Spatio-Temporal Patterns of Adult Northern Pike in An Urban Embayment

Widespread development has led to impairment of freshwater coastal embayments, which provide critical and unique habitat for many fish species. In Toronto, Ontario, restoration efforts have been directed towards improving the amount and quality of fish habitat in Toronto Harbour. Assessing annual habitat use and movement for a top predator and key game fish, such as northern pike (Esox lucius), is essential for the implementation of appropriate restoration strategies. From 2010 to 2012, forty northern pike were tagged with acoustic transmitters with built in pressure (used to infer depth) and temperature sensors. Since their release, an acoustic telemetry array containing 48 receiver stations installed throughout Toronto Harbour has tracked the movement of these pike among different areas in the coastal embayment, and between the inner and outer harbours. Here we present results from an ongoing embayment-wide study of annual habitat use by northern pike with a focus on pre- and post-spawning and overwintering habitat. Results from this study will help inform management decisions and provide insight into the long-term movements of a top-predator in a large freshwater coastal embayment.