Parasites play an important role in natural systems such as lakes, but are often understudied compared to other ecological changes that occur in these systems over time. Our project summarized here demonstrates the value of parasites as indicators. During our research on the parasites of the fishes of Oneida lake and its tributaries we found evidence of parasite disappearance and the arrival of previously unreported species. Our project resulted in 2 completed publications and 2 more in preparation. Other outcomes included the training of 7 students and the engagement of area schoolchildren in a hands-on parasite workshop.