Zebra mussels are an aquatic invasive species that filter feeds, therefore reducing phytoplankton biomass, which negatively affects zooplankton biomass. Reductions in zooplankton biomass in particular may be detrimental to young-of-year walleye growth and recruitment.

In order to properly assess the impacts of zebra mussels on walleye recruitment, graduate student Holly Kundel, will be using historical walleye catch data collected by the Minnesota Department of Natural Resources. Walleye recruitment success will be compared among lakes with and without zebra mussels, and within lakes pre- and post-invasion. The two measures of walleye recruitment that we will use are 1) walleye survival until their first fall and 2) recruitment to the fishery. 1) Walleye Survival Until their First Fall: will be indexed by catch rates in fall electrofishing surveys. 2) Recruitment to the fishery will be indexed by year class strength based on gill net catch rates. Lake characteristics including lake size, depth, water clarity, productivity, and temperature will also be used to account for other variables that are known to influence walleye recruitment success. In order to test our hypothesis that zebra mussels negatively influence walleye recruitment success, we will utilize Bayesian hierarchical models.

Stay tuned for project updates and results!