Walleye (Sander vitreus) are an ecologically and economically significant fish harvestedby recreational and commercial fisheries across Ontario. Adult Walleye are piscivores, but anecdotal evidence from anglers suggests that Walleye often target aquatic insects such as mayfly larvae (Ephemeroptera). My research examined the diet of Walleye caught from May to September in Lake St. Joseph in northern Ontario. I examined the stomach contents of angle harvested Walleye to identify the prey over two summers. Through morphological analysis of stomach contents, mayflies were found to be a significant prey source for Walleye, during larval emergence events in early summer, and to a lesser extent throughout the rest of the summer season. These findings are important for long term management of Walleye populations and associated resources. I also assess the potential and problems of Walleye management and research from my experiences of having worked with industry, government, and university partners on this project.
Author Keywords: alternative prey, Food web interactions, invertebrate, piscivore, Predator prey interactions