A quantitative risk assessment model for the management of invasive yellow perch in Shuswap Lake, British Columbia

I developed a quantitative risk assessment model in a Bayesian decision analysis framework to evaluate management options for the potential invasion of non-native yellow perch (Perca flavescens) in Shuswap Lake, British Columbia. Probability distributions of key model parameters were determined by eliciting expert opinion during a workshop and by a mail-out survey. The model produced distributions of weighted average probabilities of abundance and spatial distribution of yellow perch in the lake 10 years after introduction. I found that impacts of a yellow perch invasion on sockeye salmon would be best mitigated by undertaking a combination of actions including education, enforcement, rotenone, and physical removal. The rank order of management options was not sensitive to assumed carrying capacity or rate of spread. Based on my results, I recommend that sampling efforts continue in Adams and Shuswap Lakes to monitor whether yellow perch spread and quantify how they interact with sockeye salmon.