Simulated Changes in Lake Trout Yield, Trophies, and Forage Consumption under Various Slot Limits

Abstract

Abstract In Flaming Gorge Reservoir, Utah–Wyoming, mean size of lake trout Salvelinus namaycush harvested by anglers has decreased. We hypothesized that this decline resulted from either overexploitation of lake trout by anglers or from a decline in lake trout growth owing to decreases in forage fish availability. While investigations to examine these hypotheses were being developed, we wanted to examine the potential for increasing the size of lake trout harvested without dramatically increasing the consumption demand of the lake trout population on forage fishes. To accomplish this goal we used population models to examine survival patterns of lake trout under different slot limits. Results of the population model were used in bioenergetics simulations to examine the consumption demand of the lake trout population. Total yield, the number of trophy fish harvested, and the biomass of prey fish consumed by lake trout were examined for each of seven harvest scenarios. Simulations indicated that the more re...