Table 1 OPAL Water Survey invertebrate classification and ‘Invertebrate group health’ score based on the tolerance of the group to a range of stressors. Below is a comparison of descriptors for the derived pond health score ranges for the OPAL Water Survey (2010) and the 2014 Big Pond Dip [54]
From: Quality control in public participation assessments of water quality: the OPAL Water Survey
Tolerance class | Groups | Group health score |
|---|---|---|
High sensitivity | Cased caddisfly larvae; Caseless caddisfly larvae; Dragonfly larvae; Damselfly larvae; Alderfly larvae | 10 |
Medium sensitivity | Mayfly larvae; Water beetles (adults and larvae); Water bugs (including water boatmen, water scorpions, water stick insects etc.,); Pond skaters; Water shrimps | 5 |
Low sensitivity | Water slaters (water hoglice); Worm-like animals (including chironomid larvae; flatworms; leeches; worms etc.,); Water snails (spired; limpets; planorbids) | 1 |
Pond health score | OPAL Water Survey (2010) description | Big Pond Dip (2014) description |
|---|---|---|
0–5 | Poor or ‘could be improved’ | Not yet great |
6–30 | Quite healthy | Good |
31 and above | Very healthy | Brilliant |