Marine phytoplankton form the base of marine food webs and contribute half of the primary production on the planet. These diverse and remarkable microorganisms are in constant dialogue with their surroundings, responding to fluctuating resource availability (i.e. nutrients and light), neighboring microbiota and predation pressure from viruses and grazers over spatial and temporal scales. In our lab, we explore how phytoplankton live and die in these dynamic environments with the goal of advancing our understanding of biogeochemical cycling in the global ocean.