Nicolas Cassar

Nicolas Cassar

Associate Professor of Biogeochemistry

Primary Appointment

Earth & Ocean Sciences Division

Nicolas Cassar's research focuses on environmental biogeochemistry and physiology, with the objective of constraining the mechanisms governing carbon cycling and climate. Current research interests include ocean carbon cycles and productivity; carbon acquisition mechanisms in marine phytoplankton and implications for climate change and paleo-CO2 reconstruction; and global carbon cycle and ocean-atmosphere fluxes. His scientific approach is interdisciplinary, integrating field observations, laboratory experiments, modeling and theory.

In The News


Lin, Yajuan, Scott Gifford, Hugh Ducklow, Oscar Schofield, and Nicolas Cassar. “Towards Quantitative Microbiome Community Profiling Using Internal Standards..” Applied and Environmental Microbiology 85, no. 5 (March 2019).
Tang, W., Z. Li, and N. Cassar. “Machine Learning Estimates of Global Marine Nitrogen Fixation.” Journal of Geophysical Research: Biogeosciences 124, no. 3 (March 1, 2019): 717–30.
Berthelot, Hugo, Solange Duhamel, Stéphane L’Helguen, Jean-Francois Maguer, Seaver Wang, Ivona Cetinić, and Nicolas Cassar. “NanoSIMS single cell analyses reveal the contrasting nitrogen sources for small phytoplankton..” The Isme Journal 13, no. 3 (March 2019): 651–62.
Tang, Weiyi, Seaver Wang, Debany Fonseca-Batista, Frank Dehairs, Scott Gifford, Aridane G. Gonzalez, Morgane Gallinari, Hélène Planquette, Géraldine Sarthou, and Nicolas Cassar. “Revisiting the distribution of oceanic N2 fixation and estimating diazotrophic contribution to marine production..” Nature Communications 10, no. 1 (February 19, 2019).
Li, Z., and N. Cassar. “Theoretical Considerations on Factors Confounding the Interpretation of the Oceanic Carbon Export Ratio.” Global Biogeochemical Cycles 32, no. 11 (November 1, 2018): 1644–58.

Recent Grants


EOS 364S: Changing Oceans (EOS 364S: Changing Oceans)
EOS 394: Research Independent Study (EOS 394: Research Independent Study)
EOS 791: Independent Study (EOS 791: Independent Study)
EOS 525: Fundamentals of Water Biogeochemistry and Pollution (EOS 525: Fundamentals of Water Biogeochemistry and Pollution)
EOS 393: Research Independent Study (EOS 393: Research Independent Study)

Video: Wang recalls NASA research cruise


Contact Information

Box 90328
Durham, NC 27708
Grainger Hall, 9 Circuit Drive (Eh5118), Nicholas School of the Environment
Durham, NC 27708


Ph.D., University of Hawaii at Manoa (2003)
B.S., McGill University (Canada) (1997)