A review of phytoplankton composition within Chesapeake Bay and its tidal estuaries

Based on a continuous 20-year data base of monthly sampling in Chesapeake Bay and tidal regions of its major tributaries, 1454 phytoplankton taxa have been identified in these waters. They represent a diverse assemblage of species with a dominant diatom flora throughout the year, in addition to large seasonal representation by chlorophytes, cyanobacteria, cryptophytes and dinoflagellates. Included among this flora were 34 potential harmful or toxin producing species. The phytoplankton compositions associated with the seasonal successional patterns are discussed, in addition to characterizing the dominant floral relationships, with comparison to early composition records within the Bay. Several of the present day most common taxa were similar to those reported in sediment cores from the Bay dating to periods prior to European settlement. Comparison with collections made ∼8 decades ago (1916-1922) within Chesapeake Bay indicated several of the same dominant flora remain dominant today; however, their cell concentrations are now significantly greater along with an increased diversity of species compared with these earlier studies.