Understanding of fish migration by nitrogen isotope ratio

• Project/Area Number: 19H04247
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 63010:Environmental dynamic analysis-related
• Research Institution: Japan Agency for Marine-Earth Science and Technology
• Principal Investigator: Yoshikawa Chisato 国立研究開発法人海洋研究開発機構, 海洋機能利用部門(生物地球化学センター), 副主任研究員 (40435839)
• Co-Investigator(Kenkyū-buntansha): 伊藤 進一 東京大学, 大気海洋研究所, 教授 (00371790) ; 山口 晴代 国立研究開発法人国立環境研究所, 生物多様性領域, 主任研究員 (20722672) ; 松林 順 国立研究開発法人水産研究・教育機構, 水産資源研究所(横浜), 研究員 (30756052)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Project Status: Completed (Fiscal Year 2022)
• Budget Amount: ¥17,420,000 (Direct Cost: ¥13,400,000、Indirect Cost: ¥4,020,000); Fiscal Year 2022: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000); Fiscal Year 2021: ¥6,240,000 (Direct Cost: ¥4,800,000、Indirect Cost: ¥1,440,000); Fiscal Year 2020: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000); Fiscal Year 2019: ¥5,850,000 (Direct Cost: ¥4,500,000、Indirect Cost: ¥1,350,000)
• Keywords: 窒素同位体比 / 回遊経路 / 海洋生態系モデル / 窒素同位体モデル / 魚類成長ー回遊モデル / 魚類成長-回遊モデル

Outline of Research at the Start

地球温暖化などの気候変動が海洋生物へ与える影響を明らかにするうえで、海洋生物の回遊経路の解明は不可欠である。しかし、海洋生物の中でも特に魚類は、行動範囲が広いため、移動行動の観察は難しく、さまざまな解析手法が試みられているものの、定常的な回遊経路でさえ不明な点がまだ多い。
本研究では、「脊椎骨のアミノ酸窒素同位体比測定」から、対象とする魚が回遊中に食べた餌の窒素同位体比履歴を復元する。「海洋窒素同位体モデル」から再現した窒素同位体比の空間分布と、「魚類成長-回遊モデル」から推定した回遊経路からも、対象とする魚が回遊中に食べた餌の窒素同位体比履歴を推定する。両者の比較から回遊経路を絞り込む。

Outline of Final Research Achievements

Identifying the migration routes of marine animals is crucial for sustainable fisheries management and biodiversity conservation. Although tracking technologies have advanced tremendously, the migration routes over their entire life including the spawning sites or the larva and juvenile habitats are often unknown due to body-size limitations. Here we developed a new method capable of reconstructing the geographic and trophic histories of migratory fish by compound-specific isotope analysis of amino acids in vertebra and eye lens with modeled nitrogen isoscape of phytoplankton.

Academic Significance and Societal Importance of the Research Achievements

本研究では、魚類の脊椎骨や水晶体の窒素同位体比履歴と窒素同位体比の空間分布から、回遊経路を推定する手法を確立した。本手法は、魚類以外のさまざまな海洋生物についても応用可能であることから、気候変動が海洋生物に与える影響の理解や、水産資源の将来予測の精度向上へつながると考えられる。また、本研究でモデルを用いて作成した植物プランクトンの窒素同位体比の空間分布は、観測ベースよりもシームレスかつ高解像度であるため、窒素同位体比を用いて生息環境を復元する研究の精度向上にもつながると考えられる。

Research Products

• [Journal Article] Nitrogen Isotopes of Sinking Particles Reveal the Seasonal Transition of the Nitrogen Source for Phytoplankton (2022)
  • Author(s): Yoshikawa Chisato、Ogawa Nanako O.、Chikaraishi Yoshito、Makabe Akiko、Matsui Yohei、Sasai Yoshikazu、Wakita Masahide、Honda Makio C.、Mino Yoshihisa、Aita Maki N.、Fujiki Tetsuichi、Nunoura Takuro、Harada Naomi、Ohkouchi Naohiko
  • Journal Title: Geophysical Research Letters Volume: 49 Issue: 17
  • DOI: 10.1029/2022gl098670
  • Peer Reviewed / Open Access
• [Journal Article] Compound-Specific Nitrogen Isotope Analysis of Amino Acids in Eye Lenses as a New Tool to Reconstruct the Geographic and Trophic Histories of Fish (2022)
  • Author(s): Harada Y, Ito S, Ogawa NO, Yoshikawa C, Ishikawa NF, Yoneda M and Ohkouchi N
  • Journal Title: Front. Mar. Sci Volume: 8:796532 Pages: 796532-796532
  • DOI: 10.3389/fmars.2021.796532
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Nitrogen sources for phytoplankton in the eastern Indian Ocean determined from δ15N of chlorophyll a and divinylchlorophyll a (2022)
  • Author(s): Y. Isaji, C. Yoshikawa, N. O. Ogawa, K. Matsumoto, A. Makabe, S. Toyoda, N. F. Ishikawa, H. Ogawa, H. Saito, M. C. Honda, N. Ohkouchi
  • Journal Title: Geochemistry, Geophysics, Geosystems Volume: 23 Issue: 4
  • DOI: 10.1029/2021gc010057
  • Peer Reviewed / Open Access
• [Journal Article] Seasonal and Interannual Variations in Nitrogen Availability and Particle Export in the Northwestern North Pacific Subtropical Gyre (2020)
  • Author(s): Mino Y.、Sukigara C.、Honda M. C.、Kawakami H.、Wakita M.、Sasaoka K.、Yoshikawa C.、Abe O.、Kaiser J.、Kimoto K.、Kitamura M.、Fujiki T.、Matsumoto K.、Saino T.
  • Journal Title: Journal of Geophysical Research: Oceans Volume: 125 Issue: 5 Pages: 15600-15600
  • DOI: 10.1029/2019jc015600
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Tracking long-distance migration of marine fishes using compound-specific stable isotope analysis of amino acids (2020)
  • Author(s): Matsubayashi J., Osada Y., Tadokoro K., Abe Y., Yamaguchi A., Shirai K., Honda K., Yoshikawa C., Ogawa N. O., Ohkouchi N., Ishikawa N. F., Nagata T., Miyamoto H., Nishino S., Tayasu I.
  • Journal Title: Ecology Letters Volume: なし Issue: 5 Pages: 881-890
  • DOI: 10.1111/ele.13496
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] Building a nitrogen isoscape of phytoplankton in the western North Pacific using a marine nitrogen isotope model (2022)
  • Author(s): Chisato Yoshikawa, Masahito Shigemitsu, Akitomo Yamamoto, Akira Oka, Naohiko Ohkouchi
  • Organizer: JPGU2022
  • Int'l Joint Research
• [Presentation] Yoshikawa, C., M. Shigemitsu, A. Yamamoto, A. Oka, N. Ohkouchi Nitrogen isotope mapping in the North Pacific using a marine nitrogen isotope model. (2021)
  • Author(s): Yoshikawa, C., M. Shigemitsu, A. Yamamoto, A. Oka, N. Ohkouchi
  • Organizer: JPGU Meeting 2021
  • Int'l Joint Research
• [Presentation] Nitrate isotopes in the Bay of Bengal. (2020)
  • Author(s): Yoshikawa, C., A. Makabe, Y. Matsui, S. Toyoda, M.C. Honda, and N. Ohkouchi
  • Organizer: JpGU-AGU Joint Meeting 2020 : Virtual
  • Int'l Joint Research
• [Presentation] 東部インド洋における硝酸の窒素酸素同位体比 (2020)
  • Author(s): 吉川知里、眞壁明子、松井洋平、豊田栄、本多牧生、布浦拓郎、大河内直彦
  • Organizer: 2020年度地球化学会第67回オンライン年会
• [Presentation] Seasonal transition of the dominant nitrogen source for phytoplankton reconstructed by determining the nitrogen isotope composition for nitrate, ammonium, and individual amino acids of sinking particles in the Northwestern Pacific (2020)
  • Author(s): C. Yoshikawa, N.O. Ogawa, Y. Chikaraishi, A. Makabe, Y. Matsui, Y. Sasai, M. Wakita, M.C. Honda, Y. Mino, M.N. Aita, T. Fujiki, T. Nunoura, N. Harada and N. Ohkouchi
  • Organizer: OSM2020
  • Int'l Joint Research