Massive, months-long blooms of the dinoflagellate,
Cochlodinium polykrikoides, have occurred throughout lower Chesapeake
Bay and its tributaries in most of the last 20+ years. Based on long-term,
high-frequency monitoring, we have identified hotspots for bloom initiation
in the Lafayette and Elizabeth Rivers, sub-tributaries of the lower
Chesapeake Bay. There are interannual differences in the timing, magnitude
and duration of blooms and these appear to be related to interannual
differences in the timing of increases in water temperature and physical
processes that dominate tidal estuaries. While specific ranges of
temperature and salinity properties appear to be necessary, they are not
sufficient for bloom development. Because C. polykrikoides make
cysts residing in the sediments, sediment resuspension is an important
precursor to bloom formation. Little is known about the life cycle of
C. polykrikoides and the environmental factors necessary for
successful excystment. Bloom initiation has been linked locally with
sediment and nutrient resuspension, stratification, and estuarine
circulation as modulated by spring-neap tidal cycles and meteorological
pertubations. Once initiated, mixotrophic C. polykrikoides
populations can meet their nutritional needs in a variety of ways. Vertical
migration may facilitate their acquisition of nutrients and may allow them
to avoid predation.
Dr. Mulholland received a B.S. in Geology and Biology from the University of Notre Dame. She earned a M.S. in Biological Oceanography and a M.M.A. in Marine Affairs (Policy), both from the University of Washington. Her Ph.D. in Oceanography came from the University of Maryland's Chesapeake Biological Laboratory. Dr. Mulholland has had visiting appointments in the Philippines and Japan, served as a Peace Corps volunteer, and was a postdoc and research assistant professor at the State University of New York, Stony Brook. Presently, she is a professor in the Department of Ocean, Earth and Atmospheric Sciences at Old Dominion University.
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