Population Dynamics of Burbot in the Green River of Wyoming

Burbot Lota lota are a picivorous fish species that was illegally introduced to the Green River of Wyoming in the 1990s.  Since their introduction, Burbot have proliferated throughout the Green River.  Burbot have the potential to alter the community structure of the Green River through competition and predation.  Because of the potentially deleterious effects of Burbot, managers of the Green River are interested in monitoring and eventually suppressing Burbot.  Unfortunately, no population demographics and dynamics information has been collected for Burbot in the Green River.  Baseline information on Burbot is necessary to gauge future monitoring and suppression efforts.  Our objectives were to describe age structure, growth rates, and age-specific mortality of Burbot in the Green River.  Mean back-calculated lengths at age of Burbot were estimated using a Fraser-Lee method and age structure was estimated using an age-at-length key.  Growth was described using a von Bertalanffy model and total annual mortality was estimated using a weighted catch curve.  Results from this study will provide baseline information for future management of Burbot in the Green River, as well as, foundational information for future research on Burbot in lotic systems.