Macroinvertebrates

The organisms that we found from all three sites of the North Channel are listed in the table below:

Type	Number Found
Leech	14
Scud	3
Sow Bug	1
Snail	2
Planarian	2
Cray Fish	1
Aqua Worm	1

These macroinvertebrates are indicators of the water quality of the North Channel of the Chicago River because they differ in their sensitivity to water pollution. Most of these organisms are sensitive to pollution, habitat changes and natural changes. As a result, these organisms are used to determine the “health” and “cleanness” of a water source. Scientists use these organisms to evaluate water quality because they each have a certain range of chemical and physical conditions in which they can survive. Some of these organisms can survive in polluted water while others can ‘t survive in polluted water. A bad water quality index is one in which more pollution tolerant macroinvertebrates are found instead of more sensitive ones. Pollutant tolerant organisms include leeches, aquatic worms, Pouch snails etc. Examples of sensitive intolerant to pollution organisms are mayflies, stoneflies, Riffle beetles, and other types of snails etc. Pollution intermediate organisms include clams, Cray fish, Dragonfly nymphs, Beetle larvae etc. Thus a fairly good water source having a good water quality index is one that has a mixture of pollution sensitive organisms.
We used physical means to capture these organisms. Nets were used to capture these organisms. We were able to actually go into the water because we wore body waders.

Significance of The Results

Leeches and Aqua worms are pollution tolerant organisms. Scuds, Sow bugs and Cray fish are pollution intermediate organisms. Snails and planarian are pollution sensitive organisms. These results show us that there is a variety of pollution tolerant organisms as well as pollution sensitive ones, therefore, the water quality based on this is fair.