Macro-invertebrates
Benthic macro-invertebrates are invertebrates (or animals without a backbone) that live on the bottom of streams during all or part of their life cycle. Their name sounds complicated, but it literally describes these creatures. "Benthic" means bottom dwelling, and "macro" indicates that benthic macro-invertebrates can be seen with the naked eye. Although benthic macro-invertebrates (BMI´s) often go unnoticed because of their size and habitat, they are an extremely important part of river ecosystems, and serve as a link in the food web between decomposing leaves and algae, and fish and other vertebrates. (http://www.naparcd.org/benthicmacro.htm)
Water Quality
Excellent 1.0-2.0
Good 2.1-2.5
Fair 2.6-3.5
Poor greater than 3.6
THE HEALTHIEST RIVER BASED ON THE RESULTS IS: CHICAGO RIVER