Latest Update：2026/01/08 10:20:20

SAKAI Masaru

Researcher Name: SAKAI Masaru

Div (Section) name/title: Fukushima Regional Collaborative Research Center (FRECC)（Environmental Impact Assessment Section）／Senior Researcher

Degree(s): Ph.D. (Global Environmental Studies)

Professional Qualification(s): Biology

Environmental Speciality Field: River ecosystem,Forest ecosystem,Agroecosystem

Research Subject

Fiscal Year: 2025
- 27226 : Research of environmental impacts and management in the disaster areas of Fukushima
- 27229 : Studies for emergence of regional resources and systems at Hama-dori, Fukushima, lifted the evacuation instruction
- 27233 : Research on evaluation and clarification of effects and mechanisms of climate change
- 27234 : Research on Advancement of Climate Change Impact Assessment Methodology
- 27247 : Regional Environment Conservation Domain: Foresight and Advanced Basic Research
- 27363 : Intellectual research infrastructure development：Systematic monitoring, development of information on impact prediction and adaptation, and development of tools in the field of climate change adaptation
Fiscal Year: 2024
- 26843 : Research of environmental impacts and management in the disaster areas of Fukushima
- 26845 : Studies for emergence of regional resources and systems at Hama-dori, Fukushima, lifted the evacuation instruction
- 26848 : Research on evaluation and clarification of effects and mechanisms of climate change
- 26849 : Research on Advancement of Climate Change Impact Assessment Methodology
- 26864 : Regional Environment Conservation Domain: Foresight and Advanced Basic Research
- 26899 : Monitoring the dynamics of radiocesium in a multi-media environment
- 27100 : Intellectual research infrastructure development：Systematic monitoring, development of information on impact prediction and adaptation, and development of tools in the field of climate change adaptation
Fiscal Year: 2023
- 26430 : Research of environmental impacts and management in the disaster areas of Fukushima
- 26432 : Studies for emergence of regional resources and systems at Hama-dori, Fukushima, lifted the evacuation instruction
- 26435 : Research on evaluation and clarification of effects and mechanisms of climate change
- 26436 : Research on Advancement of Climate Change Impact Assessment Methodology
- 26453 : Regional Environment Conservation Domain: Foresight and Advanced Basic Research
- 26627 : Monitoring the dynamics of radiocesium in a multi-media environment
- 26736 : Intellectual research infrastructure development：Systematic monitoring, development of information on impact prediction and adaptation, and development of tools in the field of climate change adaptation
- 26772 : Understanding the dynamics of animal communities and the maintenance of biodiversity in interactions among spring-fed and runoff streams
Fiscal Year: 2022
- 25995 : Research of environmental impacts and management in the disaster areas of Fukushima
- 25997 : Studies for emergence of regional resources and systems at Hama-dori, Fukushima, lifted the evacuation instruction
- 26001 : Research on evaluation and clarification of effects and mechanisms of climate change
- 26002 : Research on Advancement of Climate Change Impact Assessment Methodology
- 26010 : Regional Environment Conservation Domain: Foresight and Advanced Basic Research
- 26035 : Monitoring the dynamics of radiocesium in a multi-media environment
- 26293 : Intellectual research infrastructure development：Systematic monitoring, development of information on impact prediction and adaptation, and development of tools in the field of climate change adaptation
Fiscal Year: 2021
- 25527 : Research of environmental impacts and management in the disaster areas of Fukushima
- 25529 : Studies for emergence of regional resources and systems at Hama-dori, Fukushima, lifted the evacuation instruction
- 25535 : Research on evaluation and clarification of effects and mechanisms of climate change
- 25536 : Research on Advancement of Climate Change Impact Assessment Methodology
- 25674 : Intellectual research infrastructure development：Systematic monitoring, development of information on impact prediction and adaptation, and development of tools in the field of climate change adaptation
- 25713 : Regional Environment Conservation Domain: Foresight and Advanced Basic Research
- 25766 : Monitoring the dynamics of radiocesium in a multi-media environment
- 25930 : Ecosystem functions of spring-fed streams in maintaining biodiversity in river networks
Fiscal Year: 2020
- 25375 : Ecosystem functions of spring-fed streams in maintaining biodiversity in river networks

View all

Research Result (Publication)

all
Original Paper
Review
Book

Review
Bridging ecology and geosciences in riverscapes: implications for process-based restoration

Presenter : Uno H., Nakagawa H., Ishiyama N., Sakai M., Mori T., Terui A., Scholl E.A., Wohl E., Baxter C.V.
Title : , Ecological Research, 41:e70028 (2026)
Original Paper
Frog assemblage patterns in a small-scaled traditional rice paddy (yatsuda) area in Japan

Presenter : Naito R.S., Ichihara R., Sakai M., Hiratsuka M.
Title : , Community Ecology (2025)
Original Paper
Response of 137Cs dynamics in dam lakes to temperature and weather conditions

Presenter : Tsuji H., Nishikiori T., Ito S., Ozaki H., Watanabe Mirai., Sakai M., Ishii Y., Hayashi S.
Title : , Environmental Pollution, 378(1): (2025)
Original Paper
Amphibious feeding mode in an anguillid fish

Presenter : Wakiya R., Sakai M., Suzuki T.N., Kojima Y., Itakura H., Matsuoka M., Kaifu K.
Title : , Ecology, 106(10):e70202 (2025)
Original Paper
Roles of rice paddies and neighboring biotopes with different hydroperiods in providing habitats for an endangered pond frog population in Japan

Presenter : Naito R.S., Sakai M., Natuhara Y., Morimoto Y.
Title : , Wetlands, 44(21): (2024)
Original Paper
Exploring simple ways to avoid collecting highly 137Cs-contaminated Aralia elata buds for the revival of local wild vegetable cultures

Presenter : Sakai M., Watanabe Mirai., Koshikawa-K.m., Tanaka A., Takahashi A., Takechi S., Takagi M., Tsuji T., Tsuji H., Takeda T., Jo J., Tamaoki M., Hayashi S.
Title : , PLOS ONE, 19(4):e0292206 (2024)
Original Paper
Ecosystem functions of a spring-fed tributary in providing foraging habitat and thermal refuge for juvenile masu salmon

Presenter : Sakai M., Hoshi G., Wakiya R.
Title : , Ichthyology and Herpetology, 111(1):44-53 (2023)
Original Paper
Catchment-scale deer exclusion changes longitudinal patterns of macroinvertebrate communities through soil runoff mitigation

Presenter : Sakai M.
Title : , Ecological Engineering, 190:106932 (2023)
Original Paper
Real-time monitoring and postprocessing of thermal infrared video images for sampling and mapping groundwater discharge

Presenter : Iwasaki K., Fukushima K., Nagasaka Y., Ishiyama N., Sakai M., Nagasaka A.
Title : , Water Resources Research, 59: (2023)
Original Paper
Intraspecific variation in advertisement call characteristics and acoustic strategies among male forest green tree frogs

Presenter : Itakura N., Sakai M., Sato R., Nishihara S., Yoshida T., Washitani I.
Title : , Population Ecology (2023)
Original Paper
Spatiotemporal patterns in differences between the 137Cs concentrations of forest and stream litters: Effect of leaching

Presenter : Sakai M., Ohira M., Gomi T.
Title : , Environmental Science: Processes & Impacts (2023)
Original Paper
Influential factors of long-term and seasonal 137Cs change in agricultural and forested rivers: Temperature, water quality and an intense Typhoon Event

Presenter : Tsuji H., Nishikiori T., Ito S., Ozaki H., Watanabe Mirai., Sakai M., Ishii Y., Hayashi S.
Title : , Environmental Pollution (2023)
Book
Spring ecosystems in Japan: Knowledge and perspectives

Presenter : Sakai M., Naito R.S., Bauman D.
Title : , Springs of the World: Distribution, Ecology, and Conservation Status (2023)
Original Paper
Explaining the variation in 137Cs aggregated transfer factor for wild edible plants as a case study on Koshiabura (Eleutherococcus sciadophylloides) buds

Presenter : Hayashi S., Watanabe Mirai., Koshikawa-K.m., Takada M., Takechi S., Takagi M., Sakai M., Tamaoki M.
Title : , Scientific Reports, 13(14162): (2023)
Original Paper
eDNA metabarcoding analysis reveals the consequence of creating ecosystems-scale refugia from deer grazing for the soil microbial communities

Presenter : Kadowaki K., Honjo M.N., Nakamura N., Kitagawa Y., Ishihara M.I., Matsuoka S., Tachiki Y., Fukushima K., Sakaguchi S., Mizuki I., Fujiki D., Sakai M., Takayanagi A., Yamasaki M., Tokuchi N., Takahashi D., Nagasawa K., Masuda K.
Title : , Environmental DNA (2023)
Book
Indirect effects of deer overgrazing on stream ecosystems

Presenter : Sakai M., Fukushima K., Nakagawa H.
Title : , Sika deer: life history plasticity and management (2022)
Original Paper
Relationships between the eDNA concentration obtained from metabarcoding and stream fish abundance estimated by the removal method under field conditions

Presenter : Nakagawa H., Fukushima K., Sakai M., Wu L., Minamoto T.
Title : , Environmental DNA (2022)
Original Paper
Contrasting seasonality of 137Cs concentrations in two stream animals that share a trophic niche

Presenter : Sakai M., Ishii Y., Tsuji H., Tanaka A., Jo J., Negishi J.N., Hayashi S.
Title : , Environmental Pollution, (120474): (2022)
Original Paper
Unique habitat and macroinvertebrate assemblage structures in spring-fed stream: a comparison among clastic lowland tributaries and mainstreams in northern Japan

Presenter : Sakai M., Iwabuchi K., Bauman D.
Title : , Community Ecology (2021)
Original Paper
Flood-induced interspecific interactions in spring-fed tributary as an ecosystem function of heterogeneous river networks

Presenter : Sakai M., Wakiya R., Hoshi G.
Title : , Landscape and Ecological Engineering (2021)
Review
Untangling radiocesium dynamics of forest-stream ecosystems: A review of Fukushima studies in the decade after the accident

Presenter : Sakai M., Tsuji H., Ishii Y., Ozaki H., Takechi S., Jo J., Tamaoki M., Hayashi S., Gomi T.
Title : , Environmental Pollution, 288(117744): (2021)
Original Paper
Long-term impacts of forest disturbances: Comparing cumulative effects of clearcut logging versus landslide on stream conditions and abundance of a headwater stonefly Scopura montana

Presenter : Ohira M., Watanabe Y., Gomi T., Sakai M.
Title : , Freshwater Biology (2021)
Original Paper
Seasonal variations of 137Cs concentration in freshwater charr through uptake and metabolism in 1-2 years after the Fukushima accident

Presenter : Okada K., Sakai M., Gomi T., Iwamoto A., Negishi J.N., Nunokawa M.
Title : , Ecological Research (2021)
Book
Characteristics of 137Cs concentration and radioactivity transfer in large aquatic insect species

Presenter : Fujino T., Senavirathna M.D.H.J, Sakai M., Gomi T.
Title : , Impacts of Fukushima nuclear accident on freshwater environments (2021)
Original Paper
Seasonal and annual fluctuations of deer populations estimated by a Bayesian state-space model

Presenter : Mizuki I., Ito H., Yamasaki M., Fukumoto S., Okamoto Y., Katsuki M., Fukushima K., Sakai M., Sakaguchi S., Fujiki D., Nakagawa H., Ishihara MI., Takayanagi A.
Title : , PLOS ONE, 15(e0225872): (2020)

View all

Frog assemblage patterns in a small-scaled traditional rice paddy (yatsuda) area in Japan

Presenter : Naito R.S., Ichihara R., Sakai M., Hiratsuka M.
Title : , Community Ecology (2025)
Response of 137Cs dynamics in dam lakes to temperature and weather conditions

Presenter : Tsuji H., Nishikiori T., Ito S., Ozaki H., Watanabe Mirai., Sakai M., Ishii Y., Hayashi S.
Title : , Environmental Pollution, 378(1): (2025)
Amphibious feeding mode in an anguillid fish

Presenter : Wakiya R., Sakai M., Suzuki T.N., Kojima Y., Itakura H., Matsuoka M., Kaifu K.
Title : , Ecology, 106(10):e70202 (2025)
Roles of rice paddies and neighboring biotopes with different hydroperiods in providing habitats for an endangered pond frog population in Japan

Presenter : Naito R.S., Sakai M., Natuhara Y., Morimoto Y.
Title : , Wetlands, 44(21): (2024)
Exploring simple ways to avoid collecting highly 137Cs-contaminated Aralia elata buds for the revival of local wild vegetable cultures

Presenter : Sakai M., Watanabe Mirai., Koshikawa-K.m., Tanaka A., Takahashi A., Takechi S., Takagi M., Tsuji T., Tsuji H., Takeda T., Jo J., Tamaoki M., Hayashi S.
Title : , PLOS ONE, 19(4):e0292206 (2024)
Ecosystem functions of a spring-fed tributary in providing foraging habitat and thermal refuge for juvenile masu salmon

Presenter : Sakai M., Hoshi G., Wakiya R.
Title : , Ichthyology and Herpetology, 111(1):44-53 (2023)
Catchment-scale deer exclusion changes longitudinal patterns of macroinvertebrate communities through soil runoff mitigation

Presenter : Sakai M.
Title : , Ecological Engineering, 190:106932 (2023)
Real-time monitoring and postprocessing of thermal infrared video images for sampling and mapping groundwater discharge

Presenter : Iwasaki K., Fukushima K., Nagasaka Y., Ishiyama N., Sakai M., Nagasaka A.
Title : , Water Resources Research, 59: (2023)
Intraspecific variation in advertisement call characteristics and acoustic strategies among male forest green tree frogs

Presenter : Itakura N., Sakai M., Sato R., Nishihara S., Yoshida T., Washitani I.
Title : , Population Ecology (2023)
Spatiotemporal patterns in differences between the 137Cs concentrations of forest and stream litters: Effect of leaching

Presenter : Sakai M., Ohira M., Gomi T.
Title : , Environmental Science: Processes & Impacts (2023)
Influential factors of long-term and seasonal 137Cs change in agricultural and forested rivers: Temperature, water quality and an intense Typhoon Event

Presenter : Tsuji H., Nishikiori T., Ito S., Ozaki H., Watanabe Mirai., Sakai M., Ishii Y., Hayashi S.
Title : , Environmental Pollution (2023)
Explaining the variation in 137Cs aggregated transfer factor for wild edible plants as a case study on Koshiabura (Eleutherococcus sciadophylloides) buds

Presenter : Hayashi S., Watanabe Mirai., Koshikawa-K.m., Takada M., Takechi S., Takagi M., Sakai M., Tamaoki M.
Title : , Scientific Reports, 13(14162): (2023)
eDNA metabarcoding analysis reveals the consequence of creating ecosystems-scale refugia from deer grazing for the soil microbial communities

Presenter : Kadowaki K., Honjo M.N., Nakamura N., Kitagawa Y., Ishihara M.I., Matsuoka S., Tachiki Y., Fukushima K., Sakaguchi S., Mizuki I., Fujiki D., Sakai M., Takayanagi A., Yamasaki M., Tokuchi N., Takahashi D., Nagasawa K., Masuda K.
Title : , Environmental DNA (2023)
Relationships between the eDNA concentration obtained from metabarcoding and stream fish abundance estimated by the removal method under field conditions

Presenter : Nakagawa H., Fukushima K., Sakai M., Wu L., Minamoto T.
Title : , Environmental DNA (2022)
Contrasting seasonality of 137Cs concentrations in two stream animals that share a trophic niche

Presenter : Sakai M., Ishii Y., Tsuji H., Tanaka A., Jo J., Negishi J.N., Hayashi S.
Title : , Environmental Pollution, (120474): (2022)
Unique habitat and macroinvertebrate assemblage structures in spring-fed stream: a comparison among clastic lowland tributaries and mainstreams in northern Japan

Presenter : Sakai M., Iwabuchi K., Bauman D.
Title : , Community Ecology (2021)
Flood-induced interspecific interactions in spring-fed tributary as an ecosystem function of heterogeneous river networks

Presenter : Sakai M., Wakiya R., Hoshi G.
Title : , Landscape and Ecological Engineering (2021)
Long-term impacts of forest disturbances: Comparing cumulative effects of clearcut logging versus landslide on stream conditions and abundance of a headwater stonefly Scopura montana

Presenter : Ohira M., Watanabe Y., Gomi T., Sakai M.
Title : , Freshwater Biology (2021)
Seasonal variations of 137Cs concentration in freshwater charr through uptake and metabolism in 1-2 years after the Fukushima accident

Presenter : Okada K., Sakai M., Gomi T., Iwamoto A., Negishi J.N., Nunokawa M.
Title : , Ecological Research (2021)
Seasonal and annual fluctuations of deer populations estimated by a Bayesian state-space model

Presenter : Mizuki I., Ito H., Yamasaki M., Fukumoto S., Okamoto Y., Katsuki M., Fukushima K., Sakai M., Sakaguchi S., Fujiki D., Nakagawa H., Ishihara MI., Takayanagi A.
Title : , PLOS ONE, 15(e0225872): (2020)

View all

Bridging ecology and geosciences in riverscapes: implications for process-based restoration

Presenter : Uno H., Nakagawa H., Ishiyama N., Sakai M., Mori T., Terui A., Scholl E.A., Wohl E., Baxter C.V.
Title : , Ecological Research, 41:e70028 (2026)
Untangling radiocesium dynamics of forest-stream ecosystems: A review of Fukushima studies in the decade after the accident

Presenter : Sakai M., Tsuji H., Ishii Y., Ozaki H., Takechi S., Jo J., Tamaoki M., Hayashi S., Gomi T.
Title : , Environmental Pollution, 288(117744): (2021)

View all

Spring ecosystems in Japan: Knowledge and perspectives

Presenter : Sakai M., Naito R.S., Bauman D.
Title : , Springs of the World: Distribution, Ecology, and Conservation Status (2023)
Indirect effects of deer overgrazing on stream ecosystems

Presenter : Sakai M., Fukushima K., Nakagawa H.
Title : , Sika deer: life history plasticity and management (2022)
Characteristics of 137Cs concentration and radioactivity transfer in large aquatic insect species

Presenter : Fujino T., Senavirathna M.D.H.J, Sakai M., Gomi T.
Title : , Impacts of Fukushima nuclear accident on freshwater environments (2021)

View all

Research Result (Presentation)

all
Research Presentation
Research Lecture

Research Lecture
Ecosystem functions of spring-fed habitats in heterogeneous river environments

Presenter : Sakai M.
Name of Society : 第71回日本生態学会大会 (2024)
Name of Proceedings : -
Research Presentation
Competition differentiates Cs-137 concentrations in between sympatric salmonids in a highly contaminated zone

Presenter : Sakai M., Ishii Y., Hayashi S., Takasaki K., Teramoto W., Funaki Y., Kanasashi T., Wada T.
Name of Society : 6th International Conference on Radioecology & Environmental Radioactivity (2024)
Name of Proceedings : -
Research Presentation
Stable isotope analysis reveals the important 137Cs sources for fish in river and lake food webs in Fukushima

Presenter : Ishii Y., Matsuzaki S., Nakagawa M., Jo J., Sakai M., Wada T., Kanasashi T., Takasaki K., Teramoto W., Funaki Y., Hayashi S.
Name of Society : 6th International Conference on Radioecology & Environmental Radioactivity (2024)
Name of Proceedings : -
Research Lecture
Dynamics of radiocesium in rivers and dam lakes

Presenter : Tsuji H., Ishii Y., Sakai M., Hayashi S.
Name of Society : 第34回台日工程技術研討會 (2023)
Name of Proceedings : -
Research Presentation
Deer overgrazing alters stream water chemistry in forested catchments: importance of understory vegetation in nutrient retention

Presenter : Fukushima K., Sakaguchi S., Sakai M., Mizuki I., Fujiki D., Nakagawa H., Yamasaki M., Ishihara M., Takayanagi A.
Name of Society : 69th Annual Meeting of Ecological Society of Japan (2022)
Name of Proceedings : -
Research Presentation
Nitrate contamination of mountainous headwater streams from adjacent agricultural and pasture lands beyond the watershed boundary in eastern Hokkaido, Japan

Presenter : Fukushima K., Iwasaki K., Sakai M., Oda Y., Koba K., Katata G., Yamaguchi T., Kubota T., Nagano H., Watanabe M., Koarashi J.
Name of Society : JpGU-AGU Joint Meeting 2020 (2020)
Name of Proceedings : -

View all

Competition differentiates Cs-137 concentrations in between sympatric salmonids in a highly contaminated zone

Presenter : Sakai M., Ishii Y., Hayashi S., Takasaki K., Teramoto W., Funaki Y., Kanasashi T., Wada T.
Name of Society : 6th International Conference on Radioecology & Environmental Radioactivity (2024)
Name of Proceedings : -
Stable isotope analysis reveals the important 137Cs sources for fish in river and lake food webs in Fukushima

Presenter : Ishii Y., Matsuzaki S., Nakagawa M., Jo J., Sakai M., Wada T., Kanasashi T., Takasaki K., Teramoto W., Funaki Y., Hayashi S.
Name of Society : 6th International Conference on Radioecology & Environmental Radioactivity (2024)
Name of Proceedings : -
Deer overgrazing alters stream water chemistry in forested catchments: importance of understory vegetation in nutrient retention

Presenter : Fukushima K., Sakaguchi S., Sakai M., Mizuki I., Fujiki D., Nakagawa H., Yamasaki M., Ishihara M., Takayanagi A.
Name of Society : 69th Annual Meeting of Ecological Society of Japan (2022)
Name of Proceedings : -
Nitrate contamination of mountainous headwater streams from adjacent agricultural and pasture lands beyond the watershed boundary in eastern Hokkaido, Japan

Presenter : Fukushima K., Iwasaki K., Sakai M., Oda Y., Koba K., Katata G., Yamaguchi T., Kubota T., Nagano H., Watanabe M., Koarashi J.
Name of Society : JpGU-AGU Joint Meeting 2020 (2020)
Name of Proceedings : -

View all

Ecosystem functions of spring-fed habitats in heterogeneous river environments

Presenter : Sakai M.
Name of Society : 第71回日本生態学会大会 (2024)
Name of Proceedings : -
Dynamics of radiocesium in rivers and dam lakes

Presenter : Tsuji H., Ishii Y., Sakai M., Hayashi S.
Name of Society : 第34回台日工程技術研討會 (2023)
Name of Proceedings : -

View all

SAKAI Masaru

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