Insects as Bioindicators of Water Quality
Data Sheet
Order
Family
Tolerance
Number
Family
Score
Order
Score
Steps:
1. Determine the Family Tolerance Score
2. Determine the Order Totals
3. Determine the Grand Total
4. Determine the Biotic Index
5. Estimate the stream water
quality rating
Biotic Index table
Biotic Index
0.00-3.75
3.76-4.25
4.26-5.00
5.01-5.75
5.76-6.50
6.51-7.25
7.26-10.0
Water Quality Rating
Excellent
Very Good
Good
Fair
Fairly Poor
Poor
Very Poor
Degree of Organic Pollution
Organic Pollution Unlikely
Slight Organic Pollution Possible
Some Organic Pollution Probable
Fairly Substantial Pollution Likely
Substantial Pollution Likely
Very Substantial Pollution Likely
Severe Organic Pollution Likely