Free talk: Sustaining a Wild Cutthroat Trout Fishery

Join the Draper Natural History Museum for our April Lunchtime Expedition, when Jason Burckhardt, Fisheries Biologist with Cody Region of the Wyoming Game & Fish Department, presents "Suppression of an Illegally Introduced Walleye Population to Sustain a Wild Trout Fishery in Buffalo Bill Reservoir."
 

Buffalo Bill Reservoir harbors a relatively unique adfluvial population of rainbow and cutthroat trout that annually migrate into the North Fork Shoshone and tributaries to spawn. This adult trout migration fuels a fishery of national importance. Juvenile trout migrate from the North Fork of the Shoshone and tributaries to Buffalo Bill Reservoir to grow and mature.
 

Walleye, discovered in Buffalo Bill Reservoir in 2008, were illegally introduced as early as 2002. Per capita walleye consumption of juvenile trout was substantial and the potential expansion of the walleye population threatened the sustainability of the trout population. The possibility of suppressing this walleye population was researched, methods of suppression were analyzed, and an age-structured population model was developed that suggested the suppression of this walleye population was feasible using gillnetting of spawning congregations and unlimited angler harvest.
 

Suppression of this walleye population in the form of gillnetting and electrofishing removals during spring spawning congregations and unlimited harvest by anglers has occurred since 2017. Otoliths removed from Walleye captured during suppression activities have been used to populate the age-structured population model and suggest that suppression efforts have been successful at preventing the growth of the Walleye population in most years.