**ABSTRACT NOT FOR CITATION WITHOUT AUTHOR PERMISSION.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 nschloesser@usgs.gov. Questions? Contact the GLFC via email at frp@glfc.org or via telephone at 734-662-3209.**

Sea lamprey quantitative environmental DNA surveillance

¹Nicholas Schloesser, ¹Chris Merkes, ²Chris Rees, ¹Jon Amberg, ³Mike Steeves, ⁴Margaret Docker, and ⁵Weiming Li

¹U.S. Geological Survey, Upper Midwest Environmental Sciences Center 2630 Fanta Reed Road, La Crosse, WI 54603, USA

²U.S. Fish and Wildlife Service Northeast Fishery Center P.O. Box 75, 227 Washington Ave. Lamar, PA 16848, USA

³DFO Canada Sea Lamprey Control Center, Sault Ste. Mari, ON, Canada

⁴University of Manitoba, Department of Biological Sciences, 50 Sifton Road, Winnipeg, MB, R3T 2N2, Canada

⁵Department of Fisheries and Wildlife, Michigan State University, East Lansing, MI, USA

September 2017

ABSTRACT:

Invasive Sea Lamprey (Petromyzon marinus) are currently managed by the Great Lakes Fishery Commission to reduce pest populations below levels that cause ecological and economic damage. One technique to improve stream population assessments could be molecular surveillance in the form of environmental DNA (eDNA) monitoring. We used quantitative polymerase chain reaction (qPCR) to correlate eDNA concentration with Sea Lamprey densities initially in laboratory tanks and then in streams. We found a positive correlation between adult Sea Lamprey densities and eDNA concentrations in tanks. However there was not a correlation between spring eDNA concentrations and adult Sea Lamprey trap catch numbers. For larval laboratory tank density trials and fall field samples, eDNA concentrations were consistently below our limit of quantification. Therefore, we examined detection probability rather than concentration with laboratory tank densities and estimated larval densities in the field. We found higher detection probabilities with greater larval lamprey tank densities, but we had insufficient statistical power to observe significance. We observed similar results for the fall field samples, although they may have been confounded by errors with the electroshocking assessments. The ability to assess Sea Lamprey densities from a water sample could be a powerful tool to improve traditional assessment and stream ranking techniques. Further research related to Sea Lamprey eDNA might lead to a better understanding of sampling strategies and could help eDNA surveillance of Sea Lamprey become a more reliable technique to use going forward. Our results support the continued use of detection probabilities rather than copy numbers for low eDNA concentrations and that even at low concentrations, eDNA analysis can detect the presence of animals that traditional assessment methods might miss. Additionally, the rapid sample collection and analysis of water samples from many streams might help focus traditional assessment efforts, thereby improving the efficiency of the Sea Lamprey control program.