Quantifying seasonal variations in space use within the home range of Burbot

ObjectiveAdvances in acoustic telemetry have assisted biologists in understanding migration patterns, space use, survival, and the effects of human influences on aquatic species. Using fine-scale positioning, fisheries managers can quantify home range size fluctuations throughout the year and even identify spawning areas. Burbot Lota lota population dynamics have been studied across their range, while movement dynamics have been briefly investigated. Our objective was to assess seasonal variations of Burbot space use using estimations of home range size with an attempt to infer spawn timing.MethodsThirty-two acoustic-tagged Burbot were used to study home range size in Bad Medicine Lake, Minnesota, from April 2019 to June 2020.ResultFemale estimated home range size was significantly larger than that of males. Estimated home range size increased following ice formation in December and continued through March. Average home range estimates were largest in the middle of March and smallest in April, assumed to be caused by spawning and postspawn behaviors, respectively.ConclusionThe results suggest that Burbot movement increased during the winter months, which may cause potential increases in vulnerability during spawning. High exploitation rates are possible in situations where spawning and feeding Burbot encounter elevated angling pressure. Future research should continue to assess the movement dynamics and potential site fidelity of Burbot populations by monitoring spawning grounds and if the same areas are used year after year. The results of this study improve the knowledge of areas used by Burbot in lakes, which can assist with management of Burbot in Bad Medicine Lake. Furthermore, we highlighted how Burbot movement increased during spawn timing, which could contribute to increased encounters with anglers. This study provides the first explanation of the year-round spatial analysis of Burbot in a closed lake system. We found that Burbot space use increased during winter following ice-on and peaked in mid-March, which is assumed to be associated with reproduction. Overall, female space use was larger than that of males across the study period.Impact statement