Toshi Nagata (Professor)


Prof. Toshi Nagata (Marine Biogeochemistry Group)

My research interests cover a broad range of topics in marine biogeochemistry and ecology. Current research themes include organic matter-microbe interactions in marine environments. This research investigates how microbes degrade and transform organic matter to affect carbon and nitrogen cycles in marine systems. I am also interested in the application of isotope methods to investigate the ecology of marine organisms and biogeochemical processes. This includes exploring the application of radiocarbon and compound specific isotope ratios as natural tracers of marine organismal growth, migration, and diet histories. The overall goal is to contribute to a better understanding of mechanisms by which marine ecosystems respond to regional and global environmental changes. See the project page for more details.


I completed my Master and Doctor’s degrees in limnology (zoology) at Kyoto University, before joining Dave Kirchman’s lab at University of Delaware as a postdoc, and subsequently serving on the faculty of Nagoya University, Kyoto University and The University of Tokyo. I currently serve as responsible editor for following journals. Frontiers in Marine Science; Marine Ecology Progress Series; Fundamental and Applied Limnology

(Full CV)

For those who are interested in joining us

We have an international research group with graduate students and postdoctoral researchers. If you are interested in joining us please send me e-mail describing your specific scientific interests, motivation, and reason why you are interested in joining us. It is also preferable to provide names of potential referees. You are urged to seek external financial support. I might not respond to each of the general message with insufficient information. I have previously advised one foreign student and 5 JSPS postdoctoral fellows from various countries including Korea, China, India, Canada and Australia. I am currently affiliated with the graduate programs of Department of Biological Sciences, Graduate School of Science and Department of Integrated Biosciences, Graduate School of Frontier Science .

Selected publications

(First authors are current or previous students/postdocs)

Whole Publication List

Uchimiya, C. Motegi, S. Nishino, Y. Kawaguchi, J. Inoue, H. Ogawa, and T. Nagata (2016) Coupled response of bacterial production to a wind-induced fall phytoplankton bloom and sediment resuspension in the Chukchi Sea Shelf, Western Arctic Ocean. Frontiers in Marine Science-Marine Biogeochemistry | doi: 10.3389/fmars.2016.00231

Yamada Y., Fukuda H., Tada Y., Kogure K. and Nagata T. (2016) Bacterial enhancement of gel particle coagulation in seawater. Aquatic Microbial Ecology, 77: 11-22. doi: 10.3354/ame01784

Takasu, H. and Nagata T. (2015) High proline content of bacteria-sized particles in the western North Pacific and its potential as a new biogeochemical indicator of organic matter diagenesis. Frontiers in Marine Science, doi: 10.3389/fmars.2015.00110  <Open Access>

Yamada, Y., Fukuda,H., Uchimiya, M., Motegi, C., Nishino, S., Kikuchi, T., and Nagata, T. (2015) Localized accumulation and a shelf-basin gradient of particles in the Chukchi Sea and Canada Basin, western Arctic. Journal of Geophysical Research: Oceans, 120, doi:10.1002/2015JC010794 <Open Access>

Uchimiya, M., H. Ogawa and T. Nagata (2015) Effects of temperature-elevation and glucose-addition on prokaryotic production and respiration in the mesopelagic layer of the western North Pacific. Journal of Oceanography, DOI10.1007/s10872-015-0294-4

Yang, Y., Yokokawa, T., Motegi, C., and Nagata, T. (2014) Large-scale distribution of viruses in deep waters of the Pacific and Southern Oceans. Aquatic Microbial Ecology, 71: 193-202. Doi: 10.3354/ame01677 (FEATURE ARTICLE) <Open Access>

Maki, K., Ohkouchi, N., Chikaraishi, Y., Fukuda, H., Miyajima, T. and Nagata, T. (2014) Influence of nitrogen substrates and substrate C:N ratios on the nitrogen isotopic composition of amino acids from the marine bacterium Vibrio harveyi. Geochimica et Cosmochimica Acta, 140: 521-530. DOI:10.1016/j.gca.2014.05.052 <Open Access>

Motegi, C., Nagata, T., Miki, T., Weinbauer, M.G., Legendre, L., and Rassoulzadegan, F. (2013) Interactive effects of viral and bacterial production on marine bacterial diversity. PLoS ONE 8(11): e76800.doi:10.1371/journal.pone. 0076800 <Open Access>

Thibodeau, B., Miyajima, T., Tayasu, I., Wyatt, A.S.J., Watanabe, A., Morimoto, M., Yoshimizu, C., and Nagata, T. (2013) Heterogeneous dissolved organic nitrogen supply over a coral reel: first evidence from nitrogen stable isotope ratios. Coral Reefs, DOI 10.1007/s00338-1070-9

Yokokawa, T., Yang, Y., Motegi, C. and Nagata, T. (2013) Large-scale geographical variation in prokaryotic abundance and production in meso- and bathypelagic zones of the central Pacific and Southern Ocean. Limnology and Oceanography. 58(1): 61–73 <Open Access>