The Role of Zooplankton Grazers in Harmful Algal Blooms in the Santa Monica Bay, CA
Student: Ellen Dempsey
Advisor: Dr. Rebecca Shipe
Harmful Algal Blooms (HAB) are a growing global and local problem; toxins as well as decay of high cell abundances can be deleterious to birds, mammals, and even humans. Zooplankton are consumers of phytoplankton; most have feeding preferences and thus may contribute to the preferential growth of certain taxa. In this study, we hypothesize that zooplankton will graze preferentially on non-toxic species, allowing toxic species to bloom. Weekly abundances of zooplankton were determined at the Santa Monica pier near the SCCOOS monitoring station using a vertical net tow through the first meter of sea water. During the period of sampling we observed two periods of zooplankton abundance, a bloom of non harmful diatoms, and a bloom of harmful dinoflagellates. During the study, it is likely that environmental factors, such as water temperature and salinity, exert a greater control on HAB taxa abundance than zooplankton. The complicated relationship between zooplankton and harmful algae are important to understand as we try to predict the timing and composition of HABs.