My research focuses on the distribution, activity and diversity of marine microorganisms and their overall roles in ecosystem function. I am very interested in planktonic (open ocean) symbioses between cyanobacterial partners and a variety of single celled eukaryotic hosts (Diatoms, Dinoflagellates, Tintinnids, Radiolarians). We know that nitrogen, carbon, and other nutrients (i.e. phosphorus, iron, vitamins) are exchanged between organisms but we know very little about how that exchange occurs or is regulated between the individual partners of marine symbioses. Using various research tools and methodologies I try to gain insights into their patterns of distribution, activity, and the metabolic interactions of the hosts and symbiotic partners. These symbioses are important to both Nitrogen and Carbon cycles in the world’s oceans and my goal is to unveil their biogeochemical significance and evolutionary importance. I am also interested in the variability of carbon and nitrogen assimilation in other phytoplankton populations and how life history strategies (colonial vs. free-living) influence their metabolism, growth and competition in the environment. What excites me most about my research is that it crosses several ecological scales. On a micro-scale, I identify the metabolic exchanges, diversity, and distribution of individual cells, while on a larger scale, I determine the contributions of these populations to biogeochemical cycling in the world’s oceans.