Home Range and Movement Patterns of Burbot in Koocanusa Reservoir, Montana, USA
James L. Dunnigan and Cameron L. Sinclair
Abstract.—Adult burbot Lota lota from Koocanusa Reservoir, Montana, USA were surgically implanted with acoustic (n = 28) and combined radio/acoustic tags (n = 12) to quantify movements and home range. Fish were tagged from November 2003 to April 2004, and tracking efforts were conducted approximately weekly during daylight hours on Koocanusa Reservoir using a motor boat during the period of mid-December 2003 to July 2005, which spanned two burbot spawning seasons. Six (15%) tagged burbot were never relocated after release, and an additional seven (17.5%) of the tagged burbot either died or shed their tag within 60 d after release. We relocated 34 marked burbot (85%) on at least three occasions (mean = 10.0). Burbot frequently used the deepest portions of the reservoir, especially during the summer months. We estimated that the mean 50%, 75%, and 90% kernel home ranges were 14.6, 22.6 and 32.3 km2, respectively. We found no evidence that burbot home range differed within the 2 years of this study. Although we did observe burbot moving a maximum distance of up to 64.3 km, we were unable to discern any general movement patterns by month or capture location. Individual burbot tagged in this study had relatively high fidelity to the original capture side of the reservoir, and almost half of our marked burbot were never relocated on the opposite side of the remnant Kootenai River thalweg, and those that did cross the thalweg do so infrequently. One burbot was entrained through Libby Dam approximately 134–276 d after capture and tagging.