It is known that the habitats of the common merganser and the freshwater snail Stagnicola emarginata, the two usual hosts required for Tricobilharzia stagnicolae to complete its life cycle, closely overlap. S. emarginata is also a host for Diplostomum flexicaudum, a parasite that infects the eyes of fish. This project attempts to find evidence that fish infected with D. flexicaudum are an important component of the diet of common merganser ducklings. Merganser foraging data was collected by surveying Douglas Lake, MI and recording where birds are found and when they are observed diving. Fish were collected with minnow traps at sites around the lake and the eyes were dissected for determination of incidence and prevalence of infection. Foraging activity and fish infection rates will be correlated for different sites.