This map shows the spread of invasive bighead and silver carp in US waterways, with red lines showing where all life stages have been found, yellow where adults are common, and blue where only individual adults have been found. (Courtesy of the US Fish and Wildlife Service)
Five Great Lakes senators said that the Trump Administration has risked irreversible harm through delays in the construction of a barrier to keep invasive carp out of Lake Michigan.
In a letter to the US Army Corps of Engineers, Sens. Tammy Duckworth and Dick Durbin of Illinois, Gary Peters and Elissa Slotkin of Michigan, and Tammy Baldwin of Wisconsin said that two unexplained pauses in work on the Brandon Road Interbasin Project near Joliet, Illinois, have placed the completion of the project in jeopardy as well as increased its cost. The most recent pause ended Sept. 2, but “the lack of explanation for it raises concerns about this Administration’s commitment to the project and the possibility of future delays,” the senators wrote.
Last month, the Illinois Department of Natural Resources reported that sampling crews removed hundreds of young invasive silver carp from an Illinois River site 80 miles from Lake Michigan. The senators said that the discovery highlights the urgency of the Brandon Road project.
The senators noted that Congress authorized the construction of the Brandon Road barrier in 2020 and has since approved $300 million in funding for the project. Partners in Illinois and Michigan have also invested more than $100 million into the project. The US Army Corps of Engineers estimates that the project will ultimately cost $1.15 billion.
It is meant to keep invasive carp, including silver carp, from spreading from the Mississippi River basin to the Great Lakes through the Illinois River. The barrier will consist of a series of layered deterrents at a choke point in the river.
Those layers include an electric field to repel or stun fish swimming upstream, a continuous air bubble curtain, underwater speakers that will emit deterrent sounds, a flushing lock that helps to keep nuisance species downstream, and an air bubble-based washing system to clear nuisance species from barge hulls. The project also includes channel improvements, new boat ramps, and support facilities to maintain the deterrents.
Silver, Black, Bighead, and Grass carp are voracious feeders that originate from Southeast Asia and arrived in the lower Mississippi River about 50 years ago, according to the US Fish and Wildlife Service. Grass Carp have been found in all of the Great Lakes except for Lake Superior, whereas the other three species remain in the Mississippi River basin.
The invasive carp have spread through the Mississippi River’s major tributaries, degrading river and lake ecosystems by wiping out local populations of zooplankton, plants, mussels, and fish, the USFWS said. Federal officials are working with local partners on about 80 projects to manage the invaders.
All four species were imported in previous decades and raised in fish farms, with some stocked in ponds, aquaculture sites, and wastewater treatment facilities to control unwanted plants and insects. The fish escaped into open waters and quickly spread throughout the country.
Last year, Trump signed an executive order that directed his administration to work quickly in support of the Brandon Road project. It also called for Illinois to acquire the land needed for the project and issue state-level permits needed for construction.
“These invasive carp are nearing the entry point to the Great Lakes, which, if breached, would irreparably damage native fish species like walleye, yellow perch, and lake whitefish,” Trump said in the executive order. “This poses a significant risk to Great Lakes fishing, boating, recreation, and tourism, which support tens of thousands of jobs and billions of dollars of commerce annually.”
The senators said in their letter that the invasive carp are closing in on an invasion of the Great Lakes, and they noted that as few as 10 breeding pairs reaching Lake Michigan could lead to irreversible harm. They urged the administration to keep in touch about any changes to the Brandon Road project.
