Yamashita Lab

Graduate School of Environmental Science, Hokkaido University


Youhei Yamashita (PhD)

Associate Professor


Faculty of Environmental Earth Science,

Hokkaido University

N10, W5, Kita-ku, Sapporo, Hokkaido 060-0810, Japan

Tel: +81(11)-706-2349

E-mail: yamashiy at ees.hokudai.ac.jp



[Research keywords]

Biogeochemistry, Carbon Cycle, Oceanography, Limnology, Land-Ocean Interface, Dissolved Organic Matter, Bioavailability, Refractory



[Research interest]

Dissolved organic matter (DOM) is an important component of the global carbon cycle and represents one of the largest carbon pools on the Earth’s surface. It plays an important role in the biogeochemical cycles, and knowledge of its environmental dynamics in aquatic environments is essential for a better understanding of ecosystem function and carbon cycling. Our group uses quantitative and qualitative approaches, especially optical means, for the characterization of DOM and to assess its environmental dynamics.



[Current lab member]

Youhei Yamashita (Associate Professor)

Fumi Sakai (Lab Technician)

Yuji Takaki (D1)

Yusuke Ooshima (M2)

Riku Miyase (M1)

Haruka Kubo (B4)



[Selected publications]


Yamashita, Y., Y. Mori, and H. Ogawa (2023) FHydrothermal-derived black carbon as a source of recalcitrant dissolved organic carbon in the ocean, 9, eade3807.

Yamashita, Y., M. Nakane, Y. Mori, J. Nishioka, and H. Ogawa (2022) Fate of dissolved black carbon in the deep Pacific Ocean. Nature Communication, 13, 307.

Yamashita, Y., J. Nishioka, H. Obata and H. Ogawa (2020) Shelf humic substances as carriers for basin-scale iron transport in the North Pacific. Scientific Reports 10: 4505.

Goto, S., Y. Tada, K. Suzuki, and Y. Yamashita (2017) Production and reutilization of fluorescent dissolved organic matter by a marine bacterial strain, Alteromonas macleodii. Frontiers in Microbiology, 8, 507.

Yamashita, Y., N. Maie, H. Briceño and R. Jaffé (2010) Optical characterization of dissolved organic matter in tropical rivers of the Guayana Shield, Venezuela. Journal of Geophysical Research 105: G00F10.


Yamashita, Y. and R. Jaffé (2008) Characterizing the interactions between trace metal and dissolved organic matter using excitation-emission matrix and parallel factor analysis. Environmental Science and Technology 42: 7374-7379.


Yamashita, Y. and E. Tanoue (2008) Production of bio-refractory fluorescent dissolved organic matter in the ocean interior. Nature Geoscience 1: 579-582.


Yamashita, Y., R. Jaffé, N. Maie and E. Tanoue (2008) Assessing the dynamics of dissolved organic matter (DOM) in coastal environments by excitation emission matrix fluorescence and parallel factor analysis (EEM-PARAFAC). Limnology and Oceanography 53: 1900-1908.


Graduate School of Environmental Science, Hokkaido Universityhttps://www.ees.hokudai.ac.jp/