INVESTIGATIONS OF THE EFFECTS OF OYSTER ALLOMETRY AND REEF MORPHOLOGY ON FILTRATION RATE AND PARTICLE CAPTURE USING NUMERICAL MODELS

Abstract

Crassostrea virginica, the eastern oyster, is a filter-feeding, particle clearing bivalve currently at low numbers in Chesapeake Bay. Accurately describing the filtration rate of these bivalves is essential to estuarine management and associated efforts to understand the impact of oyster populations on water quality. Here, the filtration rate equations for three existing models (Cerco and Noel (2005), Fulford et al. (2007), and Powell et al. (1992)) are assessed. I examine how each of the models define the maximum filtration rate and explore the various limitation factors that modify these maximum rates via environmental conditions that include salinity, temperature, total suspended solids, and dissolved oxygen. Based on the individual model strengths found in the model comparison and a literature review, I determine a maximum filtration rate of 0.17 m3 g-1 DW day-1 for a 1 g DW oyster to be a better filtration rate, which is then modified by a combination of limitation factors taken from a variety of sources. These include those described by Fulford et al. (2007) for total suspended solids and salinity, and a newly developed function to describe temperature dependence. Differences in size are incorporated by using a basic allometric formulation where a weight exponent alters filtration rate based on individual oyster size.