A CIESE Collaborative Project

Water Quality

Using Macroinvertebrates as a Clue to Water Quality


This is an open-ended lesson in which students will use the information they have collected from their pond sample to make a statement about the quality of the water in the pond.


Students will:

  • Assess the environmental quality of a pond water sample based on the presence of certain organisms
  • Understand that all living things are affected by the environment

Teacher Information

Use the following information to design a class activity that explores the relationship between the quality of water and the macroinvertebrates that are found therein. The goal is to bring students to the understanding that one way to tell if the water is polluted or not is by finding out what organisms live in it.

Background In ponds the presence or absence of certain organisms, or indicators, reveals much about the quality of the water. Some macroinvertebrates are sensitive to changes in water quality and are found more often, and in larger amounts, in waters that are generally clean, or unpolluted by organic wastes and having more oxygen. Other macroinvertebrates are not sensitive to pollution; therefore a large number of these can be an indicator of poor water quality.

Macroinvertebrate "Indicators" Students can use their macroinvertebrate identification reports and the lists below to make a statement about the quality of their pond water sample (e.g. The pond water was polluted because it contained mostly midgefly larvae and none of the indicators for good water quality).

  • Indicators of good water quality
    • Mayfly larvae
    • Caddisfly larvae
    • Stonefly larvae
    • Gilled snails (can be identified the operculum, a little "door" that protects the opening of the shell and can be closed quickly)
  • Indicators of fair water quality
    • Crayfish
    • Beetles
    • Dragonfly larvae
    • Cranefly larvae
    • Damselfly larvae
    • Scuds
  • Indicators of poor water quality
    • Midge fly larvae
    • Blackfly larvae
    • Leeches
    • Aquatic worms
    • Lung snails ( have no operculum to cover the shell opening)