The filtering rates of the Zebra Mussel, Dreissena polymorpha, as it relates to colonization density.

Abstract

Filtering rates of the zebra mussel, Dreissena polymorpha, were examined at the University of Michigan Biological Station in Pellston, MI. The study was conducted in order to determine if zebra mussel densities affect their ability to filter phytoplankton from the water. We also examined whether the relationship between organism density and filtering rate was linear or curvilinear. Finally, we determined the density in which maximum filtering rates were obtained. The filtering rates increased from the 0.5/cm2 to 1.5/cm2 density samples and tapered off for the higher density samples (2/cm2 and 4/cm2). This relationship is curvilinear since the filtering rates does not increase linearly with increasing density. The maximum filtering rate obtained by this population of zebra mussels occurs between the 1/cm2 and 1.5/cm2 densities. Thus, the density of organisms affects the filtering ability of the zebra mussel.