The goal of this project is to examine the dynamics of Margalefidinium polykrikoides (formerly Cochlodinium polykrikoides) blooms in the Lafayette River, a sub-tributary of the lower Chesapeake Bay and to establish relationships between surface water chlorophyll concentrations and dinoflagellate abundance throughout the water column. M. polykrikoides blooms nearly annually in the late summer in the lower James River where it can cause severe water quality impairments. Complicating bloom detection is the behavior of these mixotrophic dinoflagellates; in addition to their distribution being patchy in surface waters, they also undertake daily vertical migrations. Cells migrate into bottom waters at night, possibly to acquire nutrients, and return to the surface during the day, possibly to acquire light for photosynthesis. The motivation for this study is to better understand these vertical migrations in order to develop a better assessment tool to evaluate water quality impairments in the Lower James River watershed.
