**The title, authors, and abstract for this completion report are provided below.  For a copy of the completion report, please contact the GLFC via e-mail or via telephone at 734-662-3209**

A decision analysis assessing the trade-off between sea lamprey control and rehabilitation of native fishes at de facto sea lamprey barriers

R. L. McLaughlin², E. R. B. Smyth², T. C. Pratt³, M. A. Koops⁴, L. A. Vélez-Espino⁵, and P. Sullivan⁶

² Department of Integrative Biology, University of Guelph, Guelph, ON, Canada N1G 2W1

³ Great Lakes Laboratory for Fisheries and Aquatic Sciences, Fisheries and Oceans Canada, Sault Ste. Marie, ON P6A 2E5 Canada

⁴ Great Lakes Laboratory for Fisheries and Aquatic Sciences, Fisheries and Oceans Canada, Burlington, ON L7R 4A6 Canada

⁵ Pacific Biological Station, Fisheries and Oceans Canada, Nanaimo, BC V9T 6N7 Canada

⁶ Sea Lamprey Control Centre, Fisheries and Oceans Canada, Sault Ste. Marie, ON P6A 2E5 Canada

July 2012

Abstract

Decision tools are needed to assess trade-offs between actions to control invasive species by restricting their movement and actions to reduce habitat fragmentation for native species. We conducted a quantitative evaluation of management options for the dam located near the mouth of the Black Sturgeon River, Lake Superior. The dam restricts invasive sea lamprey (Petromyzon marinus) to the lower 16 km of river, but is considered an impediment to rehabilitation of migratory walleye (Sander vitreus) and provincially-listed lake sturgeon (Acipenser fulvescens). Relocating the dam farther upstream and treating more of the river with lampricides could lead to recovery of walleye and lake sturgeon, while controlling sea lamprey, but less favourable outcomes are equally possible and federally-listed northern brook lamprey (Ichthyomyzon fossor) would be exposed to lampricides. Selective fish passage could also facilitate walleye and lake sturgeon recovery, while controlling sea lamprey and protecting northern brook lamprey, providing that passage rates are effective and stakeholders accept slower rates of recovery and higher economic costs. Field studies quantifying reproductive success of walleye and lake sturgeon placed above the barrier and sea lamprey breeding below the barrier could reduce uncertainty in the potential for recovery of native species and production of sea lamprey.