PAW PAW, Mich. — Since the 1950s, the U.S. Fish and Wildlife Service (UFWS) has been taking steps to control the invasive sea lamprey population and their threat to the Great Lakes–including here in Southwest Michigan.

Beginning Tuesday, the agency will be kicking off their ten-day control efforts, treating sections of the Paw Paw River in Berrien and Van Buren Counties.

“Sea lamprey control is essential,” Lo Freitas, UFWS lampricide treatment supervisor, said. “They do quite a number on the fishery. So, they’re very voracious predators.”

In response to the threat, Freitas says the agency regularly treats streams with a chemical known as lampricide, which is designed to kill sea lamprey in their larval stage before they have a change to swim downstream.

In total, UFWS will be working along 77 miles of the Paw Paw River and targeting more than 70,000 lamprey larvae.

Sea lampreys—native to the Atlantic Ocean and invasive to the Great Lakes—are a highly-destructive species that can decimate populations of fish, significantly harming both the ecosystem and economy of the region, according to UFWS.

They use their suction cup mouth filled with sharp teeth to feed on a number of Great Lakes fish, including: trout, walleye, and salmon.

While lampreys only feed about 12-18 months, Freitas says each one is capable of eating up to 40 pounds of fish during that time, posing huge risks to commercial and recreational fishing.

“We’re talking about an animal that is very, very well adapted to the Great Lakes, has no natural predators, no real economic use,” Freitas said. “And something that can do great damage to the fish in the Great Lakes.”

During this time, Freitas warns people may notice the water turning a bright-yellow, greenish color, but says the chemical does not pose a risk to human health or the environment.

People would have to be exposed to 15,000 times the typical lampricide treatment concentration for any harm to occur, according to Freitas.

“That means you can swim, you can tube,” Freitas said. “We do really apply them at precise concentrations to remove the lamprey while minimizing impacts to other species we make sure that we are doing our due diligence before, during and after.”

The agency is also asking that anyone with an agricultural irrigation system turn it off while treatment is underway.

For more information, go here.