14The sea lamprey Petromyzon marinus is an invasive pest in the Laurentian Great Lakes basin, 15 threatening the persistence of important commercial and recreational fisheries. There is 16 substantial interest in developing effective trapping practices via the application of behavior-17 modifying semiochemicals (odors). Here we report on the effectiveness of utilizing repellent and 18 attractant odors in a push-pull configuration, commonly employed to tackle invertebrate pests, to 19 improve trapping efficacy at permanent barriers to sea lamprey migration. When a half-stream 20 channel was activated by a naturally derived repellent odor (a putative alarm cue), we found that 21 sea lamprey located a trap entrance significantly faster than when no odor was present as a result 22 of their redistribution within the stream. The presence of a partial sex pheromone, acting as an 23 attractant within the trap, was not found to further decrease the time to when sea lamprey located 24 a trap entrance, relative to when the alarm cue alone was applied. Neither the application of 25 alarm cue singly, or alarm cue and partial sex pheromone in combination, was found to improve 26 the numbers of sea lamprey captured in the trap vs. when no odor was present -likely because 27 nominal capture rate during control trials was unusually high during the study period.
28Behavioural guidance using these odors has the potential to both improve control of invasive 29 non-native sea lamprey in the Great Lakes as well as improving the efficiency of fish passage 30 devices used in the restoration of threatened lamprey species elsewhere. 31