Decadal changes in ocean climate and zooplankton biomass associated with recent sea ice reduction in the Arctic Ocean

• Project/Area Number: 16K00533
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Environmental dynamic analysis
• Research Institution: Japan Agency for Marine-Earth Science and Technology
• Principal Investigator: ITOH Motoyo 国立研究開発法人海洋研究開発機構, 地球環境部門(北極環境変動総合研究センター), 副主任研究員 (60373453)
• Project Period (FY): 2016-04-01 – 2021-03-31
• Project Status: Completed (Fiscal Year 2020)
• Budget Amount: ¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000); Fiscal Year 2019: ¥1,040,000 (Direct Cost: ¥800,000、Indirect Cost: ¥240,000); Fiscal Year 2018: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000); Fiscal Year 2017: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2016: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
• Keywords: 北極海 / 海洋物理 / 海洋生態 / 環境変動

Outline of Final Research Achievements

Sea ice cover is rapidly declining due to global warming in the Arctic Ocean. However, their influences on marine ecosystems remain unclear because few studies have conducted long-term ecological monitoring at decadal time scales. Mooring-based acoustic backscattering data collected during periods of both high (2000-03) and low sea ice coverage (2010-13) in Barrow Canyon, are used to show that the annual mean zooplankton biomass increased 1.6 hold between the two periods. Our calculations suggest that this biomass change would have increased the grazing pressure by zooplankton, which, in turn, decreased the supply of sinking carbon to benthic organisms during summer, even though phytoplankton production would have increased. Thus, the Chukchi Sea ecosystem is now shifting away from a pelagic-benthic coupled ecosystem towards one that is pelagic-dominated, in which the primary production is not directly connected to the benthic carbon cycle due to increased pelagic zooplankton grazing.

Academic Significance and Societal Importance of the Research Achievements

本研究で示された動物プランクトン量の増加は摂餌圧の変化を通して、海洋生態系の食物連鎖網に影響を与える。動物プランクトンは、太平洋側北極海の主要な魚類である北極タラ、サケの餌となるため、漁業資源の変動にも影響する可能性がある。バロー海底谷で観測された、動物プランクトン量の増加、植物プランクトンへの摂餌圧の増加、底生生物への有機物供給量の減少は、海氷減少が発端となって起こっている。そのため、今後も更なる海氷減少が予測される北極海での食物連鎖網の変化の端緒を捉えた可能性がある。

Research Products

• [Journal Article] Mean and seasonal circulation of the eastern Chukchi Sea from moored timeseries in 2013‐14 (2021)
  • Author(s): Tian Fei、Pickart Robert S.、Lin Peigen、Pacini Astrid、Moore G.W.K.、Stabeno Phyllis、Weingartner Thomas、Itoh Motoyo、Kikuchi Takashi、Dobbins Elizabeth、Bell Shaun、Woodgate Rebecca A.、Danielson Seth L.、Wang Zhaomin
  • Journal Title: Journal of Geophysical Research: Oceans Volume: - Issue: 5
  • DOI: 10.1029/2020jc016863
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Analysis of the Beaufort Gyre freshwater content in 2003-2018 (2019)
  • Author(s): Proshutinsky, A., R. Krishfield, J. Toole, M.-L. Timmermans, W. Williams, S. Zimmerman, M. Yamamoto-Kawai, T. W. K. Armitage, D. Dukhovskoy, E. Golubeva, G. E. Manucharyan, G. Platov, E. Watanabe, T. Kikuchi, S. Nishino, M. Itoh, S.-H. Kang, K.-H. Cho, K. Tateyama, and J. Zhao
  • Journal Title: JOURNAL OF GEOPHYSICAL RESEARCH - Oceans Volume: 124 Issue: 12 Pages: 9658-9689
  • DOI: 10.1029/2019jc015281
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] The warming of the Chukchi slope through the Barrow Canyon outflow in the 2016‐2017 winter (2019)
  • Author(s): Kimura, S., J. Onodera, M. Itoh, T. Kikuchi, S. Nishino, Y. Kawaguchi, E. Watanabe, and N. Harada
  • Journal Title: JOURNAL OF GEOPHYSICAL RESEARCH - Oceans Volume: 124 Issue: 11 Pages: 7437-7456
  • DOI: 10.1029/2019jc015093
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Seasonal to mesoscale variability of water masses and atmospheric conditions in Barrow Canyon, Chukchi Sea (2019)
  • Author(s): Pickart, R., C. Nobre, P. Lin, K. Arrigo, C. Ashjian, C. Berchok, L. Cooper, J. Grebmeier, I. Hartwell, J. He, M. Itoh, T. Kikuchi, S. Nishino, and S. Vagle
  • Journal Title: Deep Sea Research Part II Volume: in press Pages: 32-49
  • DOI: 10.1016/j.dsr2.2019.02.003
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Interannual variation in solar heating in the Chukchi Sea, Arctic Ocean (2018)
  • Author(s): Tsukada, Y., H. Ueno, N. Ohta, M. Itoh, E. Watanabe, T. Kikuchi, S. Nishino, and K. Mizobata
  • Journal Title: Polar Science Volume: 17 Pages: 33-39
  • DOI: 10.1016/j.polar.2018.06.003
  • NAID: 120006882067
  • Peer Reviewed / Open Access
• [Journal Article] Transport of Pacific Water into the Canada Basin and the formation of the Chukchi Slope Current (2018)
  • Author(s): Spall, M. A., R. S. Pickart, M. Li, M. Itoh, P. Lin, T. Kikuchi, and Y. Qi
  • Journal Title: Journal of Geophysical Research Volume: 123(10) Issue: 10 Pages: 7453-7471
  • DOI: 10.1029/2018jc013825
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Winter water formation in coastal polynyas of the eastern Chukchi shelf: Pacific and Atlantic influences (2018)
  • Author(s): Hirano, D., Y. Fukamachi, K. I. Ohshima, E. Watanabe, A. R. Mahoney, H. Eicken, M. Itoh, D. Simizu, K. Iwamoto, J. Jones, T. Takatsuka, T. Kikuchi, and T. Tamura
  • Journal Title: Journal of Geophysical Research Volume: 123 Issue: 8 Pages: 5688-5705
  • DOI: 10.1029/2017jc013307
  • NAID: 120006559016
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Year-round observations of sea-ice drift and near-inertial internal waves in the Northwind Abyssal Plain, Arctic Ocean (2018)
  • Author(s): Kawaguchi, Y., M. Itoh, Y. Fukamachi, E. Moriya, J. Onodera, T. Kikuchi and N. Harada
  • Journal Title: Polar Science Volume: in press Pages: 1-9
  • DOI: 10.1016/j.polar.2019.01.004
  • Peer Reviewed / Open Access
• [Presentation] Increasing zooplankton biomass associated with sea ice loss in the western Arctic Ocean (2021)
  • Author(s): Motoyo Itoh , Minoru Kitamura , Amane Fujiwara , Eddy Carmack , Kazuo Amakasu , Koichi Ara , Mario Uchimiya , Toru Hirawake , Jonaotaro Onodera , Shigeto Nishino , Takashi Kikuch
  • Organizer: Alaska Marine Science Symposium
  • Int'l Joint Research
• [Presentation] Long term variability of Barrow Canyon fluxes and its impact on subsurface warming in the western Arctic Ocean (2021)
  • Author(s): Motoyo Itoh, Takashi Kikuchi, Shigeto Nishino
  • Organizer: Arctic Science Summit Week 2021
  • Int'l Joint Research
• [Presentation] Preliminary results of the R/V Mirai Arctic Ocean cruise in 2020 (2021)
  • Author(s): Nishino Shigeto, Amane Fujiwara, Motoyo Itoh, Jonaotaro Onodera, Akihiko Murata, Takashi Kikuchi
  • Organizer: Arctic Science Summit Week 2021 Science Conference
  • Int'l Joint Research
• [Presentation] Mean and Seasonal Circulation of the Eastern Chukchi Sea from Moored Timeseries in 2013‐ 14 (2021)
  • Author(s): Robert Pickart, Fei Tian, Peigen Lin, Astrid Pacini, Kent Moore, Phyllis Stabeno, Thomas Weingartner, Motoyo Itoh, Takashi Kikuchi, Elizabeth Dobbins, Shaun Bell, Rebecca Woodgate, Zhaomin Wang
  • Organizer: Alaska Marine Science Symposium
  • Int'l Joint Research
• [Presentation] Increasing zooplankton biomass associated with sea ice loss in the western Arctic Ocean (2020)
  • Author(s): Motoyo Itoh , Minoru Kitamura , Amane Fujiwara , Eddy Carmack , Kazuo Amakasu , Koichi Ara , Mario Uchimiya , Toru Hirawake , Jonaotaro Onodera , Shigeto Nishino , Takashi Kikuch
  • Organizer: JpGU-AGU Joint Meeting 2020
  • Int'l Joint Research
• [Presentation] Summary of the R/V Mirai Arctic Ocean cruise in 2020 (2020)
  • Author(s): Nishino Shigeto, Amane Fujiwara, Motoyo Itoh, Jonaotaro Onodera, Akihiko Murata, Takashi Kikuchi
  • Organizer: The 11th symposium on polar science
  • Int'l Joint Research
• [Presentation] 北極海バロー海底谷を通過する夏季太平洋水の昇温 (2020)
  • Author(s): 伊東素代, 菊地隆, 西野茂人
  • Organizer: 日本海洋学会 2020 年度秋季大会
• [Presentation] Long term variability of Barrow Canyon fluxes and its impact on subsurface warming in the western Arctic Ocean (2020)
  • Author(s): Itoh, M., T. Kikuchi, S. Nishino
  • Organizer: Sixth International Symposium on the Arctic Research (ISAR-6) Online Meeting
  • Int'l Joint Research
• [Presentation] Pacific water in the northeastern Chukchi Sea (2020)
  • Author(s): Muramatsu, M., H. Ueno, M. Itoh, E. Watanabe, and J. Onodera
  • Organizer: Sixth International Symposium on the Arctic Research (ISAR-6) Online Meeting
  • Int'l Joint Research
• [Presentation] The warming of the Chukchi slope through the Barrow Canyon outflow in the 2016‐2017 winter (2020)
  • Author(s): Kimura, S., J. Onodera, M. Itoh, T. Kikuchi, S. Nishino, Y. Kawaguchi, E. Watanabe, N. Harada
  • Organizer: Ocean Sciences Meeting 2020
  • Int'l Joint Research
• [Presentation] Long term variability of Barrow Canyon fluxes and its impact on sub surface warming in the Canada Basin (2019)
  • Author(s): Itoh, M., T. Kikuchi, S. Nishino
  • Organizer: 17th ASOF-ISSG Meeting and Workshop
  • Int'l Joint Research
• [Presentation] Nutrient and phytoplankton distributions associated with ocean circulation, eddies, and mixing in the Pacific Arctic Region (2019)
  • Author(s): Nishino, S., A. Fujiwara, Y. Kawaguchi, T. Shiozaki, M. Itoh, T. Hirawake, M. Yamamoto-Kawai, M. Aoyama, N. Harada, T. Kikuchi
  • Organizer: Future Oceans 2 - the 2nd IMBeR Open Science Conference
  • Int'l Joint Research
• [Presentation] チャクチ海北東部陸棚縁辺部における太平洋起源水の移流 (2019)
  • Author(s): 村松美幌, 上野洋路, 伊東素代, 渡邉英嗣, 小野寺丈尚太郎
  • Organizer: 日本海洋学会秋季大会
• [Presentation] Pacific water in the northeastern Chukchi Sea (2019)
  • Author(s): Muramatsu, M., H. Ueno, M. Itoh, E. Watanabe, J. Onodera
  • Organizer: The North Pacific Marine Science Organization (PICES) 2019 Annual Meeting
  • Int'l Joint Research
• [Presentation] Particle flux change reflecting input of Pacific-origin water in the southwestern Canada Basin (2019)
  • Author(s): Onodera, J., S. Kimura, M. Itoh, E. Watanabe, K. Mizobata, Y. Tanaka, N. Harada
  • Organizer: Future Oceans 2 - the 2nd IMBeR Open Science Conference
  • Int'l Joint Research
• [Presentation] High resolution sea ice motion analysis with MODIS data in the western Arctic region (2019)
  • Author(s): Yaguchi, S., N. Kimura, M. Itoh, Y. Fukamachi, T. Kikuchi, and H. Yamaguchi
  • Organizer: The 34th International Symposium on the Okhotsk Sea and Polar Ocean 2019
  • Int'l Joint Research
• [Presentation] 西野茂人、藤原周、川口悠介、菊地隆、伊東素代 2017年「みらい」北極航海概要と観測結果の報告 (2019)
  • Author(s): 西野茂人、藤原周、川口悠介、菊地隆、伊東素代
  • Organizer: ブルーアースサイエンス・テク2019
• [Presentation] On the warming of the Chukchi slope through the Barrow Canyon outflow in the winter of 2016-17 (2019)
  • Author(s): Kimura, S., J. Onodera, M. Itoh, T. Kikuchi, and S. Nishino
  • Organizer: Polar Marine Science (GRS) Gordon Research Seminar
  • Int'l Joint Research
• [Presentation] Brief update of recent activities and results for DBO: Japan DBO results (2018)
  • Author(s): Itoh, M.
  • Organizer: Pacific Arctic Group 2018 Fall meeting
  • Int'l Joint Research
• [Presentation] 2017年「みらい」北極航海概要/Summary of the R/V Mirai Arctic Ocean cruise in 2017 (2018)
  • Author(s): 西野茂人、藤原周、川口悠介、菊地隆、伊東素代
  • Organizer: JpGU2018 日本地球惑星科学連合2018年大会
  • Int'l Joint Research
• [Presentation] Jonaotaro Onodera, Eiji Watanabe, Kohei Mizobata, Yuichiro Tanaka, Motoyo Itoh, Naomi Harada Lateral advection of biogenic particles in the southwestern Canada Basin, Arctic Ocean (2018)
  • Author(s): Onodera, J., E. Watanabe, K. Mizobata, Y. Tanaka, M. Itoh, and N. Harada
  • Organizer: JpGU2018 日本地球惑星科学連合2018年大会
  • Int'l Joint Research
• [Presentation] チャクチ海北東部陸棚縁辺部における太平洋起源水の移流 (2018)
  • Author(s): 村松美幌、上野洋路、伊東素代、渡邉英嗣、小野寺丈尚太郎
  • Organizer: 日本海洋学会秋季大会
• [Presentation] On the warming of the Chukchi slope through the Barrow Canyon outflow in the winter of 2016-17 (2018)
  • Author(s): Kimura, S., J. Onodera, M. Itoh, T. Kikuchi, and S. Nishino
  • Organizer: Forum for Arctic Modelling and Observational Synthesis 2018 Annual Meeting
  • Int'l Joint Research
• [Presentation] Sea-ice thickness from moored ice-profiling sonar in the Canada Basin, Arctic Ocean (2018)
  • Author(s): M. Itoh, Y. Fukamachi, N. Kimura, R.A. Krishfield, T. Kikuchi, E. Moriya, J. Onodera, N. Harada
  • Organizer: Fifth International Symposium on Arctic Research (ISAR-5)
  • Int'l Joint Research
• [Presentation] Interannual variabilities of Pacific Water inflow into the Arctic basin via Barrow Canyon (2017)
  • Author(s): Itoh, M., T. Kikuchi, S. Nishino
  • Organizer: Alaska Marine Science Symposium
  • Place of Presentation: Anchorage, Alaska, USA
  • Year and Date: 2017-01-24
  • Int'l Joint Research
• [Presentation] Interannual variabilities of Pacific Water inflow into the Arctic basin via Barrow Canyon (2017)
  • Author(s): M. Itoh, T. Kikuchi, S. Nishino
  • Organizer: Arctic Science Summit Week 2017
  • Int'l Joint Research
• [Presentation] Sea-ice thickness from moored ice-profiling sonar in the Canada Basin, Arctic Ocean (2017)
  • Author(s): M. Itoh, Y. Fulamachi, N. Kimura, R.A. Krishfield, T. Kikuchi, E. Moriya, J. Onodera, N. Harada
  • Organizer: Arctic Change 2017
  • Int'l Joint Research
• [Presentation] バロー海底谷における太平洋水のフラックスと北極海の温暖化への影響 (2017)
  • Author(s): 伊東素代, 菊地隆, 西野茂人
  • Organizer: JpGU-AGU Joint Meeting 2017
• [Presentation] 係留系観測による北極海カナダ海盆の海氷厚の季節変動 (2017)
  • Author(s): 伊東素代, 深町康, 木村詞明, R.A. Krishfield, 菊地隆, 守家衣利加, 小野寺丈尚太郎, 原田尚美
  • Organizer: 日本海洋学会2017年秋季大会
• [Presentation] Wind-driven variability in subsurface warm layers of the Chukchi shelf break (2016)
  • Author(s): Watanabe, E., J. Onodera, M. Itoh, S. Nishino, T. Kikuchi
  • Organizer: ArcticNet Annual Scientific Meeting 2016
  • Place of Presentation: Winnipeg, Manitoba, Canada
  • Year and Date: 2016-12-07
  • Int'l Joint Research
• [Presentation] Interannual variabilties of fluxes in Barrow Canyon from 2010-2014 : results from the (2016)
  • Author(s): Itoh, M., T. Kikuchi, Y. Fukamachi, R. Pickart
  • Organizer: 2016 Pacific Arctic Group Fall Meeting
  • Place of Presentation: 青島, 中国
  • Year and Date: 2016-10-27
  • Int'l Joint Research
• [Presentation] 北極海チャクチ陸棚縁における冬季海氷下の亜表層暖水輸送 (2016)
  • Author(s): 渡邉英嗣， 小野寺丈尚太郎， 伊東素代， 西野茂人， 菊地隆
  • Organizer: 日本海洋学会2016年度秋季大会
  • Place of Presentation: 鹿児島大学(鹿児島県鹿児島市)
  • Year and Date: 2016-09-14
• [Presentation] 西部北極海における厳冬期の亜表層暖水輸送 (2016)
  • Author(s): 渡邉英嗣， 小野寺丈尚太郎， 伊東素代， 西野茂人， 菊地隆
  • Organizer: 日本地球惑星科学連合2016年大会
  • Place of Presentation: 幕張メッセ(千葉県千葉市)
  • Year and Date: 2016-05-26