Sallie Watson Chisholm
|Born||1947 (age 72–73)|
Marquette, Michigan, U.S.
|Alma mater||Skidmore College|
University at Albany, SUNY
|Known for||Study of phytoplankton, especially Prochlorococcus|
|Awards||National Medal of Science|
Alexander Agassiz Medal (2010)
Crafoord Prize (2019)
|Institutions||Massachusetts Institute of Technology|
Early life and education
Chisholm has been a faculty member at the Massachusetts Institute of Technology since 1976. Her research has focused on the ecology of marine phytoplankton. Chisholm's early work focused on the processes by which such plankton take up nutrients and the manner in which this affects their life cycle on diurnal time scales. This led her to begin using flow cytometry which can be used to measure the properties of individual cells.
The application of flow cytometry to environmental samples led Chisholm and her collaborators (most notably R.J. Olson and H.M. Sosik) to the discovery that small plankton (in particular Prochlorococcus and Synechococcus) accounted for a much more substantial part of marine productivity than had previously been realized. Previously, biological oceanographers had focused on silicaceous diatoms as being the most important phytoplankton, accounting for 10-20 gigatons of carbon uptake each year. Chisholm's work showed that an even larger amount of carbon was cycled through these small algae, which may also play an important role in the global nitrogen cycle.
Honors and awards
In January 2010, she was awarded the Alexander Agassiz Medal, for "pioneering studies of the dominant photosynthetic organisms in the sea and for integrating her results into a new understanding of the global ocean." 
She was a co-recipient in 2012 of the Ruth Patrick Award from the Association for the Sciences of Limnology and Oceanography.
In 2019 she received the Crafoord Prize in Biosciences, “for the discovery and pioneering studies of the most abundant photosynthesising organism on Earth, Prochlorococcus”. This prize is considered equivalent to the Nobel Prize (for which there is no Biosciences category). Chisholm was honored at the Crafoord Prize Symposium in Biosciences at which 6 internationally prominent scientists spoke (in order of presentations): Alexandra Worden (GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany), Corina Brussaard (NIOZ Royal Netherlands Institute for Sea Research, The Netherlands), Ramunas Stepanauskas (Bigelow Laboratory for Ocean Sciences, USA), Rachel Foster (Stockholm University, Sweden), Francis M. Martin (INRA French National Institute for Agricultural Research, France) and David Karl (University of Hawaii, USA).
- Chisholm, S.W. 2012. Unveiling Prochlorococcus: The Life and times of the ocean’s smallest photosynthetic cell. 2012. In: Microbes and Evolution: The World That Darwin Never Saw. In: R. Kolter and S. Maloy [eds]. ASM Press. p. 165.
- Coleman, M. L.; Chisholm, S. W. (2010). "Ecosystem-specific selection pressures revealed by comparative population genomics". PNAS. 107 (43): 18634–18639. doi:10.1073/pnas.1009480107. PMC 2972931. PMID 20937887.
- Lindell, D.; Jaffe, J.D.; Coleman, M.L.; Axmann, I.M.; Rector, T.; Kettler, G.; Sullivan, M.B.; Steen, R.; Hess, W.R.; Church, G.M.; Chisholm, S. W. (2007). "Genome-wide expression dynamics of a marine virus and host reveal features of coevolution". Nature. 449 (7158): 83–86. doi:10.1038/nature06130. PMID 17805294.
- Chisholm, S.W.; Falkowski, P.G.; Cullen, J.J. "Dis-Crediting Ocean Fertilization". Science. 294 (309–310): 2001.
- Chisholm, S.W.; Olson, R.J.; Zettler, E.R.; Goericke, R.; Waterbury, J.; Welschmeyer, N. (1988). "A novel free-living prochlorophyte abundant in the oceanic euphotic zone". Nature. 334 (6180): 340–343. doi:10.1038/334340a0.
- "National Medalist". The Mining Journal. 2013-02-09. Retrieved 2013-03-09.
- "Sallie (Penny) Chisholm awarded the National Medal of Science, the nation's highest honor for scientists". MIT. 2013-02-19. Retrieved 2013-03-09.
- Strong, Aaron; Chisholm, Sallie; Miller, Charles; Cullen, John (2009-09-17). "Ocean fertilization: time to move on". Nature. 461 (7262): 347–348. doi:10.1038/461347a. PMID 19759603.
- "Academy Honors 17 for Major Contributions to Science". Office of News and Public Information, The National Academies. Retrieved 2010-01-20.
- "Scientific forum on oceans and climate with the participation of Sallie W. Chisholm, Ramon Margalef Prize in Ecology 2013". Universitat de Barcelona. Retrieved 2013-10-25.
- Crafoord Prize 2019