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
Guide to Identification of
Fresh Water Microorganisms - Microscopic autotrophic organisms
Protozoa - heterotrophic only
Other fresh water
plankton (Animalia, Monera, etc)
Arthropods - segmented,
Microsoft Word version (361kb)
Pdf Version (2121kb)