Back in the 1980s, the number of fish species in the Chicago River could be counted on a single hand. Today, more than 60 species are found in the river. A new study set out to figure out what's to thank for the increase.
Every time one of the reservoirs was brought into service, the spike in the number of fish was noticeable, said Margaret Frisbie, executive director of Friends of the Chicago River. Now, that observation has been quantified.
Those will be necessary considerations, Happel said, if the region's rivers are to maintain hard-won gains in water health.Progress could be reversed if severe rainfall and flooding events become more intense and frequent, due to climate change, Happel said. The Deep Tunnel system won’t have enough capacity, and untreated waste and stormwater will once again wind up in rivers in greater amounts.
“Here, we have a long and storied history that Mayor Blandic lost his job because of a snowstorm,” said Frisbie. “Chicago has a propensity for using a ton of salt.” More isn’t better, with a single cup of salt sufficient for 500 square feet, spread evenly as opposed to clumps. “If you see salt, it’s too much,” Frisbie said.Though Happel’s analysis revealed key role the removal of wastewater pollutants had on fish diversity, algorithms and machine learning can’t predict what it will take to lure thus far reluctant species to the region’s rivers.