Spatial and Temporal Variability of Phytoplankton and Zooplankton in Western Lake Erie

We examined the plankton communities within western Lake Erie during the summers of 1995 and 1996 and evaluated the hypothesis that zebra mussels exert strong control over the abundance and spatial distribution of plankton. Phytoplankton and zooplankton biomass exhibited strong seasonal and spatial variability throughout the summers of 1995 and 1996. Nearshore areas generally contained more phytoplankton and zooplankton biomass than the offshore sampling area, but there was wide variability in pelagic phytoplankton and crustacean zooplankton. Zooplankton taxonomic composition was different between sampled areas, with more calanoid copepods compared to cladocerans and cyclopoid copepods found in deep, offshore stations. Such patterns increase the difficulty in understanding the effects of zebra mussels on western Lake Erie as they suggest that additional factors, such as nutrient availability, also affect the biomass of these pelagic communities.