Prioritizing in-stream barrier removal in Great Lakes tributaries

A key challenge in lake sturgeon restoration is their limited access to historical riverinespawning grounds, which are often upstream of barriers (dams, road?stream crossings). The removal ormodification of instream barriers can restore migratory pathways for sturgeon and other importantspecies, but the costs (economic, species invasions) and benefits (access to breeding habitats) differamong potential projects. The restoration community lacks a transparent method for comparing thesecosts and benefits to assess which barrier removal projects would offer the greatest return on investment.To address this problem, we are undertaking a three?step project with the goal of providing a decisionsupport tool for prioritizing barriers for removal. First, we have developed the most comprehensivedatabase to date of the location of dams (n=7,091) and road?stream crossings (n=268,818) in the GreatLakes Basin. Second, we have created a predictive statistical model to estimate the passability of each ofthese potential barriers for fishes. Third, we are currently developing mathematical optimization modelsto determine optimal barrier removal sequences to enhance the amount of breeding habitat madeavailable for a given budget. We will discuss the key factors that drive barrier prioritization, future dataneeds, and the strengths and limitations of applying optimization approaches to enhance lake sturgeonrestoration efforts.