Diet of burbot and implications for sampling

Burbot (Lota lota) are an apex piscivore that were illegally introduced to the Green River drainage, Wyoming, raising concerns for the conservation and management of fishes throughout the basin.  However, relatively little is known about the diet of non-native burbot.  The objectives of this research were to characterize diet composition of burbot and identify differences in diet composition as a function of sampling gear.  Diet composition was characterized using frequency of occurrence, percent by number, and percent by weight to identify the importance of each prey type to burbot.  Diet composition was compared across gears to identify the relationship between gear and diet.  Fishes were present in the stomach contents of nearly all burbot sampled and composed 62–100 percent of the stomach contents of burbot greater than 300 mm.  Prey diversity was greatest in diets of burbot sampled with small-mesh hoop nets.  Results from the current study provide important information on the diet of non-native burbot and highlight the potential influence of gear on diet studies.