Pollution Indicator species
by John Brennan
1. Sleeford Pollution
1.1. Snapshot was no use
1.2. Lots of dead fish
1.3. Silt pollution
2. Lichens
2.1. Alga and fungus
2.2. Sensitive to SO2
3. Freshwater Invertebrates
3.1. Varied tolerance
4. Tolerance
5. Idea of indicators
6. Chemical tests
6.1. Dissolved Oxygen
6.2. SO2
6.3. Chemical snapshot
