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Shedd Aquarium Launches Study to Track Fish Activity in the Chicago River

New Study Dives Beneath the Surface to Explore How Restoration Affects Aquatic Life

September 21, 2023

Austin Happel, Ph.D., releases a tagged fish in a net into the Chicago River.

Shedd Aquarium’s conservation research team launched a new study this summer in collaboration with Illinois-Indiana Sea Grant and Purdue University aimed at monitoring fish activity and movements in the Chicago River made possible by the generosity of the National Resources Conservation Service. Data collected for this study will expand our understanding of how habitat restoration initiatives, such as artificial floating wetlands, influence the behavior and populations of culturally important fish in the Chicago River. Scientists will learn how often fish visit floating wetlands and if visitation is linked to reproduction, how far fish swim throughout the river, how fish respond to poor water quality events, and where fish go in the winter months. The research will focus on largemouth bass (Micropterus salmoides), common carp (Cyprinus carpio), and bluegill (Lepomis macrochirus), while including a few pumpkinseed (Lepomis gibbosus), black crappie (Pomoxis nigromaculatus), green sunfish (Lepomis cyanellus) and walleye (Sander vitreus).

Using acoustic telemetry technology, the researchers deployed 32 receivers, or listening devices, that continuously listen for unique sound signals from 80 fish that were implanted with tags that emit a unique frequency linked to each individual. As each fish goes about their lives, the sound signals are recorded by the receivers and allow the researchers to track its path, timing of movements, and areas where the fish remains or avoids. Regularly, the team will download the receivers and analyze the data to determine how fish interact within the Chicago River. The study will focus on the infamous Bubbly Creek in the South Branch to downtown’s mainstem Riverwalk, and up through the North Branch’s “Wild Mile,” while paying particular attention to the artificial floating wetlands, which were installed in both areas by Shedd Aquarium and partners at Urban Rivers.

“Many vested partners and organizations throughout Chicago have been working to advocate for, restore and protect our river system, and now we will obtain insights directly from the fish on how they interact with restoration initiatives,” said Austin Happel, research biologist at Shedd Aquarium. “As we track fish throughout the waterway, we gain knowledge about their behavior and needs, which can help guide us as stewards of the river and in turn make their lives better.”

Over the last several years, Shedd Aquarium’s Happel has worked with others to better understand how fish communities in the Chicago River respond to environmental policies and habitat enhancements, but his field work has focused primarily on whether the addition of floating wetlands provides valuable spawning habitat by surveying for tiny, clear larval fish. “While surveys of larval fish help us understand when and where species are spawning in the waterways, this represents only one way that fish interact with the environment and in an approximately 3-month season,” said Happel. Now, the expansion of the project on adult fish behaviors will help inform conservation management.

“Allowing the fish to show us the habitats that they prefer or avoid allows for better informed restoration activities – not only in Chicago, but in other urban waterways too,” said Happel.

Today, more than 60 species of fish are known to live in the Chicago River, which points to an increasingly healthier ecosystem for people and wildlife. Chicago’s waterways serve as critical economic, recreational and cultural assets to the city and subsequently create environments conducive to aquatic life. Continued learning can continue to inform further conservation efforts to restore and protect these vital freshwater ecosystems.

“We are excited to partner with Shedd Aquarium and Austin Happel on this interesting study to evaluate fish habitat usage in the Chicago River,” said Tomas Höök, Director of Illinois-Indiana Sea Grant and Professor in Purdue University’s Department of Forestry and Natural Resources. “In addition to the habitat management implications of this study, we are enthusiastic about the outreach potential and training opportunity provided,” added Höök, who together with Happel is collaborating with Paris Collingsworth from Illinois-Indiana Sea Grant and Luke McGill, a Purdue graduate student.

Shedd acknowledges and extends gratitude to its partners for this research including Illinois-Indiana Sea Grant and Purdue University. Additional appreciation to Illinois Department of Natural Resources, Chicago Department of Transportation, Wendella Tours and Cruises. A special thanks is extended to the Metropolitan Water Reclamation District of Greater Chicago for their assistance in locating fish for this study. In addition to the Natural Resources Conservation Service, the aquarium’s urban freshwater research efforts are made possible with support from the McGraw Foundation and the National Fish and Wildlife Foundation. The study is an integral piece to enhancing the understanding of aquatic life in urban settings as well as discovering management actions that improve these aquatic environments.

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Credit: ©Shedd Aquarium