Seasonal effects on the acceleration of largemouth bass and Northern Pike in Toronto harbour

BackgroundHabitats are heterogeneously distributed across landscapes, and animals move through them to access different resources, resulting in energetic consequences. In the Laurentian Great Lakes, nearshore areas provide important habitat for the majority of fish species; however, differences in the distribution and composition of physical (e.g., vegetation, depth, fetch, and substrate type/size and temperature) habitat attributes create habitat heterogeneity. We used high-resolution acoustic telemetry data combined with acceleration sensors to test how spatial and temporal factors relate to acceleration of two ecologically and economically important fish species, Largemouth Bass (Micropterus nigricans) and Northern Pike (Esox lucius), within a system of coastal embayments in Toronto Harbour, Lake Ontario.ResultsFor both species, we found that sites characterized by higher vegetation cover, shallower depths, and decreased fetch (i.e., coastal vegetated and wetland sites) were associated with lower acceleration values. We also identified several areas within Toronto Harbour that likely serve as important movement corridors between higher suitability sites. Temporal variation of acceleration was significant for both species and was influenced by season and diel period. Both Largemouth Bass and Northern Pike exhibited increased acceleration during spring and summer. Both species exhibited peak acceleration at dawn and dusk.ConclusionThe use of accelerometers was instrumental in identifying important habitats, movement corridors, and elucidating temporal trends across seasons and diel periods. Our results highlight the importance of incorporating habitat connectivity between habitat patches used for different purposes into conservation and restoration planning.