Indicator Species
by John Brennan
1. Clean water
1.1. Stonefly larva
1.2. Water snipe fly
1.3. Alderfly
2. Polluted Water
2.1. Sludgeworm
2.2. Rat tailed Maggot
2.3. Bloodworm
3. Medium Pollution
3.1. Mayfly Larva
3.2. Freshwater Mussel
3.3. Damselfly Larva
