GRAND RAPIDS, Mich. (AP) — Federal researchers have completed a study of sea lamprey in a western Michigan waterway ahead of plans to build a barrier aimed at controlling the invasive species.
U.S. Fish and Wildlife Service researchers set traps and used sex pheromones to conduct a study into how many sea lamprey use the Grand River as spawning grounds, The Grand Rapids Press reported .
Researchers also studied whether lamprey were able to get through a dam that’s set to be removed.
The study began in April and wrapped up earlier this month. The findings will be presented in late June.
The lamprey were either killed or used for research after they were caught and tallied for a population estimate, said Peter Hrodey, a supervisor fish biologist with the U.S. Fish and Wildlife Service.
There’s currently no evidence that lamprey have breached the dam, but it’s only a matter of time, said U.S. Geological Survey research ecologist Nicholas Johnson.
Sea lamprey invaded the Great Lakes in the last century and decimated native fish until a poison was developed that brought them under control.
Grand Rapids Whitewater plans to build a $10 million structure to serve as a barrier to the eel-like parasites that attack fish such as trout, salmon and whitefish. The adjustable hydraulic structure would be upstream of the dam that currently serves as a natural barrier into Michigan’s largest watershed. The project is scheduled to be complete by 2025.
Grand Rapids Whitewater projects that expanding the recreational use of the river and riverfront will have an economic impact between nearly $16 million and $19 million annually.