When introduced, predatory fish can have dramatic influences on ecosystems to which they are not native. In our lakes at ELA, pike introductions to predator-naive lakes resulted in a total extirpation of all other fish species.  Similarly, research has shown that the presence of particular prey species can greatly influence the growth and energetics of predatory fishes (like the freshwater shrimp, Mysis).

Two graduate students in our lab have explored or are exploring questions regarding predator-prey interactions. Brendan Allan conducted behavioural trials in the Biology Aquatic Facility at Lakehead University and performed further mesocosm trials at the IISD-Experimental Lakes Area to evaluate the response of prey to native predators. Specifically, he compared the risk-taking behaviour of yellow perch from lakes with and without predators to the presence of pike when a food attractant was present.

Eric Randall will be assembling a database on Walleye in Rainy Lake, Ontario to determine how environmental changes in the form of prey species (as well as in management and regulation changes) have shaped patterns in their abundance through time.