Sea Lamprey Control Program Continues to
Improve Control Approaches
BY JESSICA BARBER, MARQUETTE BIOLOGICAL STATION
where alarm cue and larval sea lamprey odor responses are being tested on the
Upper Ocqueoc River (Lake Huron). Credit: Erica Adams, Michigan State University
Innovation: a new idea, device, or method. When used in a management setting, innovation is a process that brings together various novel ideas in a way that will improve upon the current way of ‘doing business’. The primary method used in controlling sea lamprey populations in the Great Lakes is the application of TFM, a chlorinated nitro-phenol pesticide which is selectively toxic to larval lampreys and otherwise benign when applied at the appropriate dosage. However, the Sea Lamprey Control Program recognizes the need to remain innovative in its approaches to controlling sea lampreys to stay ahead of the game and diversify the toolbox. Several innovative research projects are underway this field season that are poised to make the Program more effective at controlling sea lampreys in the future.
Understanding how pheromones and alarm cues influence sea lamprey migration behavior is critical to increasing the efficiency of traps and barriers. Pheromones could be used to pull sea lampreys to locations that can either be trapped or treated with lampricide more effectively. Alarm cues could be used to push sea lampreys away from locations that can’t be trapped or treated with lampricide effectively. These two novel approaches could be used in concert to manipulate migration behaviors in a way that enhances the effectiveness of the Program.
and Bruce Eldridge monitoring eel ladder
style traps at the Cheboygan River (Lake
Huron) trap site. Credit: Savannah Bell,
Biological Science Technician, USFWS
Improving trapping technology is another area of the Program where efforts are being focused. Sea lamprey traps can be very effective at capturing sea lampreys under certain conditions. However, where one catches sea lampreys one is almost certain to capture non-target species. Eel ladders have the potential to increase trap retention of sea lampreys and decrease the time it takes to sort non-target species and release them in good condition. Eel ladders are upstream fish passage devices that use wetted ramps outfitted with vertical pegs designed to take advantage of the anguilliform swimming motion of sea lampreys. Sea lampreys will ascend the wetted ramp dropping into a retention basin, leaving non-targets to swim freely at the base of the eel ladder.
River (Lake Superior) study site where a low-voltage DC fish
guidance system (NEMO) is being used to lead sea lampreys into
traps.Credit: Jason Pynnonen, Biological Science Technician, USFWS
Another method to improve trap efficiency is to use pulsed direct current as a non-physical lead to guide sea lamprey into traps. At present, trapping is only effective at physical barriers to sea lamprey migration, where individuals will repeatedly encounter traps as they search for a way to migrate upstream. Laboratory studies using a portable, low-voltage DC fish guidance system (NEMO) were successful at directing sea lampreys into traps. The NEMO leads are designed to be portable, easily deployed, and capable of handling high flow events and debris load. Deployment of the NEMO into a medium sized river will allow the Program to evaluate its use in increasing trap efficiency in the absence of a physical barrier.
As you can see, the U.S. Fish and Wildlife Service is collaborating with researchers throughout the Great Lakes basin to develop innovative technologies that will assist in the fight against sea lampreys. A pest management program can only truly be effective if it is multi-faceted and eager to seek innovative solutions to an ever changing environment.