Does Movement of Yellow Perch Across Management Boundaries in Lake Erie Matter for Setting Quotas?

The management of harvested fish populations is often complicated by the movement of fish between management units (MUs). As our ability to assess fish movement increases, it creates opportunities to evaluate the suitability of current management boundaries. Lake Erie yellow perch (Perca flavescens) are managed as four MUs. Stock assessments are done for each MU assuming no movement. However, an ongoing tagging study suggests that yellow perch move across MU boundaries, raising the concern that not taking this movement into account in the stock assessment might bias estimates of allowable catch. We used historical data to compare population estimates from stock assessment models that assume movement between the MUs to a model that does not. By specifying a range of plausible levels of movement, informed by the current tagging study, we were able to determine how sensitive the stock assessments are to alternative levels of movement. Our results will help determine the importance of MU structure and of movement assumptions on the management of yellow perch in Lake Erie, and consequently help to assess the value of further movement research for this species.