Chicago’s Looming Asian Carp Problem—What You Should Know

CARPOCALYPSE NOW: Even if you’ve never been pummeled by agitated Asian carp, these fish represent a major threat. Preventing them from entering Lake Michigan could cost taxpayers a bundle—and, depending on whom you ask, flood your basement and taint your tap water too. Here’s what you need to know.

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Asian carp leaping into the air on the Illinois River
Asian carp—which leap into the air when startled by a motor—bombard boaters on the Illinois River, where by some estimates they have replaced up to 95 percent of native fish.


Jeanne Gang Q&ASuperstar architect and MacArthur Fellow Jeanne Gang on a potential solution to the Asian carp problem »

PLUS: Hear Gang talk about her visionary plan for the Chicago River at a panel (led by Chicago editor Geoffrey Johnson) at the Peggy Notebaert Nature Museum (2430 N. Cannon Dr.; 773-755-5100) on December 7 at 7 p.m. For more information, go to

The deluge descended in the hours before dawn, nearly seven inches of rain that saturated the city—the heaviest single-day downpour since Chicago began keeping records in 1871. So biblical was that rainfall last July 23 that the Metropolitan Water Reclamation District made a drastic decision. It opened the locks downtown on the Chicago River and up north at the Wilmette Pumping Station, spewing 2.2 billion gallons of storm water and wastewater into Lake Michigan. “The action was taken to prevent overbank flooding along the waterways,” says Ed Staudacher, a supervising civil engineer with the district, calling it “a last resort.”

Though the locks were open by 3:30 a.m., some parts of the city got flooded anyway. In the Norwood Park neighborhood on the Northwest Side, for example, the streets turned into rivers, water pouring into cars parked along them. The foreign exchange student staying in Claudia Niersbach’s finished basement woke her in the middle of the night. Downstairs she found water shooting up through the floor “like a geyser.” Still, Niersbach was one of the fortunate ones: Because her house sits on a hill, it suffered only minor damage. “Our neighbors weren’t so lucky,” she says. “Water was coming in through their doors. They had to throw everything out.”

Two weeks later and 210 miles southwest, in the little town of Bath, Betty DeFord was fighting her own aquatic battle. DeFord manages Boat Tavern, which sits along the banks of the Bath Chute, a branch of the Illinois River. The bar serves as headquarters for DeFord’s annual Redneck Fishing Tournament. She began the popular two-day event in 2005, after she and her grandchildren were attacked on the river by fish that looked to her husband, Kenny, like mutated shad. “I thought they were going to sink our boat,” she recalls. “The fish were jumping out of the river like popcorn popping. We had to beat them off with an oar and a broom. We ended up with 32 in our boat. It was very, very scary.”

Those fish, of course, were the invasive Asian carp. The 1,000 or so participants in this year’s tournament netted 8,977 of them—a tiny fraction of the roughly 1 million that infest the Illinois River. “I have a personal vendetta against those stupid carp,” says DeFord. “Our community’s summertime activities are watersports. But it has gotten too dangerous to take our grandkids out there.”

What’s the connection between Claudia Niersbach’s flooded basement and Betty DeFord’s fishing tournament? The 111-year-old engineering marvel known as the Chicago Sanitary and Ship Canal (see “Sunken Treasures: Rediscovered Photographs of Turn-of-the-Century Chicago”). That 28-mile ditch, which reversed the flow of the Chicago River, connects Lake Michigan and the Chicago River to the Illinois River and thus to the Mississippi River and the Gulf of Mexico. The canal serves three main functions: carrying the city’s sewage to points south, acting as an escape hatch for heavy rains, and providing an avenue for commercial shipping. But the canal is increasingly overwhelmed by intense storms, which are likely to become more frequent as a result of global warming , according to a report prepared for the Chicago Climate Action Plan. What’s more, the canal lays out a watery welcome mat for the Asian carp, which are now at the very edge of the Great Lakes.

The battle over what to do about this looming invasion is heating up. On one side: 17 states, the province of Ontario, the Grand Traverse Band of Ottawa and Chippewa Indians, and numerous environmental organizations, including the Natural Resources Defense Council (NRDC). On the other: the City of Chicago, the Metropolitan Water Reclamation District, the State of Illinois, the U.S. Army Corps of Engineers, and businesses from as far away as New Orleans. Watching from the sidelines are outdoorsmen, homeowners, and taxpayers, all worrying about the future of the Great Lakes, the water streaming out of their taps and/or into their basements—and the astronomical size of the bill that might one day await them.

When the Chicago Sanitary and Ship Canal opened in January 1900, most Chicagoans agreed that it was a boon. Until the canal’s completion, raw sewage and effluent from the city’s tanneries, factories, and slaughterhouses got dumped into the Chicago River. From there it flowed into Lake Michigan, the source of the city’s drinking water. But the canal—considered the eighth wonder of the world in its day—sent all that nasty stuff south, where it would be somebody else’s problem. It helped eradicate the threat of cholera, typhoid fever, and other deadly waterborne diseases, allowing the city to prosper.

After further improvements in the 1920s and 1930s, the canal also yielded significant commercial benefits. It created a thoroughfare for ships to travel up from the Gulf of Mexico, through Chicago, and into the Great Lakes. With the opening of the St. Lawrence Seaway in 1959, that aquatic highway extended all the way to the Atlantic Ocean, and Chicago became (at the time) the fifth-largest port in the nation.

But if the canal was a boon, it was also a battlefield, even before it opened. None too happy about all that liquid waste headed its way, the State of Missouri mounted an immediate legal challenge. Though it ultimately lost that case in the U.S. Supreme Court, Justice Oliver Wendell Holmes Jr., writing for the majority, sounded a note that still resonates a century later. “It is a question of the first magnitude,” he wrote, “whether the destiny of the great rivers is to be the sewers of the cities along their banks or to be protected against everything which threatens their purity.”

Fast-forward to 1973. That year, Jim Malone, an Arkansas fish farmer looking for a way to control the growth of aquatic weeds, imported various carp from Asia. Malone kept the grass carp but gave two other species—silver and bighead—to the Arkansas Game and Fish Commission, which began breeding them. Bug-eyed, corpulent, and voracious, the fish gobble up just about anything green, eating from 5 to 20 percent of their body weight in a single day. (Silver carp—the prodigious jumpers that terrified Betty DeFord—can reach 40 pounds; bigheads can top 100.)

Though no one knows exactly how, some of those carp got into public waters. In 1980, a commercial fisherman caught several silver carp in a creek about 45 miles southeast of Little Rock. In the decades that followed, the fish made their way from the Arkansas River into the Mississippi and then into the Illinois, advancing at the rate of about 35 miles a year. They reproduced obscenely fast, crowding out other species. “The population in the Illinois River is higher than anywhere else in the world, including China,” says Kevin Irons, manager of the aquaculture and aquatic nuisance species program for the Illinois Department of Natural Resources. By some estimates, Asian carp have replaced up to 95 percent of the native fish population.


Photograph: Nerissa Michaels/AP



3 years ago
Posted by Great Lakes Fisherman

Your article brings to light some good points regarding the Asian Carp issue but misses the boat in a couple of areas.

The University of Illinois has been conducting regular surveys of fish populations in the Illinois River. Those surveys have shown that, even in areas heavily populated by Asian Carp, there has been no reduction of sport or rough fish populations. In short, Asian Carp have not displaced native species in Illinois' rivers.

A recent published study has shown the electric barriers in their present configuration are 100% effective in stopping live carp of all sizes. Furthermore Asian Carp are found in isolated lakes all over the Midwest indicating that natural physical barriers or the man made barriers proposed by the Natural Resources Defense Council are neither an effective or permanent solution for stopping the movement of invasive species. The truth is that the electric barriers would be just as effective as physical barriers in stopping Asian Carp and would be far less costly than severing Chicago's waterways and increasing the likelihood of flooding and polluting southern Lake Michigan.

After nearly three years of electro-fishing, poisoning, and netting only one Asian Carp of questionable origin has been found above the electric barriers. What we know now is that, while eDNA testing may work well in the laboratory, it has little relevance in predicting the existence of live Asian Carp in Chicago's waterways.

Scientists who have studied Asian Carp and the Great Lakes ecology are in agreement that, even if Asian Carp could survive in the Great Lakes and reproduce in a few of their tributaries, the worst case scenario is that their presence would be felt in only a few isolated areas. None of these scientists are predicting CarpAgeddon or that Asian Carp would destroy the Great Lakes fishery or other recreational activities and, there are no published scientific studies that would support that conclusion.

Finally, the courts rejected an injunction to close Chicago's waterways for two reasons. First, the courts determined that Asian Carp posed no immediate threat to the Great Lakes. Second, the financial harm to the City of Chicago, the State of Illinois, and the industries that rely on the waterways for raw materials and finished goods would be much greater than the known economic harm Asian Carp pose to the Great Lakes region.

The sad truth is that the public debate over Asian Carp has been more about politicians in other states and special interests groups vilifying the Army Corps and the State of Illinois in order to gain political traction to serve their own agendas while ignoring both the scientific and economic realities of the issue.

3 years ago
Posted by Kevin Troy Surratt

The Illinoian tax payer should not pay a penny, these fish destroyed the Illinois river long before they got close to the great lakes, you people had plenty warning and did nothing until it got close to the rich on the lakes.

2 years ago
Posted by Meme the cat

I eat them. My dad eats them. My mom eats them. My grandpa, the guy who made the first wooden or metal airplane in China, ate them. They're yummy.
~Me (Pronounced like the month:May)

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