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Washington State University

Water Bugs – Engager: Skill Level Two

Water Bugs

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ENGAGER – Skill Level: Two

"Caddisfly Larvae" - University Bug Scope, University of Illinois
Caddisfly Larvae

Activity: What’s swimming in your stream? – The Sequel

Objective: Compare stream sites and discover the elements that support biotic integrity.
Science Skills: Observation, Comparing and Measuring, Hypothesizing, Using Tools
Life Skill: Communicating, Critical Thinking, Record keeping

Preparation Activities:
Making a Kick Net – Stream Assessment Guide
Check “It’s All Connected” for a list of publicly accessible streams known to currently support freshwater insects and other macro invertebrates. Also look under “It’s All Connected” to find a map of impaired water bodies in your county. Specifically look for impaired water bodies in publically accessible areas.

What You Will Need:
Nets, kick net, white bottomed dish pans, magnifying glasses, rulers, pads, pencils, sample jars(?), squeezable sports bottle, turkey-baster, plastic gloves, water wading boots, trash bags, copy of the Stream Assessment Guide.


1. Use the list of local impaired streams or zoom in on the Costal Atlas interactive GIS map to find an impaired fresh water location you can visit. (If using the Coastal Atlas, you may have to make sure the stream you are interested in is publically accessible.)

2. Make plans to visit an impaired stream. Make sure it is publicly accessible and safe. (see Safety Guidelines)

3. First write your location and date on your stream observation log sheet, then describe the characteristics of the water. Is it clear or cloudy, cold or not so cold, moving fast or barely moving at all? If you have a photographer, photograph your location.

4. Follow the collecting and sampling instructions in the Stream Assessment Guide.

5. Use the “Key to Macroinvertebrate Life in the River” in the Stream Assessment Guide, or other guides to identify as many bugs as you can.

6. Visit a steam from the second list. Repeat the activity on a separate observation log sheet.

7. Look at the Macroinvertebrate Pollution Tolerance Index in the Stream Assessment Guide and compare your samples.

Asking the Right Questions:
Were there some bugs you found in both places? If you found the same bugs in both places, did that same bug look or behave differently? Were there some bugs you found in one location and not another? What might attribute to these bugs being in one place and not another or acting differently? How could you test your assumptions? What do you think having more bugs or a wider variety of bugs might indicate?