Bioassessment Techniques

Recommended Grade:  Secondary
The diversity, abundance, and condition of fish, insects, algae, plants, and other organisms are used to determine the health of specific bodies of water.  Studying these factors is called biological assessment. 

Bioassessment is an effective but qualitative way at looking at the health of water.  Aquatic plants and animals constantly exposed to the effects of changing environmental conditions including biological, physical, geologic, and chemical conditions.  It is a valuable tool to monitor and how to interpret what is found to decide how to control the health of the waterways.

Students need to learn to identify the organisms first.  Included in this lesson is a guide to identification of fresh water microorganisms.  It is intended to be a quick way to try and get students motivated to identify the organisms.  You can collect samples using a net or a jar.  Make sure you include plant material, since most of the organisms would be feeding on decaying material.
Depending on the type of microscopes you have will depend on the detail of these lessons.   

On the page that says “Mission Creek Stream Study,” have the students record what they see.


Mission Creek Stream Study   (pdf version)
Guide to Identification of Fresh Water Microorganisms - Microscopic autotrophic organisms (i.e. Algae)
Protozoa - heterotrophic only
Other fresh water plankton (Animalia, Monera, etc)
Arthropods - segmented, exoskeletons

Microsoft Word version (361kb)
Pdf Version (2121kb)

Mission Creek Home Page