Filter feeding bivalves exposed to the harmful algal bloom (HAB) genus, Dinophysis, become intoxicated by the uptake of diarrhetic shellfish toxins (DSTs) produced by these phytoplankton. Here, three species of bivalve (Crassostrea virginica, Mercenaria mercenaria, and Mytilus edulis) native to the western North Atlantic were exposed to two North American strains of toxigenic Dinophysis acuminata to assess the impacts of cell density, cell density as a fraction of the total plankton community, and differing Dinophysis prey (i.e. strains of the ciliate, Mesodinium rubrum) on bivalve clearance rates. All bivalves cleared D. acuminata faster when the dinoflagellate was offered at moderate densities (10,000 cells L