Prior to the 1930's, Sea Lampreys were not native to Lake Michigan. Since then, Sea Lampreys have caused major damage to fish within the Great Lakes. In the 1940's and '50's, Sea Lampreys decimated lake trout, whitefish, and chub populations in the Great Lakes.
Sea Lampreys aren't parasites their whole life. However, the short period of time they spend as parasites can cause serious problems.
"The sea lamprey in its parasitic phase when it reaches the lake, it parasitizes on large fish. So lake trout, salmon, burbot, other fish species," said Shawn Nowicki, Fish Biologist with the U.S. Fish and Wildlife Service.
In a collaborative effort between many groups across the Great Lakes States and even Canada, the U.S. Fish and Wildlife Service attempts to stop the sea lampreys increase their numbers.
"Our objective here is to target the larval phase and kill them before they transform into the parasite and move out and cause all of the damage," said Nowicki.
The U.S. Fish and Wildlife service operate sea lamprey control programs out of two spots in Michigan; one right here in Marquette and another downstate in Ludington.
Traveling across the Great Lakes, the group spreads lampricide into streams and rivers to knock out the masses of sea lampreys. The lampricide that is used does not harm plants or wildlife, nor does it affect humans or farm animals with the concentration that is used.
"It's formulated in such a way that fish are not affected by it, they can actually metabolize it. Whereas lamprey are not able to metabolize it, that's why they eventually die from the chemical exposure," said Tiffany Opalka-Myers, Biological Science Technician with the U.S. Fish and Wildlife Service.
Thanks to these treatments, the number of sea lamprey are going down in Lake Michigan.