The Chicago River dyeing event drew crowds along the Riverwalk and boaters who rode as the city waterway was turned bright green by The Chicago Plumbers Union Chicago Journeymen Plumbers Local 130 for St Patrick's Day celebrations. Spectators aboard boats from the Freedom Boat Club and people watching from E. Wacker Drive and the Loop took photos and waved as floats and bands moved through the parade route.
Photographs from the celebration show people in leprechaun outfits riding boats and a wienermobile alongside marching bands and pipe players in the Loop. Local business figures and elected officials appeared among parade participants and onlookers. The event was carried out using the same dyeing practice that has been part of the city's St Patrick's Day tradition since the first green water incident in the 1960s.
Scientists Monitor Fish Behavior And Environmental Concerns
Researchers from Shedd Aquarium Purdue University and the Illinois Indiana Sea Grant have tracked more than 80 fish in the Chicago River system since June 2023 using acoustic tags that ping about every minute. Receivers were placed in the Wild Mile on the North Branch Bubbly Creek on the South Branch and along the Riverwalk downtown to record fish movements and responses to events such as habitat restoration flooding and sewage overflows.
Austin Happel a research biologist at the Shedd said the team saw a handful of tagged fish in the downtown main branch during a prior river dyeing. He said the fish did not rush to find shelter and that the researchers "didn't see changes in what they were doing that day or even the next couple of days afterwards so it doesn't seem to be causing them to be agitated." The tracked species include largemouth bass common carp bluegill pumpkinseed black crappies walleyes and green sunfish among others.
The researchers contrasted the modest response to river dyeing with a heavy rain driven sewage overflow in early July 2023 that sent fish moving long distances as if seeking refuge. Happel said such overflows can deplete oxygen and in some cases lead to fish kills. The Illinois Environmental Protection Agency has said the vegetable dye the city uses has no toxic effect although the dye's exact ingredients are not public. Environmental groups including the Sierra Club Illinois Chapter Friends of the Chicago River and Openlands have questioned the practice and noted related incidents such as social media driven dumping of Mountain Dew and unsanctioned colorant releases into the North Branch.
