**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**

Using an eel ladder-trap to trap sea lampreys: proof of concept

D.G. McDonald² and D. Desrochers³

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

³ Milieu, Inc. 1435 Chemin de Saint-Jean, La Prarie, QC, J5R 2L8

March 2012

Abstract

This study evaluated the utility of an eel ladder for trapping invasive sea lamprey in the Laurentian Great Lakes. It was based on the premise that sea lampreys share the anguilliform swimming style and slender body morphology with eels; characteristics functionally related to successful ascension of eels on eel-ladders. In the first part of the study, sea lampreys were subjected to a prototype, ladder-like trap fitted with a staggered peg ‘eelladder’ substrate and set at an incline. Ninety-one percent of the lampreys successfully ascended the eel-ladder and were trapped when exposed to a high flow rate down the ladder. Retention of captured lampreys was 100%. No significant modifications were needed, thereby demonstrating the prototype was a viable trap option selective for sea lamprey. In a second part of the study, the slope, peg spacing, and flow down the eel-ladder substrate were manipulated to both determine potential configurations of the prototype that would maximize the trap performance and identify the structural and hydrodynamic requirements favouring the ascension of sea lamprey. Ninety-six percent of sea lamprey were able to ascend inclines with and without flow, up to an angle of 80°, when provided with a complex structural environment. The highest success at ascending was achieved with the smallest peg spacing at an incline of 45° under the highest flow rate. This research provides the basis for the development of ladder traps selective for sea lamprey, as well as insights into the capacity of sea lamprey to surmount inclines in the wild.