1. How healthy is the water?12
How healthy is the water?
Why count creatures?
You can use invertebrates to tell how healthy water is.
Ones that breathe through gills like Dragonfly Nymphs find it hard to live in polluted water as there is less oxygen.
Invertebrates that use an air bubble such as water beetles can cope with less oxygen in the water as they get their air from the surface.
Dragonfly nymph
Type of Pond Animal
Quality Index
Score
Cased caddis fly larvae
Score 10 if found
Dragonfly larvae
Score 10 if found
Alderfly larvae
Damselfly larvae
Caseless Cadisfly larvae
Mayfly larvae
Score 5 if found
Water beetles/ larvae
Score 5 if found
Waterbugs
Pond skaters
Water shrimps
Water snails
Score 1 if found
Hoglouse
Score 1 if found
Worm like animals
Total score=
Water boatman
What does your score mean for the water?
Score 31 or more
Very healthy
Score 6-30
Quite healthy
Score 0-5
Not very healthy