Diatoms' Response to Quantified Turbulent Environments

Diatoms play important roles in the health of ocean ecosystems and carbon and nutrient cycling. These unicellular phytoplankton absorb CO₂ and begin its transport from the atmosphere to the deep ocean through sinking. Diatoms likely sink to regulate a balance between sunlight absorption and access to nutrient uptake in the water. Previous studies of sinking behavior have shown that variables in their natural habitat affect diatoms’ sinking behavior, suggesting cells have the ability to respond to the environment around them. This study investigates the response of the diatom Coscinodiscus to different turbulent conditions to increase understanding of diatom behavior. Treatments mimic four natural environments: surf, inlet/estuaries, continental shelf, and open ocean. We will utilize a variety of methods adapted from studies that replicated natural turbulence to observe effects of hydrodynamic forces. Additionally, this study will build on previous research that identified significant differences in diatom sinking behavior after uncharacterized turbulence. Quantifying turbulence using dissipation rate and acceleration is essential to apply these results to larger oceanographic models and to better understand diatom sinking in the greater context of marine ecosystems.