The U.S. Fish and Wildlife Service will be surveying the sea lamprey population of the Chippewa River in Isabella County in August.
Last year the river was treated for the invasive species.
The service is tracking how well the treatment worked, and seeing if additional treatments are needed.
Scott Grunder is with the U.S. Fish and Wildlife Service.
He said to count the lamprey, they drop a chemical into the river that makes lampreys come out of their burrows.
“In this particular instance we will be using it in a granular form so we just drop it from the back of a boat through special arms and it settles in the bottom and it's kinda like a time release capsule, it hits the bottom and then after a little bit it releases a capsule and the larvae come out of the substrate,” Grunder said.
He said the chemical is not harmful to other wildlife in the river.
“It’s very difficult to remove sea lamprey from a given body of water because they come back. We treat them, kill upwards of 95 percent of them and then in any given year in the spring the adults co me back and spawn.”
Grunder said treatment on the Chippewa is needed every three years to keep the lamprey population under control.