IntroductionOysters play a critical role in the aquatic nitrogen (N) andphosphorus (P) cycles through benthic–pelagic coupling processes(Newell et al., 2005). The Eastern Oyster, Crassostrea virginica,is a suspension-feeding bivalve, meaning it filters suspendedparticles from the water column, preferentially ingesting somewhile rejecting others as pseudofeces (Galtsoff, 1964; Haven andMorales-Alamo, 1970; Newell and Jordan, 1983; Ward et al., 1994).The main processes to be considered when discussing the role of C.virginica in the N and P cycles are: the filtration of suspended mat-ter including phytoplankton; the process of feces and pseudofecesdeposition; excretion of N and P by the oysters; and the incorpora-tion of N and P into the oyster shell and tissue (Fig. 1). This study isfocused on filtration of phytoplankton and excretion of N and P.