Dr. David Bergerhouse, Southern Illinois University, spawning a walleye just outside the Quad Cities Nuclear Station.

November 1, 2023

The Quad Cities Clean Energy Center Fish Hatchery’s Impact on Illinois Waters

Photos courtesy of the author.

When you think about a nuclear power station, your first thought is likely not of a fish hatchery. Illinois, however, has the only nuclear generation site in the country with an active fish hatchery that is operated privately. Since 1984, Constellation Energy (formerly Exelon) has operated a hatchery program at the Quad Cities Clean Energy Center, just north of Cordova. The hatchery is located on the Mississippi River, near the middle of Pool 14.

Unlike the LaSalle State Fish Hatchery, which is located at Constellation Energy’s LaSalle Clean Energy Center and operated by the Illinois Department of Natural Resources’ (IDNR) Division of Fisheries, the Quad Cities hatchery is privately operated by long-term employees of Southern Illinois University and Constellation Energy.

When the concept for turning the Station’s old cooling canal into a fish rearing pond was initiated, experts from Southern Illinois University were selected to design and operate the “experimental” project. Significant input from IDNR, Iowa Department of Natural Resources and multiple federal agencies were melded together as a best professional judgement program to maintain and enhance the Mississippi River fishery. Nearly 40 years later, the hatchery is still in operation and growing more than just fish.

An individual holds up a small long fish from a fishing net with more small fish.
A portion of the walleyes produced will receive a liquid nitrogen freeze brand on their side to signify that they are hatchery fish.

Production and Release of Walleye

The primary focus of the hatchery has traditionally been walleye production. The hatchery has a goal of stocking 175,000 2-inch fingerlings into the Mississippi River each year. Extra fish produced are then stocked in public waters at the discretion of the DNRs. These production goals were established by both Illinois and Iowa DNRs and have changed over the years. Stocking began in 1986 with the brood stock (adults) all being local fish. Those fish are captured, taken to the hatchery to be spawned and then released back to the river.

Traditionally, once the eggs hatched and the fry were three to five days old, they were released into the cooling canal to grow to 2 inches. That worked relatively well for 30-plus years, but eventually a significant upgrade was needed to maintain production.

Constellation Energy invested resources into a new RAS (recirculating aquaculture system), to replace the 48-acre canal with three 1,500-gallon circular tanks. In the first year this intensive culture system produced 235,000 2-inch walleye in roughly 40 days. Fifty-three percent of the 3-day-old fry put into the system survived to 2 inches in length and were later stocked into the Mississippi River near the Quad Cities. Forty years of stocking—nearly 10,000,000 fingerlings—and highly effective regulations have turned the Mississippi River from Dubuque to the Quad Cities into one of the best walleye fisheries in the country.

The hatchery also supports six other Constellation sites across Illinois, with three sites having cooling lakes open to the public. LaSalle, Braidwood and Clinton lakes all have long term lease agreements with IDNR to manage the fisheries for the public. These lakes are the primary cooling source for the nuclear reactors but are also excellent resources for the public to enjoy fishing, especially in the greater Chicagoland area where those opportunities are sparse. Constellation and IDNR staff meet annually to discuss the state of each lake and look at improvements. Typically, those improvements are additional fish stockings, which is done by both IDNR and Constellation.

Rearing Alligator Gar

An individual with a gloved hand holds up a long small fish from a fishing net with more small fish.
Alligator gar are stocked when they are large enough to avoid predators, with the hope that they will naturally reproduce once again in Illinois waters.

In 2009, the IDNR introduced a plan to reintroduce alligator gar, led by fisheries biologists Rob Hilsabeck and Trent Thomas. In 2011, Constellation hatchery staff began working with these biologists to grow out some fry IDNR had received from the U.S. Fish and Wildlife Service (USFWS). The hatchery had some available capacity and thoroughly enjoyed working with the species. That first-year trial has since blossomed into a reoccurring partnership to help restore alligator gars across the state. In addition to the fish grow out, Constellation conducts significant amounts of public outreach concerning the environment, so educating the public about this species has become a standard topic during these programs. Being able to answer the “Why on earth would we want those in the water?” question can be answered in a meaningful manner. In addition, visitors to the Quad Cities Hatchery can view the species up close and then develop an appreciation for the critical role it has in the environment.

Growing Endangered and Threatened Freshwater Mussels

While the hatchery primarily grows fish, in 2010 it began working with freshwater mussels under the direction of the USFWS, Iowa DNR and IDNR. Freshwater mussels have a significant role in maintaining the quality of the water in the Mississippi River and have been significantly impacted by commercial harvest in the late 1800s, water pollution until the 1970s, and, most recently, infestation by zebra mussels, an invasive species introduced into the Great Lakes in 1986 in ballast water in ships from Europe.

A close up of several brownish, green native mussels all lined up in neat rows and columns on top of a terrycloth towel.
Federally endangered Higgins eye mussels are marked with a black epoxy dot prior to be stocked in the river.

Through the permits that allow the cooling water to be returned to the river, the fish hatchery began growing freshwater mussels, specifically endangered and threatened species, to aid the agencies in their work to restore these “living rocks” that clean our water. To date, the hatchery has produced tens of thousands of endangered mussels and has stocked them in inland Illinois waters as well as other Quad Cities area streams.

The Quad Cities Hatchery has been operating for nearly 40 years in partnership with IDNR. These partnerships are critical to the operation of successful management programs for the state, and ultimately are an excellent way to produce better public engagement and educational opportunities for the current—and future—environmental advocates of our waterways.

Jeremiah Haas has been a fisheries biologist at Constellation in northwest Illinois for the past 24 years. He worked for the IDNR Fisheries and Natural Heritage Divisions in the past, giving him a wide range of experiences in multiple programs. In his free time, he will retreat to the woods or the water, spends a lot of time coaching youth sports, and writes about the outdoors for several entities across the Midwest. You can reach him at jeremiah.haas@constellation.com or (309) 227-2867 if you have questions.

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Submit a question for the author

Question: Hello,

I am a project manager that works for the Tennessee Valley Authority (TVA) at the Sequoyah nuclear station near Chattanooga, Tennessee. The Sequoyah nuclear station takes cooling water from the Tennessee River and we are interested in the possibility of installing a fish hatchery similar to what Quad Cites uses to limit fish kill. Is there a contact you could refer me to at Quad Cities that could provide some background information on the QC hatchery? Any help much appreciated!