**ABSTRACT NOT FOR CITATION WITHOUT AUTHOR PERMISSION.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 Richard.ready@montana.edu or via phone at (406)994-7365. Questions? Contact the GLFC via email at frp@glfc.org or via telephone at 734-662-3209.**

Biological and social impacts of invasive species in the Great Lakes: Development of scenarios through expert judgement and assessment of recreational angling impacts

Ready, R.C.¹, T.B. Lauber², G.L. Poe³, L.G. Rudstam², R.C. Stedman², and N.A. Connolly²

¹Department of Economics and Agricultural Economics, Montana State University, Bozeman, MT 59715

²Department of Natural Resources, Cornell University, Ithaca, NY 14850

³Dyson School of Applied Economics and Management, Cornell University, Ithaca, NY 14850

May 2016

ABSTRACT:

Predicting the impacts of invasive species is daunting, particularly in large systems threatened by multiple invasive species, such as North America’s Laurentian Great Lakes. We developed a scenario-building process that relied on an expert panel to assess possible future impacts of aquatic invasive species on recreational fishing in the Great Lakes. A range of plausible, science-based, internally consistent scenarios were developed for five different aquatic invasive species threatening the Great Lakes, Asian carp. Grass carp, hydrilla, Northern snakehead, and quagga mussels. An economic model of recreational behavior was used to project the impacts of the scenario on fishing participation and value. We conclude that aquatic invasive species can either improve or harm recreational fisheries in the Great Lakes, but potential negative scenarios are more likely and have larger impacts than potential positive scenarios. Worst case scenarios result in losses in recreational fishing value in the Great Lakes region of up to $129 to $139 million, and decreases in fishing effort of up to 375,000 to 400,000 days annually.