Macroinvertebrates and Indicators of Water Quality
Students will examine different aquatic habitats, collect macroinvertebrates from each
and use an index to determine water quality based on the relative presence and absence of
tolerant and intolerant species of macroinvertebrates found in each sample.
1. Identify common macroinvertebrates
2. Explain the meanining of tolerant and intolerant species
3. Understand the role of an index as a tool for generating a single number for
comparison of diverse entities.
Context for Use
Resource Type: Activities:Field Activity, Lab Activity
Special Interest: Field-Based Teaching and Learning
Grade Level: High School (9-12)
Description and Teaching Materials
- Dip Net
- Latex gloves
- Squirt bottles
- Magnifying lenses
- Macroinvertebrate reference charts
1. Ask the students what they think aquatic bugs (macroinvertebrates) can tell us about the quality of water in which they live?
2. Ask the students to formulate a hypothesis about what bugs can tell us about water and write it down.
3. Go to one of locations and collect the macroinvertebrates.
4. Place the collected samples into trays keeping each substrate separate.
5. Categorize the macroinvertebrates into taxonomic groups
Biotic Index Worksheet (Acrobat (PDF) 143kB Aug25 09)
Teaching Notes and Tips
It may be difficult to identity some of the macroinvertebrates. The teacher may choose to focus on the quantity and diversity of macroinvertebrates as an indicator of water quality as compared to other sampled areas where few macroinvertebraes are found with little diversity.
Macroinvertebrates organisms require certain water conditions in order to survive. Think about how
macroinvertebrates indicate water quality. Create a designer macroinvertebrate with special adaptations. Explain
how this organism will tell us about the quality of the water just by looking at it.