Simulated Upwelling for Diatom Isolates

We simulated the Upwelling Conveyor Belt Cycle (UCBC) in the laboratory for the diatom isolates Pseudo-nitzschia fryxelliania and Chaetoceros decipiens. By subjecting the isolate cultures to respective macronutrient starvation (N for P. fryxelliania, Si for C. decipiens) under Fe-replete or Fe-limited conditions, we aimed to understand how different pennate and centric diatom species acclimate and respond to the UCBC in relation to nutrient status. These experiments will provide us further insight into the molecular and physiological changes that occur within diatoms at different time points of the upwelling cycle, allowing us to examine both the metabolic processes and elemental stoichiometry at a finer scale. Ultimately, this study will can help us better comprehend how diatoms - the most dominant phytoplankton group during upwelling season in the California Current System - can influence carbon export efficiency and broader biogeochemical cycles.