This document outlines a biotic index activity to analyze three river samples using images of invertebrates from each sample to estimate water quality at different sites. Students are asked to determine the biotic index value and water quality for each of three sample sites: one upstream of a farm, one next to the farm, and one 500 meters downstream, and suggest an explanation for any differences.

1. Biotic Index Activity
Analyse the three samples to estimate river quality
using a biotic index

2. Method
• Kick samples were taken from the
three sites as shown on the map
• Images of invertebrates in each
sample are shown
• Analyse these samples using the
Biotic index sheet

3. Kick Sample 1 – River upstream of farm

4. Kick Sample 2 – River next to farm

5. Kick Sample 3 – River 500m downstream

6. Results / Conclusion
• What is the Biotic Index value for
each site?
• What is the water quality of each site
• Suggest an explanation.