📍 A10: Holycross road (downstream site)

River: Ash Catchment: Upper Lea (Hertfordshire) Filter(s): 61

Your Site at a Glance

131
Species Detected
102
Genera Identified
66
Families Found
688,432
DNA Sequences

How Your Site Compares

Metric Your Site Ash Average Study Average
Species 131 211 206
Genera 102 159 151
Families 66 93 83
EPT Families 7 9 6

Rank 7 of 7 on Ash Rank 65 of 81 in study

🌊 Water Quality Indicators

Good

BMWP score: 91 (Good) — ASPT score: 6.1 (Excellent)

15 scoring macroinvertebrate families detected

Clean water with slight impacts; a healthy community of macroinvertebrate families is present.

🔍 Notable Findings

Conservation Species:

Invasive Species:

🦋 Top 10 Families at Your Site

1. Chironomidae (Non-biting Midges)
35 (26.7%)
2. Naididae (Aquatic Oligochaetes)
10 (7.6%)
3. Cyprinidae (Carp and Allies)
7 (5.3%)
4. Simuliidae (Black Flies)
5 (3.8%)
5. Baetidae (Small Mayflies)
3 (2.3%)
6. Lumbricidae (Common Earthworms)
2 (1.5%)
7. Ephemeridae (Burrowing Mayflies)
2 (1.5%)
8. Julidae (Cylindrical Millipedes)
2 (1.5%)
9. Cyclopidae (Cyclopoid Copepods)
2 (1.5%)
10. Muscidae (House Flies)
2 (1.5%)
Taxonomic composition

🪲 Extended Riverfly Taxa

1 Flatworms 18Dragonflies and Damselflies
2 Freshwater Snails 19Water Boatmen
3 Limpets 20Other Water Bugs
4 Bivalves 21Water Beetles
5 Aquatic Worms 22Alderflies
6 Leeches 23Caseless Caddisflies - Green Sedge
7 Crayfish 24Caseless Caddisflies - Net Spinners
8 Water Hoglouse 25Caseless Caddisflies - Non-Gilled
9 Freshwater Shrimps 26Cased Caddisflies - Hood Case-Maker
10 Invasive Non-Native Shrimps 27Cased Caddisflies - Weighted Case-Maker
11 Mayflies - Angler's Curse 28Cased Caddisflies - Bush Tailed Caddisfly
12 Mayflies - Olives 29Cased Caddisflies - Other
13 Mayflies - Prong Gilled 30Craneflies
14 Mayflies - Flatbodied 31Blackflies
15 Mayflies - Green Drake 32Non-Biting Midges
16 Mayflies - Blue-Winged Olive 33Water Snipe Flies
17 Stoneflies
16/33 Extended Riverfly taxa detected

Note: The Extended Riverfly Monitoring Initiative calculates scores based on abundance categories, which cannot be determined from eDNA presence/absence data. This checklist shows which taxa groups were detected but does not constitute an official ARMI score.

🐟 Fish Species

12 fish species detected (5 families, 51 ESVs)
SpeciesFamilyESVs
Leuciscus leuciscus (Dace) Cyprinidae 8
Phoxinus phoxinus (Minnow) Cyprinidae 8
Squalius cephalus (Chub) Cyprinidae 4
Salmo trutta (Brown Trout / Sea Trout) Salmonidae 3
Thymallus aeliani Salmonidae 2
Barbatula barbatula (Stone Loach) Nemacheilidae 2
Rutilus frisii Cyprinidae 2
Cottus bairdii Cottidae 1
Gobio kovatschevi Cyprinidae 1
Gobio gobio (Gudgeon) Cyprinidae 1
Squalius alburnoides Cyprinidae 1
Gasterosteus aculeatus (Three-spined Stickleback) Gasterosteidae 1

🪰 EPT Species (Mayflies, Stoneflies & Caddisflies)

10 EPT species detected (7 families, 19 ESVs — E:7 / P:0 / T:3)
SpeciesFamilyESVs
Ephemeroptera (Mayflies)
Paraleptophlebia submarginata (Turkey Brown) Leptophlebiidae 4
Baetis vernus (Medium Olive) Baetidae 3
Baetis rhodani (Large Dark Olive) Baetidae 2
Ephemera danica (The Mayfly) Ephemeridae 2
Ephemera vulgata (Drake Mackerel) Ephemeridae 2
Procloeon pennulatum (Large Spurwing) Baetidae 1
Caenis luctuosa (Angler's Curse) Caenidae 1
Trichoptera (Caddisflies)
Hydroptila sparsa (Microcaddisflies) Hydroptilidae 2
Silo nigricornis (Humpless Case-maker Caddisflies) Goeridae 1
Glyphotaelius pellucidus (Northern Caddisflies) Limnephilidae 1

🔗 Your Ecological Twin

Most similar site: A9 - Watersplace Farm
River: Ash (same river)
Similarity: 40% of species shared
Download Data

131 Species detected at this site — CSV format, opens in Excel

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