Zebra mussel (Dreissena polymorpha) effects on sediment, other zoobenthos, and the diet and growth of adult yellow perch (Perca flavescens) in pond enclosures

Abstract

Zebra mussels (Dreissena polymorpha) in enclosures located in an experimental pond adjacent to Lake St. Clair, Michigan, increased sedimentation rate but had relatively minor effects on percent organic matter and percent nitrogen content of sediment. In contrast, sediment from Lake St. Clair adjacent to zebra mussels was significantly higher in carbon than that 0.5 m away. Zebra mussels increase the nutritional value of surficial sediment and provide greater structural heterogeneity, which is probably more important in causing change among zoobenthos. Zoobenthos and yellow perch (Perca flavescens) diet were dominated by dipteran larvae and leeches. Zoobenthos was significantly different between enclosures with and without zebra mussels. Treatments with zebra mussels had significantly more oligochaetes and tended to have more crustaceans (isopods and amphipods). In June, yellow perch without zebra mussels consumed significantly more zooplankton, and those with mussels had more crustaceans in their diet. Zooplankton density was greater in treatments without zebra mussels. Yellow perch with zebra mussels grew significantly more than those without mussels. Zebra mussels in the enclosures neither reproduced nor were eaten by yellow perch; hence. the observed growth differences were due to indirect effects involving zebra mussel induced changes in benthic structure and biota.