Romberg Tiburon Center for Environmental Studies

Image: Ripples on water

SF State's bayside marine and estuarine research facility.

William Cochlan - Senior Research Scientist

Marine Microbial Ecology and Oceanography
Romberg Tiburon Center and Department of Biology

Phone:(415) 338-3541
Website: lab website

Bill Cochlan

Research Interests

I am a biological oceanographer/marine microbial ecologist who addresses the fundamental question: "What environmental factors control phytoplankton growth, their nutrition, and distribution in the ocean?" More specifically, how do the multiple interactions of light, macro- and micro-nutrients, and ocean acidity affect the physiology of marine phytoplankton and bacteria, and hence determine their growth rates, biochemical content and activities, and distribution patterns in the sea from coastal to oceanic environments.


My laboratory has been studying phytoplankton in unialgal cultures and during field studies ranging from polar to equatorial waters. Recently, much of our efforts have been directed towards the study of toxic microalgae that form Harmful Algal Blooms (HABs) both locally in San Francisco Bay, adjacent coastal waters, and the Pacific Northwest, including Puget Sound, WA. We also study how ocean acidification affects the nutritional content of coastal phytoplankton found in the upwelling regions of the West Coast.


In addition to studying both harmful and benign phytoplankton, we are involved in research to generate biofuels from lipogenic phytoplankton. Our research efforts support the development and optimization of the commercial technology for this emerging industry.


Selected Papers

Auro, M.E., and W.P. Cochlan. 2013. Nitrogen utlization and toxin production by two diatoms of the Pseudo-nitzschia pseudodelicatissima complex: P. cuspidata and P. fryxelliana. J. Phycology DOI: 10.111/jpy.12033.


Trainer, V.L., S.S. Bates, N. Lundholm, A.E. Thessen, W.P. Cochlan, N.G. Adams, and C.G. Trick. 2012. Pseudo-nitzschia physiological ecology, phylogeny, toxicity, monitoring and impacts on ecosystem health. Harmful Algae 14: 271-300.


Kudela, R.M., S. Seeyave, and W.P. Cochlan. 2010. The role of nutrients in regulation and promotion of harmful algal blooms in upwelling systems. Progr. Oceanogr. 85: 122-135.


Trick, C.G., B. Bill, W.P. Cochlan, M.L. Wells, V.L. Trainer, and L.D. Pickell. 2010. Iron enrichment stimulates toxic diatom production in High Nitrate, Low Chlorophyll areas. Proc. Nat. Acad. Sci. 107: 5887-5892.


Kudo, I., Y. Noiri, W.P. Cochlan, K. Suzuki, T. Aramaki, T. Ono, and Y. Nojiri. 2009.Primary productivity, bacterial productivity and nitrogen uptake in response to iron enrichment assimilation during the SEEDS II. Deep-Sea Res. II 56: 2755-2766.


Pickell, L.D., M.L. Wells, C.G. Trick and W.P. Cochlan. 2009. A sea-going continuous culture system for investigating phytoplankton community response to macro- and micro-nutrient manipulations. Limnol. Oceanogr. Methods 7: 21-32.


Trainer, V.L., M.L. Wells, W.P. Cochlan, C.G. Trick, B.D. Bill, K.A. Baugh, B. F. Beall, J.Herndon, and N. Lundholm. 2009. An ecological study of a massive bloom of toxigenic Pseudo-nitzschia cuspidata off the Washington State coast. Limnol. Oceanogr. 54: 1461-1474.


Wells, M.L., C.G. Trick, W.P. Cochlan, and B. Beall. 2009. Persistence of iron limitation in the western subarctic Pacific SEEDS II mesoscale fertilization experiment. Deep-Sea Res. II 56: 2810-2821.


Cochlan, W.P. 2008. Nitrogen Uptake in the Southern Ocean. In: Nitrogen in the Marine Environment, 2nd Edition, D.G. Capone, D.A. Bronk, M.R. Mulholland, and E.J. Carpenter [Eds.]. Academic Press, Elsevier, pp. 569-596.


Cochlan, W.P., J. Herndon, and R.M. Kudela. 2008. Inorganic and organic nitrogen uptake by the toxigenic diatom Pseudo-nitzschia australis). Harmful Algae 8: 111-118.


Kudela, R.M., J.Q. Lane, and W.P. Cochlan. 2008. The potential role of anthropogenically derived nitrogen in the growth of harmful algae in California, USA. Harmful Algae 8: 103-110.


Herndon, J., and W.P. Cochlan. 2007. Nitrogen utilization by the raphidophyte Heterosigma akashiwo: growth and uptake kinetics in laboratory cultures. Harmful Algae 6: 260-270.


Coale, K.H., et al., (including W.P. Cochlan) 2004. Southern Ocean Iron Enrichment Experiment: Carbon Cycling in High- and Low-Si Waters. Science 304: 408-414.


Cochlan, W.P., and D.A. Bronk. 2003. Effects of ammonium on nitrate utilization in the Ross Sea: Implications for ƒ-ratio estimates. In: DiTullio, G.R, Dunbar, R.B. [Eds.], Biogeochemistry of the Ross Sea. AGU Antarctic Research Series 78: 159-178.


Cochlan, W.P., D.A. Bronk, and K.H. Coale. 2002. Trace metals and nitrogenous nutrition of Antarctic phytoplankton: experimental observations in the Ross Sea. Deep-Sea Res. II 49: 3365-3390.


Cochlan, W.P. 2001. The heterotrophic bacterial response during a mesoscale iron enrichment experiment (Iron Ex II) in the eastern equatorial Pacific Ocean. Limnol. Oceanogr. 46: 428-435.


Cochlan, W.P., and D.A. Bronk. 2001. Nitrogen uptake kinetics in the Ross Sea, Antarctica. Deep-Sea Res. II 48: 4127-4153.


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