Zooplankton are microscopic organisms that inhabit lakes and serve as a link between the primary producers (phytoplankton) and the top predators (fish). The community structure and abundance of these organisms reflect the true nature of environmental change and disturbance. Using these organisms, we have examined the impacts of eutrophication, climate change, and invasive species. With respect to invasive species we have documented a shift in species composition as the result of the introduction of spiny water fleas in Lake George. To fully investigate this phenomenon, we identified the diet of Spiny water fleas using a molecular biology approach.