Fighting sea lamprey in the Crystal River

By Joe Blondia
Sun contributor

The Crystal River is a little green today but this is not an early St. Patrick’s Day celebration by our Chicago friends. The U.S. Fish and Wildlife Service is treating the river to control the lamprey population. Lampreys are a type of fish that belong to the order Agnatha, which are the jawless fish. Originally from the Atlantic Ocean, they found their way into the Great Lakes after the construction of the Welland Canal around Niagara Falls. Having no natural predators, the lamprey became a devastating parasite to the lake trout population in the lakes and then the salmon. The lamprey breed in the river and their young live in the shallow slow areas around the bank.

Last month, researchers using backpack shockers looked in the shallow areas of the Crystal and discovered enough larval lamprey to warrant treatment with a lampricide chemical. While the chemical is stressful to the salmon, it targets the lamprey specifically. Due to the large number of spawning salmon, the Fish and Wildlife service postponed the treatment until the majority of salmon had already spawned. In order to track the progress of the lampricide, a vegetable based dye is used that turns the water a chartreuse color. As the lampricide moves downstream and becomes diluted, so does the dye, and soon the lampreys will be the only ones who knew it was there. Visit www.fws.gov for more information on this important conservation work.

Joe Blondia teaches Environmental Science at The Leelanau School in Glen Arbor.

This GlenArbor.com story was sponsored by the Foothills, a year-round motel and cafe on the east side of Big Glen Lake with eight clean and comfortable rooms.