An Assessment of Burbot Life History in Minnesota with a Focus on Movement Dynamics and Spawning Vulnerability

Author

Tyler Robinson

Date of Award

4-2022

Document Type

Thesis

Department

Biology

First Advisor

Andrew Hafs

Abstract

Burbot have a circumpolar range spanning from rivers of Alaska to lentic systems in Minnesota. Although Burbot population dynamics have been studied, their movement dynamics have been rarely investigated. Our objectives were to assess seasonal home range changes of Burbot in a closed-lentic system and quantify the scale of spawning aggregations. Sixty-six Burbot were implanted with acoustic transmitters in Bad Medicine Lake, Minnesota, with 32 surviving the length of the study period between 10 April 2019 to 11 June 2020. The peak spawning date for Burbot in Bad Medicine Lake was estimated to be mid-March, when home range estimates were two times larger than at any other point in the study. Female estimated home range size was significantly larger than males across the study. Fish movement was synchronized with ice formation in December and continued through March when they explored new areas. Home range estimates were smallest in mid- April, likely due to post-spawn behaviors. Spawning locations were estimated using the ArcGIS Optimized Hot Spot Analysis tool. Results show there are multiple locations in Bad Medicine Lake that Burbot used during the spawn. However, Burbot heavily used the eastern shore, which includes steep, rocky drop-offs compared to the west side. Our results provide evidence to suggest Burbot do cluster during spawning, potentially increasing their vulnerability to anglers. High exploitation rates are likely to occur in situations where spawning Burbot, which are actively feeding, are met by intense angling pressure. Our results will assist fisheries managers in determining appropriate measures to protect the fish during a potential vulnerable stage. Results highlight how movement patterns differ in the species throughout its circumpolar distribution. Future research should continuously monitor Burbot populations and assess how populations can be affected by changes in their environment, specifically climate change.

Recommended Citation

Robinson, Tyler, "An Assessment of Burbot Life History in Minnesota with a Focus on Movement Dynamics and Spawning Vulnerability" (2022). Biology Graduate Theses. 4.
https://pines.bemidjistate.edu/thesis-biol/4