Seminar: Monday, April 15, 2024

Dr. Marchetti is an Associate Professor in the Earth, Marine, and Environmental Sciences Department at University of North Carolina at Chapel Hill. The Marchetti Lab combines physiological and molecular approaches in laboratory isolates and natural communities to investigate how plankton are affected by their environment and in turn, influence ocean biogeochemistry and ecosystem dynamics. Particular interests include studying trace metals, such as iron, that are essential for the nutrition of phytoplankton and microzooplankton and predicting the effects of future climate changes on plankton distribution and abundance. A description of the talk to be given on Monday is below. 

Exploring the many facets of marine phytoplankton: from proton-pumping rhodopsins to community dynamics in response to upwelling

Phytoplankton are responsible for roughly half of global primary productivity and are at the base of most marine food webs. Learning the strategies phytoplankton invoke to cope with certain environmental conditions is critical to our understanding of what influences their distribution and abundance as well as their impact on ocean biogeochemistry. In this talk, I will present two recent studies conducted in my lab demonstrating how phytoplankton have evolved to their distinct ocean environments. First, recently identified, vacuolar-localized proton pumping rhodopsins in polar diatoms may be critical to their survival in cold, low-iron and variable light regions of the ocean. Second, shifts in community composition and physiology under dynamic coastal upwelling conditions demonstrate how the metabolic strategies of distinct phytoplankton groups contribute to their success. These studies highlight how implementing a multi-pronged approach in both natural assemblages and laboratory isolates enables us to determine how phytoplankton may be affected by both current and future ocean conditions.