Larval lake whitefish diets in western Lake Erie during 2018, 2019, and 2021

Recent declines in Lake Whitefish population abundance has prompted research to identify underlying mechanisms controlling survival of early life stages in the Great Lakes. In Lake Erie, the recruitment bottleneck window determining year class strength of Lake Whitefish occurs during the first growing season, suggesting that availability of prey could be controlling year class strength. Therefore, spatial and seasonal larval Lake Whitefish distribution, diet, and environmental zooplankton (potential prey) were collected to evaluate larval Lake Whitefish diets at 31 locations in the western basin during 2017, 2018, and 2021. We removed gut tracks of larval lake whitefish and identified diet items to lowest possible taxon. Zooplankton samples were taken in the field and identified in the lab. Zooplankton were identified to the taxonomic level of large cladoceran, small cladoceran, cyclopoid copepods, calanoid copepods, nauplii, and rotifer. Diet item body length was measured for the first 20 individuals of each prey item in each sample.