🌊 Ash
eDNA Biodiversity Report Card
14 EPT families
Outstanding diversity of pollution-sensitive invertebrates indicating pristine water quality.
Top 15 families detected by eDNA analysis:
| Species | Family | Sites | ESVs |
|---|---|---|---|
| Phoxinus phoxinus (Minnow) | Cyprinidae | 7 | 45 |
| Salmo trutta (Brown Trout / Sea Trout) | Salmonidae | 7 | 33 |
| Gasterosteus aculeatus (Three-spined Stickleback) | Gasterosteidae | 7 | 32 |
| Squalius cephalus (Chub) | Cyprinidae | 5 | 21 |
| Barbatula barbatula (Stone Loach) | Nemacheilidae | 5 | 10 |
| Leuciscus leuciscus (Dace) | Cyprinidae | 3 | 26 |
| Gobio gobio (Gudgeon) | Cyprinidae | 2 | 2 |
| Species | Family | Sites | ESVs |
|---|---|---|---|
| Paraleptophlebia submarginata (Turkey Brown) | Leptophlebiidae | 7 | 22 |
| Baetis rhodani (Large Dark Olive) | Baetidae | 7 | 14 |
| Habrophlebia fusca (Ditch Dun) | Leptophlebiidae | 6 | 22 |
| Ephemera danica (The Mayfly) | Ephemeridae | 6 | 11 |
| Baetis vernus (Medium Olive) | Baetidae | 5 | 11 |
| Baetis scambus (Small Dark Olive) | Baetidae | 5 | 8 |
| Serratella ignita (Blue Winged Olive) | Ephemerellidae | 5 | 7 |
| Ephemera vulgata (Drake Mackerel) | Ephemeridae | 3 | 5 |
| Caenis luctuosa (Angler's Curse) | Caenidae | 3 | 3 |
| Centroptilum luteolum (Small Spurwing) | Baetidae | 1 | 2 |
| Procloeon pennulatum (Large Spurwing) | Baetidae | 1 | 1 |
| Species | Family | Sites | ESVs |
|---|---|---|---|
| Leuctra fusca (Late Needle Fly) | Leuctridae | 6 | 27 |
| Leuctra digitata (Rolled-winged Stoneflies) | Leuctridae | 6 | 13 |
| Species | Family | Sites | ESVs |
|---|---|---|---|
| Glyphotaelius pellucidus (Northern Caddisflies) | Limnephilidae | 7 | 14 |
| Silo nigricornis (Humpless Case-maker Caddisflies) | Goeridae | 7 | 7 |
| Hydroptila sparsa (Microcaddisflies) | Hydroptilidae | 4 | 8 |
| Limnephilus extricatus (Northern Caddisflies) | Limnephilidae | 3 | 6 |
| Halesus radiatus (Northern Caddisflies) | Limnephilidae | 3 | 5 |
| Hydroptila vectis (Microcaddisflies) | Hydroptilidae | 3 | 3 |
| Notidobia ciliaris (Sericostomatid Caddisflies) | Sericostomatidae | 3 | 3 |
| Silo pallipes (Humpless Case-maker Caddisflies) | Goeridae | 2 | 3 |
| Lepidostoma hirtum (Lepidostomatid Caddisflies) | Lepidostomatidae | 2 | 3 |
| Chaetopteryx villosa (Northern Caddisflies) | Limnephilidae | 2 | 3 |
| Halesus digitatus (Northern Caddisflies) | Limnephilidae | 2 | 2 |
| Lype phaeopa (Tube-case Caddisflies) | Psychomyiidae | 2 | 2 |
| Goera pilosa (Humpless Case-maker Caddisflies) | Goeridae | 1 | 1 |
| Athripsodes albifrons (Long-horned Caddisflies) | Leptoceridae | 1 | 1 |
| Leptocerus tineiformis (Long-horned Caddisflies) | Leptoceridae | 1 | 1 |
| Limnephilus rhombicus (Northern Caddisflies) | Limnephilidae | 1 | 1 |
| Potamophylax latipennis (Northern Caddisflies) | Limnephilidae | 1 | 1 |
| Phryganea bipunctata (Large Case-maker Caddisflies) | Phryganeidae | 1 | 1 |
| Site | Location | Species | Genera | EPT Families | Notes |
|---|---|---|---|---|---|
| A4 | Malting Lane (upstream site) | 302 | 222 | 7 | 🌟 |
| A7 | Hoghams | 249 | 184 | 9 | |
| A6 | Widford STW Upstream | 242 | 183 | 10 | |
| A9 | Watersplace Farm | 215 | 164 | 11 | |
| A8 | Watersplace US | 205 | 155 | 11 | |
| A5 | Hadham Mill | 131 | 105 | 8 | |
| A10 | Holycross road (downstream sit... | 131 | 102 | 7 |
🌟 = Most diverse site on river
The Ash flows through the Upper Lea (Hertfordshire) catchment, where our eDNA survey sampled 7 sites along its length. Analysis of water samples revealed a rich invertebrate community with 584 distinct genetic sequences (Species) representing 583 identified species and 202 families.
Compared to other chalk streams surveyed, the Ash shows moderate diversity compared to other rivers in the study (#6 of 11). The river supports 14 families of mayflies, stoneflies, and caddisflies (EPT) - key indicators of water quality.
Notable findings include the detection of conservation priority species (Water vole, Water shrew) and invasive species requiring management attention.
584 Species detected across 7 sites — CSV format, opens in Excel
