**ABSTRACT NOT FOR CITATION WITHOUT AUTHOR PERMISSION. The title, authors, and abstract for this completion report are provided below. For a copy of the full completion report, please contact the author via e-mail at hdawson@umich.edu. Questions? Contact the GLFC via email at slrp@glfc.org or via telephone at 734-662-3018.**

Incorporation of expert judgment in an operating model of the control program to evaluate trade-offs for sea lamprey management

Heather A. Dawson², Michael L. Jones³, Alexander C. Maguffee³, Scott Miehls⁴, Nicholas S. Johnson⁴, Gale Bravener⁵

²University of Michigan, Flint, 264 Murchie Science Bldg. 303 E.

Kearsley St., Flint, MI 48502 USA; Phone: 810-762-3360

³Quantitative Fisheries Center, Department of Fisheries and Wildlife,

Michigan State University, 480 Wilson Road, Room 13, East Lansing,

Michigan 48824 USA; Phone: 517-355-4478

⁴U.S. Geological Survey, Great Lakes Science Center, Hammond Bay

Biological Station, 11188 Ray Road, Millersburg, MI USA 49759. Phone:

989-734-4768

⁵Department of Fisheries and Oceans, 1219 Queen Street East, Sault Ste

Marie, ON P6A 2E5 Canada. Phone: 705-941-3003

July 2020

ABSTRACT:

We used a Sea Lamprey Management Strategy Evaluation simulation (SLaMSE) model to explore the potential for using trapping strategies as a complement to lampricide control while incorporating expert judgment into the stream selection process. Previous work suggested that if trapping strategies reduce the frequency with which large, expensive streams are treated, the benefits can be substantial. Expert judgment (EJ1) streams are large, expensive streams, and we hypothesized that incorporating expert judgment in the model by treating these streams on a fixed schedule would decrease the effectiveness of a hybrid strategy significantly. However, we found that trapping strategies that targeted streams that (1) were difficult to treat with lampricides, (2) had regular sea lamprey production, or (3) had low densities of spawners were most effective at reducing the lakewide number of spawners relative to targeting other stream types whether or not expert judgment was incorporated. These trapping strategies require low costs ($5,500 per stream) and moderate capture rates (30%) to be a cost-effective complement when used with lampricides relative to using only lampricide control. While the effectiveness of trapping was greater without theincorporation of expert judgement, differences were small, and the effectiveness of trapping depended much more on the type of streams that were trapped.