AUTHORS: Caleb J. Branam, Michigan State University; Holly S. Embke, Midwest Climate Adaptation Science Center, U.S. Geological Survey; Chris L. Cahill, Michigan State University
ABSTRACT: A key challenge in inland fisheries is assessing numerous lakes across vast landscapes within an agency’s jurisdiction given limited resources. To reconcile this, a variety of data-limited methods have been developed to assess the status of inland fish populations. However, these tools often do not explicitly address the potential for population dynamics, or they make strong assumptions that a given population or stock is at equilibrium. Furthermore, these assessment tools are rarely simulation tested in inland fishery settings to determine their efficacy. Without knowing how these methods perform when confronted with simulated dynamics where truth is known, the effectiveness of such tools remains uncertain. Our objective was to evaluate how commonly used assessment methods for Walleye Sander vitreus performed when tested against simulated data. To achieve this, we developed an age-structured simulation model for Walleye and then evaluated the performance of the following commonly used assessment methods: mark-recapture, catch per unit effort as an index of relative abundance, size-structure indices as an index for population status, and production-based dynamics as an index of population status. This presentation will lay out the research plan for our study, present initial results for at least one assessment method, and touch briefly on the implications of potential results.
