japan Society for the Promotion of Science

    System: Grants-in-Aid for Scientific Research

    Category: Grant-in-Aid for JSPS Fellows

    Institution: Okinawa Institute of Science and Technology Graduate University

    2023/04 - 2024/03

Teaching Experience 5

  1. 生物学特殊講義A　琉球大学

  2. 生態・進化生物学特選科目Ⅰ　東北大学

  3. 自然科学総合実験　東北大学

  4. Practice in Reading Biological English I　Tohoku University

  5. Special lecture on biology C　University of the Ryukyus

Social Activities 4

  1. [講演] 第25回東北大学出前授業, 仙台青陵中等教育学校

    2025/12 -

  2. [監修] 講談社 さかなクンのギョギョッとサカナスター図鑑４

    2025/11 -

  3. [講演] りっかRIKAサイエンス第42回, ビーガンカフェROTTON

    2025/10 -

  4. [監修] NHK Eテレ ギョギョッとサカナスター チンアナゴ

    2025/07 -