Other studies in this area are on the diversity and interactions of surface ocean microbes – including algae and their predators as well as other entities, such predators and their symbionts and viruses. This area is led by Alexandra Worden with participation from several team members, including Camille Poirier (now at Oxford), Susanne Wilken (now a Professor in Amsterdam), Kristin Bergauer (now a group lead at GEOMAR) and on the analysis side David Needham (now a Junior Professor at University of Kiel). We use multiple approaches, including Stable Isotope Probing (SIP) and at sea single-eukaryote cell sorting to tease apart interactions between protists and other biological entities in the sea. Sorting is followed by DNA sequencing and, from there, characterization of genomes, protein functions and transcriptional activities in the field (Fig. 3). In collaboration with the Alm Lab at MIT we are developing additional approaches as well. Some of our work in this area can be seen at Needham et al. PNAS 2019, Needham et al Proceedings of the Royal Academy B. Understanding interactions is important for then being able to predict the fate of fixed carbon – does it end up being exported into the deep sea, or is it respired while still in the surface ocean?