Group 1 --Highly Sensitive to Pollution: Stonefly 
Dobsonfly 
Group 2 --Semi-Sensitive to Pollution: Caddisfly 
Dragonfly 
Waterpenny 
Crawfish 
Cranefly 
Damselfly 
Mayfly 
Group 3 -- Semi-Tolerant of Pollution: Orb Snail 
Scud 
Group 4 -- Tolerant of Pollution: Sowbug 
Leech 
Tubefix worm 
Pouch Snail 
You have just dredged a specified area of the streambed using a kicknet :) Carefully drag the leaves and rocks away to reveal macroinvertebrates. Using the guide above, segregate macros into different types near the margins of the kicknet. Count the number of types (not number of individuals) per pollution tolerance Group, then submit the raw data and simple calculated values into the table below to determine a snapshot of overall stream health.
| Group 1: |
| Types = (a) x 4 = (b) |
| Group 2: |
| Types = (a) x 3 = (b) |
| Group 3: |
| Types = (a) x 2 = (b) |
| Group 4: |
| Types = (a) x 1 = (b) |
| Total Types (sum of a) = |
| Total Value (sum of b) = |
| Total Value (b) ÷ Total Types (a) = |
This is the Index Score, which is a wholistic measure of the overall health of the stream.
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