River Restoration
Cracking the code October 2006
BMWP scores for the River Wandle at Carshalton
| Family | Numbers at date 1 | Numbers at date 2 | Common name | BMWP scoring |
| 04/04/05 | 11/10/05 | |||
| Ephemerellidae | 2 | 2 | Blue winged olive | 10 |
| Sericostomatidae | 2 | 25 | Welshman's Button sedge | 10 |
| Leptoceridae | 3 | 130 | Grousewing or silverhorn sedge | 10 |
| Psychomyiidae | 0 | 1 | Small red sedge | 8 |
| Glossosomatidae | 180 | 130 | Micro (caseless) caddis | 7 |
| Limnephilidae | 8 | 0 | Cinnamon sedge | 7 |
| Ancylidae | 1 | 40 | Snail | 6 |
| Gammaridae | 1000 | 310 | Freshwater shrimp | 6 |
| Haliplidae | 1 | 0 | Water beetle | 5 |
| Elmidae | 13 | 25 | Riffle beetle | 5 |
| Planariidae | 3 | 3 | Flatworm | 5 |
| Baetidae | 5 | 10 | Large dark olive or spurwing | 4 |
| Valvatidae | 3 | 100 | Snail | 3 |
| Hydrobiidae | 23 | 210 | Snail | 3 |
| Physidae | 0 | 15 | Snail | 3 |
| Lymnaeidae | 0 | 2 | Snail | 3 |
| Planorbidae | 1 | 40 | Snail | 3 |
| Sphaeridae | 1 | 45 | Pea mussel | 3 |
| Glossiphoniidae | 10 | 4 | Leech | 3 |
| Erpobdellidae | 10 | 30 | Leech | 3 |
| Asellidae | 18 | 50 | Water hoglouse | 3 |
| Chironomidae | 1 | 40 | Midge | 2 |
| Oligochaeta | 120 | 100 | Annelid worm | 1 |
| Hydracarina | 4 | 40 | Water mite | 0 |
| Ostracoda | 1 | 0 | Water flea | 0 |
| Muscidae | 0 | 1 | Fly (diptera) | 0 |
| Veliidae | 0 | 1 | Water strider | 0 |
| Ceratopogonidae | 1 | 3 | Biting midge | 0 |
| BMWP score | 99 | 101 | ||
| ASPT value | 4.95 | 4.81 | ||
| Scoring taxa | 20 | 21 |
Notes:
Only the first 3 columns, plus the fifth by extrapolation, will normally appear in the BMWP data available from the EA
Next month, I'll reveal the scores you can use to put together your own version of this chart.