Lamprey Invasion

Out of control parasites invade Lake Champlain

Story by Rian Hunt

Photo provided by U.S. Fish and Wildlife Services

Imagine fishing in Lake Champlain. Your pole begins to tug, and you start reeling your line in. You catch a fish and attached is an eel-like creature that is bigger than your fish. Al Sweenor, of Lake Champlain Trout Unlimited didn't have to imagine-this scenario happened to him.

“I caught a salmon that was 19-inches long and attached was a lamprey 23-inches long. The salmon was smaller than the lamprey,” Sweenor said. “The lamprey was consuming it.”

According to Sweenor, Lampreys are fish with gills and a suction cup shaped mouth with rasp teeth. They consume the body fluids of a host because they do not have their own digestive system; they suck the fluids from fish by latching on the side of fish, or under the belly. This results in damaging or killing the fish. One lamprey can kill up to 40 pounds of fish during its life span, which ranges from 12 to 18 months.

"There are a lot of them and they are doing a lot of damage."

Lampreys are out of control pest that have been attacking and feeding on fish in Lake Champlain. They feed on fish such as lake trout, Atlantic salmon, pike and many more. They have decreased the fish population tremendously and need to be put under control.

Lampreys have increased in population within the past seven years and continue feeding on their primary source, salmon. In less than a month, salmon will be migrating back up to the North Country waters. They are considered indicator species and are very important for recreational benefits as they contribute to the major waterways in the North Country.

Lampreys invaded the Lake Champlain region around the 1800s. It is believed they reached the great lakes sometime in the 1930s after the canals were open for migration. They were never expected to become so out of control that the number of fish would decline.

There are many lamprey control methods, but the budget is limited to what can be spent on this outbreak. The project for lamprey control started in 1982 with the training of a Division of Fish and Wildlife (DFW) team to do treatments with methods called TFM and Bayer 73.

TFM is the primary method. TFM stands for 3- trifluoromethyl, and 4- nitro phenol. It kills sea lamprey larvae in streams with little or no impact on other fish and wildlife. This method is not harmful to humans. In some areas TFM is not effective. So, the control method used if TFM is not effective is Bayer 73, a lampricide that stops the lampreys from breeding, which helps stabilize the lamprey population. Other methods are lamprey traps and barriers that block upstream migration of spawning lamprey.

According to Don Lee, a member of Lake Champlain Trout Unlimited, the acceptable rate for lampreys in one area is in the 20's, and for Lake Champlain, the lamprey rate is in the high 80's and lower 90's. “There are a lot of them and they are doing a lot of damage,” Lee said.

If the population of these juice-sucking nuisances is not controlled, the fish population will continue to decrease, and the waters will lose their wildlife. Not only will the waters suffer, but the fishermen will lose their game, and the community may lose its sports fisheries. A long-term experimental study should be the next method to see what will truly rids the lampreys from the waters.

Have you ever seen a lamprey?

Lamprey Control

Many efforts are in use to try to control the lamprey problem in the North Country water region. These efforts are conducted in Lake Seneca, Cayuga, and Champlain. The clean-up project started in 1982 and continues approximately every four years.

•  Sea lamprey assessment: Primary method that kills sea lamprey larvae in streams with little or no impact on the fish and wildlife. This technique is not harmful to humans or other mammals.

•  Lampricide Control: In some areas the chemical TFM is used to control the lamprey and in other areas Bayer 73 is used.

•  Lamprey barriers: Block upstream migration of spawning lamprey.

•  The sterile male release technique: This method reduces spawning by making the male lamprey sterile so they are unable to reproduce.