Why would a compliance guy at Aqua America care about bugs in the Illinois’ Kankakee River when most people try to avoid or kill bugs?
Kevin M. Culver of Aqua America
First off, I am not an entomologist (aka a bug expert) so why do I care about bugs? This is the first question I ask when conducting a source water presentation or manning our source water display booth at events.
Most of the responses I receive depending on the age of the participant, are that:
· Bugs are bad and need to be eliminated
· Bugs are part of the food chain necessary to sustain life in the river
Both responses are somewhat correct but not exactly why I care. We do not want bugs in our drinking water but they are an important part of the food chain.
I care about the bugs because one can determine the health of a stream by the number and type of bugs living in the stream. Not only can the bugs be used to determine water quality but fish and fresh water mussels can also be used as biological indicators of water quality.
Bugs And Your Water
So what are (macros)? These include aquatic insect such as larvae, worms, leeches and snails that can be found under rocks, attached to plants and in the bottom sediments of rivers and streams.
Not all macros that are found indicate species of water quality. In fact, only 36 different groups of macros make up the specimens used to determine water quality.
The 36 Groups: What You Need to Know
As a citizen scientist through the River Watch program, I have been trained on techniques on how to properly collect and identify the water quality indicator of macro-invertebrates.
I collect bugs at four assigned sites annually within the Kankakee watershed, located in the northeastern part of Illinois. The same sites are used each year to determine water quality at that instant and to trend this result against previous sampling events.
Each of the 36 indicator species is assigned a tolerance value (TV) to pollution between “0” being completely intolerant to pollution and “11” being highly tolerant to pollution.
The weighted average tolerance value of all the bugs collected at a site is the water quality indicator, officially known as the Macro-invertebrate Biological Index (MBI).
If a bug is intolerant to pollution, it means it hasn't acclimated to pollution, which mean the river is clean. If a bug is tolerant to pollution, it means the bug has indeed been exposed to pollution - so much so that its body has changed its reaction to pollution.
So when Aqua tells everyone that the Kankakee River is one of the “cleanest” rivers in the Midwest, it's the bugs that prove it. The water quality in Rock Creek in the Kankakee State Park is one of the few sites n Illinois that are statistically getting cleaner, according to the bug results.
This year I also collected 849 bugs from my Kankakee River site that had the lowest ever average tolerance value (MBI) at 4.29.
Why Should You Care About the Bugs?
Along with just being cool, they are an integral part of our source water protection plan. You can determine water quality by which bugs are present or absent and they are a great way to educate and demonstrate to young and old about the importance of source water protection.