Natural Movements of Smallmouth Bass and Their Response to Tournament Displacement Within the Eastern Basin of Lake Ontario

Abstract

Smallmouth Bass (Micropterus dolomieu) are one of the most popular species targeted by angling tournaments in North America, particularly in the Great Lakes region. Tournament anglers target the largest fish in these populations and can transport them across great distances (>100 km), generating concern among scientists and anglers about their ability to return to their established home ranges. Understanding the movement of sport fish by tournament anglers can aid in managing the large recreational fishery that exists in the Great Lakes region. Currently, there is insufficient research examining the natural movements or long-distance displacement of bass within large waterbodies. This study investigates tournament displacement within the Eastern Basin and the natural, non-displaced, movements of these fish. A dataset (2012 – 2016) of externally tagged Smallmouth Bass was used to examine movement, both natural and post-tournament displacement. In addition, acoustic telemetry was used to monitor the movements of an experimentally displaced and non-displaced group. From initial tagging to recapture, experimentally tagged displaced fish travelled an average of 23.4 km, while the control group travelled an average of 2.91 km. Both groups had similar lengths of time between tagging and recapture. The acoustically tagged control group were frequently detected within their initial tagging site, suggesting these fish maintain home ranges similar in size with Smallmouth Bass inhabiting smaller waterbodies. Both experimental groups displayed varying movement throughout the Eastern Basin, suggesting that many of these fish may be searching for pre-established home-ranges. No acoustically tagged fish displaced within the Eastern Basin returned to their original area of capture, suggesting they experienced difficulty navigating. These results have very important implications for fisheries managers, as well as organizers of competitive angling events for bass in the Great Lakes.