The U.S. Army Corps of Engineers approved a plan last year to spend as much as $832 million on an infrastructure project on the Illinois River, about 40 miles from Lake Michigan. The engineers want to replicate a similar $270 million project that already exists 10 miles downstream, and which continues to cost about $16 million every year to maintain. 

The point of these massive infrastructure projects? – Keeping two Asian carp species out of Lake Michigan.

The Problem 

“It’s more than just some fish though,” said Chuck Shea, according to a PBS NewsHour report. Shea is a USACE project manager working at the Chicago Canal’s Fish Dispersal Barrier Facility, the currently existing $270 million project. “There’s an entire ecosystem in the Great Lakes that’s of concern (and) that has great economic as well as environmental benefits.”

First introduced in the U.S. in the 1970s, the Asian carp were used in Arkansas to control algae, weed and parasite growth in aquatic farms, weeds in canal systems, and as one form of sewage treatment. Within a decade, the Mississippi River flooded many of these farms and the imported carp escaped and began dominating the Mississippi River Basin. In fact, according to the National Wildlife Federation, Jerry Rassmussen, a U.S. Fish and Wildlife Service biologist, warned his superiors about the escapes and the threat nearly 20 years ago, but his warnings were ignored because the political climate did not favor the introduction of any restrictions. Asian carp were still escaping from flooded Missouri fish farms as late as 1994. 

Map of the Distribution of Asian Carp in America

The two species of Asian carp in North America have made their way north through the Mississippi River Basin and threaten to breach barriers to the Great Lakes. COURTESY OF USGS, DNR.

Since their introduction, the carp has infested the Mississippi River and its tributaries, including the Illinois River, damaging native ecosystems by consuming nutrient sources at rates native species are not able to compete with. Everywhere they have turned up, Asian carp have stifled native species – including bass, crappie, bluegill, buffalo fish and catfish – and taken over rivers. And when they grow to a certain size, they have no effective predators to limit their population. Now, they threaten to make their way through Chicago’s system of canals into Lake Michigan and spread throughout the Great Lakes.

But it’s not just the environmental impact that has motivated the federal government and state of Illinois to invest hundreds of millions of dollars to stop the spread of these invasive species. The Associated Press reported that the Great Lakes support an enormous $7 billion fishing industry that could disappear should the Asian carp enter Lake Michigan. Not only will the carp eliminate species traditionally fished commercially, they will make it nearly impossible to fish recreationally.

The silver carp – one of the two species of Asian carp in North America – is famed for its ability to “jump” out of the water and strike human victims. At 40 pounds, the carp can “seriously injure” boaters and damage boats travelling at 20 mph, according to the United States Geological Survey. Water skiing on the Missouri River in particular is now exceedingly dangerous because most of the fish jump behind the boat.

The Solution

Existing infrastructure on the Chicago canals and Illinois river has not been enough to keep the Asian carp from entering the Great Lakes. Independent reports by the Chicago Tribune, the Detroit Free Press and The New York Times have found conclusive evidence of Asian carp activity well past existing barriers and in the Great Lakes.

Asian carp have managed to slip past powerful jolts of electric current produced by three tonnes of underwater electric steel bars. These fences, built 25 miles upstream from Lake Michigan on the Chicago Canal, form the largest such barrier in the world and cost the taxpayer $16 million a year in maintenance. But they’re clearly not enough. 

If the $800 million plan proposed by the USACE receives the funding it needs from Congress, it would include an air bubble curtain, an acoustic fish deterrent – which would emit underwater ultrasonic sound waves – and flushing locks, as well as electric fences. This “Brandon Road Barrier” is estimated to be completed in 2027. 

Brandon Road Asian Carp Barrier Facilities

The new Brandon Road Barrier, set to cost about $800 million dollars, will be fitted with state-of-the-art mechanisms to keep Asian carp away, including an electric barrier to shock the fish and an acoustic deterrent that will emit underwater ultrasonic sounds to keep carp away. COURTESY OF US ARMY CORPS OF ENGINEERS.


Until then, besides funding the Chicago Canal barrier, the federal government subsidizes a program that pays fishermen to catch as many Asian carp as they can. This program, launched by the Environmental Protection Agency in 2010, costs about $1 million a year, but has been successful in removing 7.8 million pounds of carp. In fact, the program has decreased Asian carp’s leading edge population by 93%.

Yet, if the example of the Asian carp in the United States has proven anything, it is that exploiting invasive species can be an expensive and dangerous business. We tried – and failed – to forcefully engineer nature to meet our immediate needs. Our comeuppance? The hundreds of millions of dollars we’re paying to fix that mistake.

Do you live in a region affected by Asian carp or some other invasive species? Leave a comment below telling us how you’ve benefited or been disadvantaged by them!