AKIRA UMEHARA

Last Updated :2025/03/03

Affiliations, Positions
Environmental Research and Management Center, Assistant Professor
Web Site
https://www.grpr.hiroshima-u.ac.jp
E-mail
umeharahiroshima-u.ac.jp

Basic Information

Major Professional Backgrounds

  • 2014/04/01, 2017/03/31, Hiroshima University, Environmental Research and Management Center, Postdoctoral fellow
  • 2017/04/01, 2018/03/31, Hiroshima University, Environmental Research and Management Center, Research Assistant Professor

Educational Backgrounds

  • Kumamoto Health Science University, Department of Medical Technology, Japan, 2004/04/01, 2009/03/24
  • Prefectural University of Kumamoto, Faculty of Environmental and Symbiotic Sciences, Japan, 2009/04/01, 2014/03/15

Academic Degrees

  • Prefectural University of Kumamoto
  • Prefectural University of Kumamoto

Research Fields

  • Environmental science;Sustainable and environmental system development;Environmental and ecological symbiosis

Research Keywords

  • Biotic Index
  • Cyanobacteria
  • Ecology
  • Coastal area
  • Environmental Toxicology
  • Biological productivity

Affiliated Academic Societies

  • Society for Chemical Engineers, Japan
  • The Plankton Society of Japan
  • The Japanese Association of Benthology
  • The Oceanographic Society of Japan
  • The Japanese Society of Limnology
  • Japan Society on Water Environment

Educational Activity

Course in Charge

  1. 2024, Liberal Arts Education Program1, 1Term, Environmental management in higashi-hiroshima campus at Hiroshima University
  2. 2024, Undergraduate Education, 3Term, Practice of General Health and Dental Health I
  3. 2024, Undergraduate Education, 4Term, Practice of General Health and Dental Health II
  4. 2024, Undergraduate Education, 3Term, Basic Environmental Sciences
  5. 2024, Undergraduate Education, Second Semester, Basic Experiments in Chemistry
  6. 2024, Undergraduate Education, Year, Graduation Thesis

Research Activities

Academic Papers

  1. Blooming of Microcystis aeruginosa in the reservoir of the reclaimed land and discharge of microcystins to Isahaya Bay (Japan)., Environmental Science and Pollution Research, 19, 3257-3267, 2012
  2. Species diversity of the genus Skeletonema (Bacillariophyceae) in Japanese brackish water areas, Fisheries Science, 79, 923-934, 2013
  3. Diffusion of microcystins (cyanobacteria hepatotoxins) from the reservoir of Isahaya Bay, Japan, into the marine and surrounding ecosystems as a result of large-scale drainage, Marine Pollution Bulletin, 89, 250-258, 2014
  4. Short-term dynamics of cyanobacterial toxins (microcystins) following a discharge from a coastal reservoir in Isahaya Bay, Japan, Marine Pollution Bulletin, 92, 73-79, 2015
  5. Variations in macrobenthic community structures in relation to environmental variables in the Seto Inland Sea, Japan, Marine Pollution Bulletin, 92, 90-98, 2015
  6. Contribution of the development of the stratification of water to the expansion of dead zone: A sedimentological approach, Estuarine Coastal and Shelf Science, 164, 204-213, 2015
  7. Implications of changes in the benthic environment and decline of macro-benthic communities in the inner part of Ariake Bay in relation to seasonal hypoxia, Plankton and Benthos Research, 10, 187-201, 2015
  8. Spatial and temporal distributions of Secchi depths and chlorophyll a concentrationsin the Suo Nada of the Seto Inland Sea, Japan, exposed to anthropogenic nutrient loading, Science of the Total Envronment, 571, 543-550, 2016
  9. ★, Widespread dispersal and bio-accumulation of toxic microcystins in benthic marine ecosystems, Chemosphere, 167, 492-500, 2017
  10. Filtration Rate of the Ascidian Ciona savignyi and Its Possible Impact., Thalassas: An International Journal of Marine Sciences, 1-7, 2018
  11. Determination and distribution of region-specific background Secchi depth based on long-term monitoring data in the Seto Inland Sea, Japan, Ecological Indicators, 84, 583-589, 2018
    Link to Paper Search Results by DOI
  12. Biomagnification process of total mercury in the macrobenthic communities in an enclosed bay, Isahaya Bay, Kyushu, Japan,, 21, 9-20, 2018
  13. Historical changes in primary production in the Seto Inland Sea, Japan, after implementing regulations to control the pollutant loads., Water Policy, 2018
  14. ★, Biological productivity evaluation at lower trophic levels with intensive Pacific oyster farming of Crassostrea gigas in Hiroshima Bay, Japan, Aquaculture, 495, 311-319, 2018
    Link to Paper Search Results by DOI
  15. Spatial distribution of hydrogen sulfide and sulfur species in coastal marine sediments Hiroshima Bay, Japan, Marine Pollution Bulletin, 133, 891-899, 2018
    Link to Paper Search Results by DOI
  16. Distribution of region-specific background Secchi depth in Tokyo Bay and Ise Bay, Japan, Ecological Indicators, 98, 397-408, 2019
  17. Management of the west-central Seto Inland Sea, Japan: factors controlling spatiotemporal distribution of chlorophyll a concentration and Secchi depth, Water Policy,, 2019
  18. ★, Benthic quality assessment using M-AMBI in the Seto Inland Sea, Japan, Marine Environmental Research, 148, 67-74, 2019
  19. Estimation of production and sedimentation of cyanobacterial toxins (microcystin) based on nutrient budgets in the reservoir of Isahaya Bay, Japan., Ecotoxicology and Environmental Safety, 183, 109477, 2019
  20. Long-term assessment of the environmental conditions of Lake Nakaumi (Japan) Using Multivariate AZTI Marine Biotic Index (M-AMBI), Journal of Water and Environment Technology, 17(6), 2019
  21. Persistent organic pollutants are still present in surface marine sediments from the Seto Inland Sea, Japan, Marine Pollution Bulletin, 149, 2019
  22. Impact of eelgrass bed recovery and expansion on phytoplankton growth through nutrient competition, Journal of Environmental Management, 260, 2020
  23. Annual dynamics of benthic primary production by macrophytes on a sand flat in the eutrophic Hiroshima Bay, Japan, Regional Studies in Marine Science, 34, 2020
  24. Spatial distribution of perfluorinated organic compounds in surface marine sediments from the Seto Inland Sea, Japan, Journal of Water and Environment Technology, 18(4), 226-237, 2020
  25. Estimation of spatial distribution of coastal ocean primary production in Hiroshima Bay, Japan, with a geostationary ocean color satellite, Estuarine, Coastal and Shelf Science, 224, 2020
  26. Organic matter degradation characteristics of coastal marine sediments collected from the Seto Inland Sea, Japan, Marine Chemistry, 225, 2020
  27. Temporal distribution of primary and secondary production estimated from water quality data in the Seto Inland Sea, Japan., Ecological Indicators, 124, 2021
  28. Terrestrial anaerobic digestate composite for fertilization of oligotrophic coastal seas, Journal of Environmental Management, 293, 2021
  29. Increase in sedimentary organic carbon with a change from hypoxic to oxic conditions, Marine Pollution Bulletin, 168, 2021
  30. Responses of the benthic environment to reduction in anthropogenic nutrient loading in the Seto Inland Sea (Japan), based on M-AMBI assessment., Marine Environmental Research, 173, 105509, 2022
  31. Valorization of Solid Food Waste as a Source of Polyunsaturated Fatty Acids using Aurantiochytrium sp. L3W, Waste and Biomass Valorization, 2023
  32. Spatial and temporal distribution of hydrogen sulfide and sulfur species in coastal marine sediments collected from Osaka Bay, Japan, Marine Chemistry, 104233, 2023
  33. Development of a grain-size determination method based on digital images of muddy sediments in coastal areas, Marine Geology, 107066, 2023
  34. Controlling organic carbon increase in oxygenated marine sediments by using decarburization slag, Journal of Environmental Management, 358, 120820, 2024
  35. Cultivation of Aurantiochytrium sp. Using Pickle Seasoning Liquid Waste and Application of the Raw Biomass for Fish Aquaculture, Waste and Biomass Valorization, in press, 2024

Invited Lecture, Oral Presentation, Poster Presentation

  1. Blooming of blue-green algae in the reservoir of Isahaya reclaimed land and its influence on aquatic animals, Umehara A, Tsutsumi H, Takahashi T, Korean and Japan joint symposium on biology of tidal flats, Korea, 2009
  2. Blooming of blue-green algae in the reservoir and dispersion of microcystins to Isahaya Bay, Umehara A, Tsutsumi H, Takahashi T, International symposium on Microcystis studies from Asia, China, 2011
  3. Estimation of the uptake rate of nutrients and the production rate of microcystins by Microcystis based on the mass balance of field observations, Umehara A, Takahashi T, Komorita T, Tsutsumi H, 2012 ASLO aquatic sciences meeting, Japan, 2012
  4. Blooming of toxic cyanobacteria in the Isahaya Bay reservoir (Kyushu, Japan) and the diffusion of microcystins to the marine and terrestrial ecosystems, Takahashi T, Umehara A, Tsutsumi H, 2012 ASLO aquatic sciences meeting, Japan, 2012
  5. Blooming of cyanobacteria in the reservoir of reclaimed land in Isahaya Bay, Japan, and accumulation of toxic substances, microcystins in the coastal ecosystem (Japan), Umehara A, Takahashi T, Komorita T, Orita R, Tsutsumi H, The first Asian marine biology symposium, Thailand, 2012
  6. Diffusion of microcystins from the Isahaya Bay Reservoir to the marine ecosystem of Ariake Bay, Kyushu, Japan (Japan), Takahashi T, Umehara A, Tsutsumi H, The first Asian marine biology symposium, P6-2, Phuket, Thailand, December 2012
  7. Spatial distribution of macro zoobenthos community related to the environmental variables surround a mouth of a small river, southern Japan, Komorita T, Kobayashi J, Ishibashi H, Nakajima N, Ishihara H, Imuta Y, Umehara A, Koga M, Tsutsumi H, The first Asian marine biology symposium, Thailand, 2012
  8. Occurrence of red tides and hypoxic water in an enclosed coastal sea, Ariake Bay, without progressing of eutrophication (Japan), Tsutsumi H, Komorita T, Takahashi T, Umehara A, Orita R, Montani S, The first Asian marine biology symposium, Thailand, 2012
  9. Tsutsumi H. Widespread dispersal and accumulation of toxic substances, microcystins produced by freshwater cyanobacteria in Ariake Bay, the west coast of Kyushu, Japan, Umehara A, Takahashi T, Komorita T, Orita R, Tsutsumi H, The 2nd Asian Marine Biology Symposium, Korea, 2014
  10. Short-term effect of high-turbidity water discharged from a reservoir of reclaimed land onto Isahaya Bay, Kyushu, Japan, Komorita T, Umehara A, Tai A, Takahashi T, Tsutsumi H, The 2nd Asian Marine Biology Symposium, Korea, 2014
  11. Impact of seasonal occurrence of hypoxia on the spatial distributions of bottom environment and macrobenthic communities, Orita R, Umehara A, Komorita T, Tsutsumi H, The 2nd Asian Marine Biology Symposium, Korea, 2014
  12. Poor and abnormal benthos community in the artificial reservoir of Isahaya Bay reclaimed land, and an expectation of change by seawater introduction, Takahashi T, Umehara A, Tsutsumi H, The 2nd Asian Marine Biology Symposium, Korea, 2014
  13. Benthic quality assessment using M-AMBI analysis in Seto Inland Sea, Japan, Umehara A, Nakai S, Okuda T, Nishijima W, Estuarine and Coastal Science Association 55, United Kingdom, 2015
  14. Energy transfer efficiencies on lower trophic levels with intensive oyster farming in Hiroshima Bay, Japan, Umehara A, Asaoka S, Fujii N, Otani S, Yamamoto H, Nakai S, Okuda T, Nishijima W, EMECS11-Sea Coasts XXVI Joint Conference, Russia, 2016
  15. Fate of Silts and Clay from River and its Contribution to Transparency, Okuda T, Sekitou S, Umehara A, Asaoka S, Nakai S, Nishijima W, EMECS11-Sea Coasts XXVI Joint Conference, Russia, 2016
  16. Transfer efficiency from primary producers to Ruditapes philippinarum on an intertidal flat in Hiroshima Bay, Japan, Otani S, Umehara A, Miyagawa H, Asaoka S, Fujii N, Okuda T, Nakai S, Nishijima W, EMECS11-Sea Coasts XXVI Joint Conference, Russia, 2016
  17. Biological productivity on lower trophic levels in inter-tidal and sub-tidal areas in Hiroshima Bay, Japan, Umehara A, Asaoka S, Otani S, Fujii N, Miyagawa H, Nakai S, Okuda T, Ohno M, Nishijima W, The 3rd Asian Marine Biology Symposium, Kumamoto Japan, 2017
  18. A new index for assessing phytoplankton growth potential in the Seto Inland Sea, Japan, Wang F, Umehara A, Ohno M, Nishijima W, Nakai S, The 3rd Asian Marine Biology Symposium, Kumamoto Japan, 2017
  19. Pollution of the shore ecosystem with microcystins (hepatotoxic cyanotoxin) derived from freshwater cyanobacteria, Takahashi T, Umehara A, Tsutsumi H, Park HD, Jeon BS, The 3rd Asian Marine Biology Symposium, Kumamoto Japan, 2017
  20. Identifying sulfur species in marine sediments collected from Seto Inland Sea, Japan using XAFS, Asaoka S, Ushihara Y, Umehara A, Takeda K, Sakugawa H, Hayakawa S, The 22nd Hiroshima International Symposium on Synchrotron Radiation, Hiroshima Japan, 2018
  21. Evaluation of benthic quality using M-AMBI in Seto Inland Sea, Japan, Umehara A, Nakai S, Okuda T, Ohno M, Nishijima W, Estuarine and Coastal Science Association 57, Australia, 2018
  22. Evaluation of water purification function by eelgrass (Zostera marina) meadows and its application to coastal management, Umehara A, Otani S, Asaoka S, Fujii N, Miyagawa H, Sugimoto K, Uchida Y, Nakai S, Nishijima W, EMECS12-Cooperative stewardship for integrated management toward resilient coastal seas, Thailand, 2018
  23. Determination of region-specific background Secchi depth in four temperate semi-enclosed seas, central Japan, Wang F, Umehara A, Nishijima W, Nakai S, EMECS12-Cooperative stewardship for integrated management toward resilient coastal seas, Thailand, 2018
  24. Management of the ecosystem in the Seto inland sea, Nishijima W, Okuda T, Umehara A, Nakai S, Tada K, EMECS12-Cooperative stewardship for integrated management toward resilient coastal seas, Thailand, 2018
  25. The role of nutrient sink of Zostera marina on a benthic sandy tidal flat in Hiroshima Bay, Japan, Otani S, Umehara A, Asaoka S, Fujii N, Okuda T, Tsuji D, Miyagawa H, Nakai S, Nishijima W, EMECS12-Cooperative stewardship for integrated management toward resilient coastal seas, Thailand, 2018
  26. Concentrating Organic Matters in Sewage using Forward Osmosis Membrane Treatment for Energy Production by Methane Fermentation, Uchida H, Ohno M, Nishimoto S, Hashimoto K, Umehara A, Nakai S, Nishijima W, The Water and Environment Technology Conference, Ehime Japan, 2018
  27. Experimental wastewater recycling in Hiroshima University, Umehara A, MIRAI Short Course for PhD on Sustainability"Membranes for Sustainable Water Cycle", 2018, With Invitation
  28. Cyanotoxin risk assessment for management of water environment, Umehara A, Division of Environment, the Society of Chemical Engineers, Japan, Mini-symposium-Systems and Technologies for the Aquatic Environment Management in Asia, Hiroshima Japan, 2018, With Invitation
  29. Long-term changes in the benthic environment in the Seto Inland Sea, Umehara A, Borja Á, Nakai S, Nishijima W, The Fourth Asian Marine Biology Symposium, Taiwan, 2019
  30. Identification coastal zone vulunerable to phytoplankton growth in the Seto Inland Sea, Japan, Wang F, Umehara A, Nakai S, Nishijima W, 9th International Conference on Marine Pollution and Ecotoxicology, Hong Kong, 2019
  31. Cyanotoxin risk assessment for management of water environment. Division of Environment, Umehara A, the Society of Chemical Engineers, Japan, Mini-symposium-Systems and Technologies for the Aquatic Environment Management in Asia, 2018, With Invitation
  32. Experimental wastewater recycling in Hiroshima University, Umehara A, MIRAI Short Course for PhD on Sustainability Membranes for Sustainable Water Cycle, 2018, With Invitation
  33. Quantifying the contributions of various nutrient sources to amounts of N and P in the Eastern Seto Inland, Japan, towards the better nutrient management, Hamawaki R, Umehara A, Nishijima W, 9th IWA-ASPIRE Conference and Exhibition 2023, Taiwan

External Funds

Acceptance Results of Competitive Funds

  1. 2011
  2. 2012
  3. 2012
  4. 2013
  5. 2015
  6. 2019, 2021
  7. 2019
  8. 2019, 2021
  9. 2020
  10. 2021
  11. 2022, 2024

Social Activities

History as Committee Members

  1. Frontiers in Marine Science (Marine Ecosystem Ecology), Review Editor, 2021, 2024
  2. Plankton & Benthos Research (Japanese Association of Benthology), Editor, 2021, 2024