I am interested in phytoplankton in relation to carbon and nitrogen fluxes. During my Ph.D. program (in Marine Sciences, University of Gothenburg, Sweden), I studied diatoms, dinoflagellates and filamentous cyanobacteria, and measured small-scale nutrient fluxes down to the single-cell level using SIMS. We observed interesting interactions between diatoms and heterotrophic bacteria, which potentially enhanced the availability of ammonium for the diatoms up to four times compared to their theoretical diffusion limitation. We also hatched hundred year old diatoms to compare nutrient assimilation a century ago with today. Interestingly, the diatoms indicated a large variability at the single-cell level, larger than across a century, and we believe this might be one of many keys to their success in sustaining and spreading in the global ocean during changes in the environment. At UGA, I am working with Dr. Moran and colleagues to examine metabolites released from diatoms and assimilated by heterotrophic bacteria, during different growth stages and also under various climate change conditions (CO2, temperature and nutrients).