Chemicals like PCBs and organochlorine pesticides are known as “bioaccumulates” because they don’t break down easily, and animals in contaminated areas become more contaminated the further they are up the food chain. By the time fish are big enough to be desired by humans for food, they’ve accumulated enough toxins to be dangerous, Stahl explained.
Like PCBs, organochlorine pesticides have also been banned for years in the U.S. The compound DDT is probably the most notorious of the organochlorine pesticides.
State biologists try to assess each of the state’s watersheds on a 5-year cycle, and this year, they’ll test fish throughout the Upper Wabash River basin. They focus mainly on known hot spots; the Kokomo Reservoir, Stahl said, is always a “non-issue.”
Even before the massive federal cleanup at Continental Steel, the Wildcat was showing signs of improvement, as nature, aided by spring floods, worked its magic.
The Wildcat was once a Level 5 stream all the way to the Wabash River, but based on data from the last 10 years, the stretch of the Wildcat in Tippecanoe County now has fish which are considered safe to eat.
“Species are now starting to recruit back into the system that haven’t been seen in 100 years,” Stahl said. “These remediations work, but how fast they work is the question.”
The April 19 flood was a show of force from the Wildcat, but the pollution still in the stream, along with the tons of trash the Wildcat Guardians and others haul out of the stream every year, indicate that the stream has taken as much punishment as it has dished out.