🌊 Lea
eDNA Biodiversity Report Card
15 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 | 10 | 124 |
| Gobio gobio (Gudgeon) | Cyprinidae | 10 | 103 |
| Gasterosteus aculeatus (Three-spined Stickleback) | Gasterosteidae | 10 | 64 |
| Squalius cephalus (Chub) | Cyprinidae | 9 | 87 |
| Barbus barbus (Barbel) | Cyprinidae | 9 | 49 |
| Barbatula barbatula (Stone Loach) | Nemacheilidae | 9 | 40 |
| Cyprinus carpio (Common Carp) | Cyprinidae | 7 | 31 |
| Leuciscus leuciscus (Dace) | Cyprinidae | 6 | 45 |
| Salmo trutta (Brown Trout / Sea Trout) | Salmonidae | 5 | 14 |
| Carassius auratus (Goldfish) | Cyprinidae | 3 | 5 |
| Oncorhynchus gorbuscha (Pink Salmon) | Salmonidae | 1 | 1 |
| Oncorhynchus mykiss (Rainbow Trout) | Salmonidae | 1 | 1 |
| Species | Family | Sites | ESVs |
|---|---|---|---|
| Baetis rhodani (Large Dark Olive) | Baetidae | 10 | 23 |
| Serratella ignita (Blue Winged Olive) | Ephemerellidae | 7 | 23 |
| Caenis luctuosa (Angler's Curse) | Caenidae | 7 | 8 |
| Baetis vernus (Medium Olive) | Baetidae | 5 | 7 |
| Cloeon dipterum (Pond Olive) | Baetidae | 4 | 4 |
| Ephemera danica (The Mayfly) | Ephemeridae | 3 | 5 |
| Paraleptophlebia submarginata (Turkey Brown) | Leptophlebiidae | 2 | 4 |
| Baetis buceratus (Scarce Olive) | Baetidae | 2 | 2 |
| Baetis scambus (Small Dark Olive) | Baetidae | 1 | 3 |
| Procloeon pennulatum (Large Spurwing) | Baetidae | 1 | 1 |
| Ephemera vulgata (Drake Mackerel) | Ephemeridae | 1 | 1 |
| Habrophlebia fusca (Ditch Dun) | Leptophlebiidae | 1 | 1 |
| Species | Family | Sites | ESVs |
|---|---|---|---|
| Zwicknia bifrons (Small Winter Stonefly) | Capniidae | 1 | 4 |
| Nemoura erratica (Erratic Stonefly) | Nemouridae | 1 | 1 |
| Nemurella pictetii (Pictet's Stonefly) | Nemouridae | 1 | 1 |
| Isoperla grammatica (Yellow Sally) | Perlodidae | 1 | 1 |
| Species | Family | Sites | ESVs |
|---|---|---|---|
| Glyphotaelius pellucidus (Northern Caddisflies) | Limnephilidae | 9 | 39 |
| Lype phaeopa (Tube-case Caddisflies) | Psychomyiidae | 5 | 5 |
| Limnephilus marmoratus (Northern Caddisflies) | Limnephilidae | 3 | 5 |
| Hydroptila sparsa (Microcaddisflies) | Hydroptilidae | 2 | 3 |
| Phryganea grandis (Large Case-maker Caddisflies) | Phryganeidae | 2 | 3 |
| Goera pilosa (Humpless Case-maker Caddisflies) | Goeridae | 2 | 2 |
| Lepidostoma hirtum (Lepidostomatid Caddisflies) | Lepidostomatidae | 2 | 2 |
| Brachycentrus subnubilus (Humpless Case-maker Caddisflies) | Brachycentridae | 1 | 2 |
| Silo nigricornis (Humpless Case-maker Caddisflies) | Goeridae | 1 | 2 |
| Limnephilus extricatus (Northern Caddisflies) | Limnephilidae | 1 | 2 |
| Crunoecia irrorata (Lepidostomatid Caddisflies) | Lepidostomatidae | 1 | 1 |
| Micropterna lateralis (Northern Caddisflies) | Limnephilidae | 1 | 1 |
| Site | Location | Species | Genera | EPT Families | Notes |
|---|---|---|---|---|---|
| U7 | Mill Green | 305 | 214 | 6 | 🌟 |
| U3 | Meads (Wheathampstead) | 293 | 201 | 5 | |
| U6 | Stanborough South | 277 | 188 | 8 | |
| U8 | Waterhall Farm | 275 | 198 | 11 | |
| U5 | Lemsford Village | 269 | 181 | 5 | |
| U10 | Gaunts (downstream of Amwell M... | 265 | 185 | 8 | |
| U4 | Waterend Lane | 260 | 174 | 4 | |
| U2 | Batford Springs | 233 | 158 | 5 | |
| U1B | East Hyde | 208 | 149 | 4 | |
| U1A | Manor Road Park (upstream site... | 121 | 92 | 1 |
🌟 = Most diverse site on river
The Lea flows through the Upper Lea (Hertfordshire) catchment, where our eDNA survey sampled 10 sites along its length. Analysis of water samples revealed a rich invertebrate community with 717 distinct genetic sequences (Species) representing 715 identified species and 213 families.
Compared to other chalk streams surveyed, the Lea shows one of the most biodiverse rivers in the study, ranking #3 of 11. The river supports 15 families of mayflies, stoneflies, and caddisflies (EPT) - key indicators of water quality.
Notable findings include the detection of conservation priority species (Eurasian otter, Water vole) and invasive species requiring management attention.
717 Species detected across 10 sites — CSV format, opens in Excel
