Combating a Great Lakes invader with new technologies: The fight against invasive sea lamprey
From land to waterways, we at the U.S. Fish and Wildlife Service work alongside partners to combat self-sustaining populations of invasive species, such as sea lamprey. Our invasive species efforts are a critical component in native species conservation and our research is essential in our conservation outcomes.
Biologists remove adult sea lamprey from a trap on the Manistique River in Michigan. Photo by Lynn Kanieski/USFWS.
The Great Lakes formed more than 10,000 years ago as glaciers receded at the end of the last ice age. These vast inland seas form the largest surface freshwater system on Earth and support 139 native fish species including lake trout, a prized game and food fish. This freshwater fish is a top predator in the Great Lakes and was commercially harvested on massive scales until the fishery collapsed in the 1950s from a combination of overfishing, pollution, loss of spawning habitat and parasitism by invasive sea lamprey.
Invasive sea lampreys are a jawless, parasitic fish native to the Atlantic Ocean that entered the Great Lakes system via manmade locks and shipping canals. Their aggressive behavior and appetite for the bodily fluids of fish wreaked havoc on native fish populations and decimated an already vulnerable lake trout fishery.
Sea lamprey control is a critical component of fisheries management in the Great Lakes, benefiting important fish stocks by significantly reducing the number of fish killed by sea lamprey. The U.S. Fish and Wildlife Service and Fisheries and Oceans Canada implement sea lamprey control in the Great Lakes, while the Great Lakes Fishery Commission coordinates and funds the control program.
Sea lamprey control technologies
The diversity of sea lamprey control technologies has grown since the start of the program in 1953. The evolution of our research helps us to better understand this invasive species and protect aquatic resources. We are advancing technologies across the Great Lakes region that will benefit the future of aquatic conservation.
In the 1950s, we worked to identify a pesticide, known as a lampricide, effective at controlling sea lamprey larvae without significantly impacting other species. Scientists tested nearly 6,000 chemical compounds before identifying a lampricide known as TFM. Biologists apply TFM to lamprey-infested streams in the Great Lakes to reduce larval sea lamprey populations. We have used TFM successfully for more than 60 years to suppress sea lamprey populations in the Great Lakes.
Traps and nets are standard tools in capturing sea lamprey to assess adult sea lamprey abundance. We operate traps and nets in about 40 tributaries in the Great Lakes in partnership with tribal nations during the spring and early summer. Additionally, there are more than 30 barriers on Great Lakes streams in the United States that block migrating sea lampreys from reaching spawning locations. We work with partners to maintain and implement barriers in streams when other control options are not feasible, too expensive or ineffective.
Working closely with the U.S. Army Corps of Engineers, we are researching novel barrier designs. Corps engineers incorporated sea lamprey swim performance data when redesigning a dated Harpersfield Dam along the Grand River in Geneva, Ohio. The new stepped design concept used for the dam has been proposed for several new feasibility studies. The design includes permanent attractant-water sea lamprey traps with low-flow channel entrances and a lampricide delivery system for more effective application of lampricides downstream of the barrier.
Collaborating with partners on research
Our collaboration with partners is a valuable part of our work. Alongside our partners, we are researching improvements to selective fish passage, identifying supplemental control techniques and supporting research on the next generation of lampricides.
As part of FishPass, a selective fish passage project led by the Great Lakes Fishery Commission in partnership with federal, tribal, state and local governments and natural resource agencies, our biologists consult on project planning including site selection and trap designs. FishPass replaces the deteriorating Union Street Dam in Traverse City, Michigan, on the Boardman River with a new barrier. Below the new barrier, scientists will test technologies and techniques that can sort and pass desirable fishes without allowing harmful invaders like sea lampreys through. Once the project is completed, we will provide larval and adult assessments upstream and downstream of the facility and will be among the first to field test any new technologies developed as part of the project.
Supplemental control techniques such as attractants and repellents could guide sea lamprey towards traps or away from suitable spawning habitats. Supplemental controls are being researched and tested to enhance control where physical, biological or social challenges limit the effectiveness of lampricides or barriers.
Partnering with the U.S. Geological Survey and Department of Fisheries and Oceans Canada, we are testing and evaluating supplemental control tools in a multi-decade adaptive management project. The study will be conducted on a dozen streams in northern Michigan and Ontario, Canada, for a dozen years and is designed to increase confidence in our understanding of where and when removal of an adult sea lamprey results in fewer future larvae.
We support the investigative work of the U.S. Geological Survey’s Upper Midwest Environmental Sciences Center in developing the next generation of lampricides. Our biologists will test possible alternative lampricides to TFM in the field after researchers at the center have completed laboratory tests. This field research will help verify successful alternative lampricides for possible future use.
Using the best available science we are driving technological innovation in sea lamprey control. We are far from alone in our efforts, working closely with partners to enhance existing control techniques and develop new control methods effective at stopping invasive sea lamprey. Approaching sea lamprey control from multiple angles has reduced sea lamprey populations in the Great Lakes basin, creating favorable conditions for the recovery of native fishes like lake trout. Continued sea lamprey control will help preserve a healthy Great Lakes ecosystem.