Macroinvertebrate Survey of watercress farm outflows, Alresford , Autumn 2021

Macroinvertebrate Survey of watercress farm outflows, Alresford , Autumn 2021

Report prepared by Robert Aquilina MSc MCIEEM

October 2021

Macroinvertebrate survey of watercress farm outflows, Alresford, Autumn 2021

Robert Aquilina MSc MCIEEM

October 2021

Robert Aquilina MSc MCIEEM is an independent consulting ecologist specialising in protected species and freshwater ecology. He is a Full member of the Institute of Ecology and Environmental Management and abides by their Code of Professional Conduct. For further details see www.cieem.net www.aquilina-environmental.co.uk

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Table of contents

Summary .............................................................................................................. 4 Introduction .......................................................................................................... 5 Methods ............................................................................................................... 5 BMWP ............................................................................................................................................. 6 WHPT .............................................................................................................................................. 6 Locations ......................................................................................................................................... 7

Results ................................................................................................................. 10 Discussion ............................................................................................................ 12 References ........................................................................................................... 13 Appendix 1 Species recorded with abundance. ..................................................... 14

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Summary

Macroinvertebrate surveys of outflows from Bishop’s Sutton, above and below settlement ponds at Drayton Farm and Manor Farm watercress farms at Alresford, Hampshire were carried out using standard sampling techniques. The purpose was to repeat surveys undertaken in the autumn of 2019 and 2020 in order to investigate any changes and identify any potential water quality issues.

The species present were typical of a chalk stream, with good diversity and water quality scores. A complete list of species is presented together with abundance and diversity (WHPT) scores. All the significant indices had increased from the previous year, probably due to weather conditions as the changes appeared across all four sites.

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Introduction

The purpose of this survey was to repeat the assessments carried out in previous years of the discharges from the watercress beds at Bishop’s Sutton, Drayton and Manor Farm around Alresford and identify any impacts to biodiversity. The protocols followed were identical to those used previously and as such, this report follows the format of the previous report (Aquilina, 2020). Much of the descriptive material is retained from that report in order to facilitate understanding.

Drayton and Manor Farm are situated at the head of small chalk streams and use borehole water to supply the watercress beds which then is discharged into the stream. Bishop’s Sutton is located slightly further down the headwaters of another stream but is also fed by borehole water.

All three unnamed streams join the River Alre either directly (Manor Farm) or via Old Alresford Pond. The River Alre in turn joins the River Itchen, an important chalk stream for salmon and trout fishing and conservation.

Sampling at Drayton Farm was carried out above and below the main site as per previous sampling.

The Drayton sites were visited by Robert Aquilina on Tuesday 7th September 2021 and Manor Farm and Bishops Sutton on Wednesday 22nd September 2021. The dates follow those of the surveys from the previous year.

The weather conditions were dry and suitable for the survey with normal water flow levels.

Industry standard survey and extraction techniques for the stream (Environment Agency 2012) were used to assess the species present.

Methods The methodology followed is the standard Environment Agency survey and extraction protocol which results in a species list with abundance data. This forms the basis for calculating a number of indices designed to assess the impacts of various factors (depending on the index selected) but in this case is used to calculate the WHPT index (Walley Hawkes Paisley Trigg - river invertebrate index that is used as the basis for river invertebrate status classification for Water Framework Directive) .

Aquatic macroinvertebrates were collected using a standard size FBA D-frame pond net from the major habitats along the stream (stands of different wetland plants, distinctive substrates, tree roots etc.). All the different habitats present were allocated a proportion of the overall sampling time (3 minutes) and different areas of the same mesohabitat were subsampled to ensure that as great a range as possible was sampled.

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Each location was also searched for an additional minute looking for surface dwelling animals such as water skaters and whirligig beetles and inspecting submerged habitats such as logs and larger stones for attached animals.

The samples were preserved in 70% IMS and sorted in the laboratory, where all the invertebrates were extracted and counted. The standard BMWP invertebrate groups were recorded : Tricladida (flatworms), Gastropoda (snails and bivalves), Crustacea (slaters, shrimps and crayfish), Hirudinea (leeches), Megaloptera (alderflies), Plecoptera (stoneflies), Ephemeroptera (mayflies), Odonata (dragonflies and damselflies), Hemiptera (water bugs), Coleoptera (water beetles), Trichoptera (caddisflies) and Diptera (true flies). Voucher specimens were retained in order to check their identity.

Dead mollusc shells, and empty caddis cases were discarded and only whole animals were included in the counts.

BMWP Condition assessment of running waters is based on the BMWP (Biological Monitoring Working Party) score. These BMWP family scores (1-10) are industry standard and reflect the sensitivity of the families to pollution. The higher the family score, the more sensitive to oxygen depletion the family is and therefore their presence indicates a cleaner or less impacted site. The effects of pollution generally are to impose a Biological Oxygen Demand upon the receiving waters and so sensitive families are progressively excluded as the BOD increases.

The score for each family present is totalled to give a site score. Because these site BMWP scores are influenced by sample size (a high score can be achieved through a large number of low scoring families as well as a small number of high scoring families) an Average Score Per Taxa (ASPT) is also calculated from the resulting BMWP scores and allows further interpretation of the results. The higher the ASPT, the greater the proportion of more sensitive families in the sample and therefore the better the site condition.

WHPT WHPT better reflects the quality of the invertebrate community because it is based on a wider range of taxa (mostly families). In particular, WHPT includes more families of Diptera and some families that were grouped together in BMWP (known as BMWP composite taxa) are considered separately in WHPT. So 106 taxa are included in WHPT as opposed to the 82 in BMWP. Additionally the abundance of each taxa is taken into account through the use of abundance classes, the WHPT score for each taxa present depending on its abundance.

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Abundance category Numerical abundance AB1 1-9 AB2 10 -99 AB3 100 - 999 AB4 >1000 Table 1: WHPT abundance classes Apart from accounting for abundance, the calculation of scores is the same as for BMWP and results in equivalent but more accurate reflection of water quality. The scores derived are WHPT overall score (equivalent to BMWP), N taxa (number of taxa contributing to the score) and ASPT.

Locations All locations are as sampled in previous years and are described below with any changes in the habitat noted.

The Bishop’s Sutton outflow is located at SU 60400 32321.

The outflow channel is canalised and subject to fast deep flow. There is a gravel bed with strong Ranunculus growth but the banks are vertical stone with little vegetation. Therefore mesohabitats were limited to gravel, Ranunculus, marginal vegetation and the Fontinalis moss growing downstream of the weir. Sampling was concentrated in the Ranunculus which dominated the site (95% cover) to an even greater extent than the previous year.

Photo 1. Bishops Sutton.

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The Drayton Farm – below settlement ponds outflow was located at SU 59358 33272.

The sample reach was downstream of a bridge with culverts discharging the water, leading to scour in the channel bed. Substrate in this area was gravel with cobbles but was of limited extent. Further downstream, the substrate was fine and soft underfoot in the majority of the channel with some gravel reaches. Banks were earth but had little marginal vegetation. No in-channel vegetation was present presumably because of the shade from the trees.

Sampling was concentrated in the gravel and cobble area for 2 minutes and then upstream of the bridge for 1 minute in gravel.

Photo 2. Below Drayton Farm The Drayton Farm – above settlement ponds outflow was located at SU 59682 33310.

The channel is approximately 1 - 1.5 metres wide and 0.2 – 0.3 metres deep. Water flow is maintained by discharge from the borehole. The habitats present consisted of gravel, coarse and fine sands, Ranunculus beds and marginal Glyceria maxima with small amounts of other marginal plants. This represents the head of the stream as upstream are the watercress beds and borehole supply.

Ranunculus growth was reduced this year compared to gravel (40:60%) which appears to be a continuing trend from the domination by Ranunculus in 2019.

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Photo 3. Above Drayton Farm.

The Manor Farm outflow is located at SU 58532 33516.

The habitats present consisted of cobbles, small stone, gravel, coarse sand, with significant regrowth of marginal vegetation (Common reed, Watercress and Water Speedwell) similar to last year. Again there was very little in-channel Ranunculus.

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Photo 4. Manor Farm.

Results

The full species lists are presented as an appendix. The results summarised here consist of number of species, abundance and WHPT, N-taxa and ASPT for 2019, 2020 and 2021.

All the significant indices have increased this year compared with last year and compared with most of the 2019 results as well (only Manor Farm has a higher previous WHPT score from 2019). Overall abundance is generally down on previous years but this is a highly variable result and is not a significant measure of water quality or biodiversity. Overall number of species and number of contributing species (to the indices) have also increased (or remained the same in the case of Drayton Farm above settlement ponds ).

As a consequence, this years’ results are higher than the seasonal means so these have not been presented this year.

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Site

Date

Bishop’s Sutton

3/9/19 Autumn 15/9/20 Autumn 22/9/21 Autumn 3/9/19 Autumn

54 46 57 41

2488 3035 3252 918

38 32 41 31

201.9 161.8 225.4 160.8

5.31 5.06 5.50 5.19

7/9/20 Autumn 7/9/21 Autumn 22/8/18 Summer

40 48 46

1043 866 1966

34 38 32

175.0 198.2 149.4

5.15 5.22 4.67

3/9/19 Autumn 45 1242 33 7/9/20 Autumn 43 1772 35 7/9/21 Autumn 43 1281 35 3/9/19 Autumn 53 2699 38 15/9/20 Autumn 47 4894 35 22/9/21 Autumn 54 3332 38 Values showing an increase are highlighted in blue

165.4 160.8 168.2 211.6 174.0 200.8

5.01 4.59 4.81 5.57 4.97 5.28

Drayton Farm below settlement ponds

Drayton Farm above settlement ponds

Manor Farm

Season

# species

Abundance Ntaxa

WHPT ASPT

Table 2. Results summary

Because the increases are across all the sites, it is likely that favourable weather conditions will have contributed to the results, as well as the usual seasonal and sampling variations.

Much of the variation in species richness is contributed by single occurrences of species whereas most of the variation in abundance is due to variation of a small number of species.

Gammarus counts are summarised below and show a mix of responses across the sites which would be expected as there is no overall trend to the results year on year.

Site

Sept 2019 Sept 2020 Sept 2021

Bishop’s Sutton Drayton below settlement ponds Drayton above settlement ponds Manor Farm

928 364 159 1341

1606 440 580 3598

1708 139 127 1560

Table 3. Gammarus counts

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Discussion

The results illustrate the natural variation between years and, because the enhanced WHPT scores are across all sites, it is suspected to be due to the weather conditions and lack of vegetation removal rather than any significant change in water quality.

WHPT scores 240 220 200 180 160 140

Manor Farm

Above Drayton

Below Drayton

44409

44348

44287

44228

44166

44105

44044

43983

43922

43862

43800

43739

43678

43617

43556

43497

43435

43374

43313

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Bishops Sutton

Graph 1. Annual WHPT scores The relative cover of the habitats present at each site were all similar to the previous year and possibly reflect some constancy of environment which may have influenced scores positively.

Gammarus counts show no trend across sites.

Overall it is concluded that three factors are potentially reflected in the enhanced scores of 2021:  

Weather conditions that have been favourable (a cooler than average summer).

Vegetation removal (which significantly disturbs the invertebrate community) was not carried out this year.

Salad washing plant at Drayton Farm paused operation this year which might be expected to affect two of the survey sites but not the other two which are on separate streams.

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References Aquilina, R. (2019). Macroinvertebrate Survey of watercress farm outflows, Alresford, Hants.

Aquilina, R. (2020). Macroinvertebrate Survey of watercress farm outflows, Alresford, Autumn, 2020.

Clarke,R.T., Furse, M.T., Gunn, R.J.M., Winder, J.M. and Wright, J.F. (2002). Sampling variation in macroinvertebrate data and implications for river quality indices. Freshwater Biology 47, 1735-1751.

Environment Agency. (2012). Freshwater macro-invertebrate sampling in rivers. Operational instruction 018_08. Environment Agency.

Environment Agency. (2012). Freshwater macro-invertebrate analysis of riverine samples.

Operational instruction 024_08. Environment Agency.

Environment Agency. (2014). Walley Hawkes Paisley Trigg (WHPT) index of river invertebrate quality and its use in assesing ecological status. Brief Guide version 5.

Paisley,M.F., Trigg,D.J. and Walley,W.J. (2013). Revision of the Biological Monitoring Working Party (BMWP) score system: derivation of present-only and abundance-related scores from field data. River Research and Appications. 30: 887-904.

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Appendix 1 Species recorded with abundance.

Group

BMWP family

Species

Common name

Tricladida

Dendrocoelidae

Dendrocoelum lacteum

Flatworm

Tricladida

Dugesiidae

Dugesia polychroa gr.

Flatworm

Tricladida

Planariidae

Polycelis felina

Flatworm

Tricladida

Planariidae

Polycelis nigra

Flatworm

Tricladida

Planariidae

Polycelis tenuis

Flatworm

Mollusca

Hydrobiidae

Potamopyrgus antipodarum

Jenkins spire snail

Mollusca

Physidae

Physa fontinalis

Bladder snail

Mollusca

Lymnaeidae

Radix balthica

Wandering snail

Mollusca

Lymnaeidae

Stagnicola fuscus

Marsh Pond snail

Mollusca

Planorbidae

Anisus leucostoma

Button ramshorn

Mollusca

Planorbidae

Anisus vortex

Whirlpool ramshorn

Mollusca

Planorbidae

Bathyomphalus contortus

Twisted ramshorn

Mollusca

Planorbidae

Gyraulus albus

White ramshorn

Mollusca

Valvatidae

Valvata cristata

Flat valve snail

Mollusca

Valvatidae

Valvata piscinalis

Common valve snail

Mollusca

Ancylidae

Ancylus fluviatilis

River limpet

Mollusca

Sphaeridae

Pisidium sp.

Pea mussel

Crustacea

Asellidae

Asellus aquaticus

Water slater

Crustacea

Gammaridae

Gammarus pulex

Freshwater shrimp

Hirudinea

Erpobdellidae

Erpobdella octoculata

Leech

Status

Abundance

Bishops Sutton

3

=Lymnaea peregra

77 83 2 23

2 41 5 163 1708 61

Group

BMWP family

Species

Common name

Hirudinea

Erpobdellidae

Trocheta subviridis

Leech

Hirudinea

Glossiphonidae

Alboglossiphonia heteroclita

Leech

Hirudinea

Glossiphonidae

Glossiphonia complanata

Leech

Hirudinea

Glossiphonidae

Helobdella stagnalis

Leech

Hirudinea

Glossiphonidae

Theromyzon tessulatum

Duck leech

Hirudinea

Piscicolidae

Piscicola geometra

Fish leech

Plecoptera

Nemouridae

Nemurella picteti

Stonefly

Plecoptera

Leuctridae

Leuctra fusca

Stonefly

Plecoptera

Leuctridae

Leuctra nigra

Stonefly

Ephemeroptera

Ephemerellidae

Serratella ignita

Blue-winged Olive

Ephemeroptera

Baetidae

Baetis rhodani

Large Dark Olive

Ephemeroptera

Baetidae

Baetis vernus

Medium Olive

Ephemeroptera

Caenidae

Caenis sp.

Mayfly

Megaloptera

Sialidae

Sialis lutaria

Alderfly

Hemiptera

Gerridae

Gerris sp.

Water skater

Hemiptera

Veliidae

Velia caprai

Water cricket

Hemiptera

Corixidae

Sigara dorsalis

Lesser water boatman

Hemiptera

Corixidae

Coleoptera

Haliplidae

Brychius elevatus

Crawling water beetle

Coleoptera

Haliplidae

Haliplus lineatocollis

Crawling water beetle

Coleoptera

Haliplidae

Haliplus sp.

Crawling water beetle

Status

Abundance

1 3 38 6 1 2 1 9 279 246 early instars not identifiable to species

3

Lesser water boatman

15

nymph

nymph

2 9

larvae not identifiable to species

18

Group

BMWP family

Species

Common name

Coleoptera

Dytiscidae

Nebrioporus elegans

Diving beetle

Coleoptera

Dytiscidae

Oreodytes sanmarkii

Diving beetle

Coleoptera

Dytiscidae

Coleoptera

Hydrophilidae

Anacaena globulus

Water beetle

Coleoptera

Hydrophilidae

Laccobius bipunctatus

Water beetle

Coleoptera

Elmidae

Elmis aenea

Riffle beetle

larva and adults

Coleoptera

Elmidae

Limnius volckmari

Riffle beetle

larvae

Coleoptera

Elmidae

Riolus subviolaceus

Riffle beetle

larva and adults

Coleoptera

Scirtidae

Elodes sp.

Marsh beetle

larva

Trichoptera

Hydropsychidae

Diplectrona felix

Caseless caddis

Trichoptera

Hydropsychidae

Hydropsyche siltalai

Caseless caddis

Trichoptera

Polycentropodidae

Plectrocnema conspersa

Caseless caddis

Trichoptera

Rhyacophilidae

Rhyacophila dorsalis

Caseless caddis

Trichoptera

Glossosomatidae

Agapetus fuscipes

Saddle-case caddis

Trichoptera

Brachycentridae

Brachycentrus subnubilis

Cased caddis

Trichoptera

Hydroptilidae

Agraylea multipunctata

Cased caddis

Trichoptera

Hydroptilidae

Hydroptila sp.

Cased caddis

larvae not identifiable to species

Trichoptera

Hydroptilidae

Oxyethira sp.

Cased caddis

larvae not identifiable to species

Trichoptera

Beraeidae

Beraeodes minutus

Cased caddis

21 57 1

Trichoptera

Limnephilidae

Drusus annulatus

Cased caddis

Trichoptera

Limnephilidae

Potamophylax latipennis

Cased caddis

Trichoptera

Limnephilidae

pupa

Trichoptera

Goeridae

3 6 3

Diving beetle

Cased caddis Silo nigricornis

Cased caddis

16

Status

Abundance 4 18

larvae not identifiable to species

4 1 1 76 1 8 8 2

16 3

Group

BMWP family

Species

Common name

Status

Abundance

Trichoptera

Odontoceridae

Odontocerum albicorne

Silver sedge Biting midge

larvae

Non-biting midge

larvae

Meniscus midges

larvae

1 2 1 89 1

Trichoptera

Sericostomatidae

Sericostoma personatum

Cased caddis

Diptera

Ceratopogonidae

Diptera

Chironomidae

Diptera

Dixidae

Diptera

Ephydridae

Shore fly

pupa

Diptera

Empididae

Dance fly

larvae

Diptera

Muscidae

Limnophora riparia

Stable fly

larvae

Diptera

Psychodidae

Pericoma sp.

Moth fly

larvae

Diptera

Sciomyzidae

Snail-killing flies

Diptera

Simulidae

Simulium sp.

Blackflies

larvae early instars not identifiable to species

Diptera

Stratiomyidae

Oxycera sp.

Soldier fly

larvae

Diptera

Tipulidae

cranefly

larvae

Diptera

Tipulidae(Pediciidae)

cranefly

larvae

Others

Hydracarina

Water mite

Others

Oligochaeta

True worms

Dixa nebulosa

Dicranota sp.

17

17 8 5

60 4 3 1 8 33

Group

BMWP family

Species

Common name

Status

Abundance

Drayton Farm above settlement ponds Tricladida

Dendrocoelidae

Dendrocoelum lacteum

Flatworm

Tricladida

Dugesiidae

Dugesia polychroa gr.

Flatworm

Tricladida

Planariidae

Polycelis felina

Flatworm

Tricladida

Planariidae

Polycelis nigra

Flatworm

Tricladida

Planariidae

Polycelis tenuis

Flatworm

Mollusca

Physidae

Physa fontinalis

Bladder snail

Mollusca

Lymnaeidae

Galba truncatula

Dwarf pond snail

Mollusca

Lymnaeidae

Stagnicola palustris

Marsh snail

=Lymnaea palustris

Mollusca

Lymnaeidae

Radix balthica

Wandering snail

=Lymnaea peregra

Mollusca

Planorbidae

Anisus leucostoma

Button ramshorn

Mollusca

Planorbidae

Anisus vortex

Whirlpool ramshorn

Mollusca

Planorbidae

Bathyomphalus contortus

Twisted ramshorn

Mollusca

Planorbidae

Gyraulus crista

Nautilus ramshorn

Mollusca

Planorbidae

Hippeutis complanata

Flat ramshorn

Mollusca

Valvatidae

Valvata cristata

Flat valve snail

Mollusca

Valvatidae

Valvata piscinalis

Valve snail

Mollusca

Ancylidae

Ancylus fluviatilis

River limpet

Mollusca

Sphaeridae

Pisidium sp.

Pea mussel

Crustacea

Asellidae

Asellus aquaticus

Water slater

Crustacea

Niphargidae

Niphargus aquilex

Cave shrimp

Crustacea

Gammaridae

Gammarus pulex

Freshwater shrimp

Hirudinea

Erpobdellidae

Erpobdella octoculata

Leech

18

1

2 1

37

3 8 1 1 5 127 18

Group

BMWP family

Species

Common name

Hirudinea

Erpobdellidae

Trocheta subviridis

Leech

Hirudinea

Glossiphonidae

Glossiphonia complanata

Leech

Hirudinea

Glossiphonidae

Helobdella stagnalis

Leech

Hirudinea

Glossiphonidae

Theromyzon tessulatum

Duck leech

Hirudinea

Piscicolidae

Piscicola geometra

Fish leech

Ephemeroptera

Ephemerellidae

Serratella ignita

Blue-winged Olive

Ephemeroptera

Baetidae

Baetis rhodani

Large Dark Olive

Ephemeroptera

Baetidae

Baetis vernus

Medium Olive

Ephemeroptera

Baetidae

Cloeon dipterum

Pond olive

Ephemeroptera

Caenidae

Caenis rivulorum

Mayfly

Ephemeroptera

Ephemeridae

Ephemera danica

Greendrake

Plecoptera

Nemouridae

Nemurella picteti

Stonefly

Plecoptera

Nemouridae

Nemoura cinerea

Stonefly

Megaloptera

Sialidae

Sialis lutaria

Alderfly

Hemiptera

Corixidae

Sigara dorsalis

Lesser water boatman

Hemiptera

Gerridae

Gerris sp.

Water skater

Hemiptera

Veliidae

Velia caprai

Water cricket

Coleoptera

Haliplidae

Brychius elevatus

Crawling water beetle

Coleoptera

Haliplidae

Haliplus lineatocollis

Crawling water beetle

Coleoptera

Haliplidae

Haliplus sibiricus

Crawling water beetle

Coleoptera

Haliplidae

Haliplus sp.

Crawling water beetle

Coleoptera

Dytiscidae

Nebrioporus elegans

Diving beetle

Coleoptera

Dytiscidae

Oreodytes sanmarkii

Diving beetle

Status

Abundance

4 43

19

17 224 79

1

3 nymph

1

larvae not identifiable to species

14

Group

BMWP family

Species

Common name

Status

Coleoptera

Dytiscidae

Diving beetle

larvae not identifiable to species

Coleoptera

Hydrophilidae

Anacaena limbata

Scavenger water beetle

Coleoptera

Hydrophilidae

Helophorus brevipalpis

Scavenger water beetle

Coleoptera

Hydrophilidae

Coleoptera

Elmidae

Coleoptera

Scavenger water beetle

larvae not identifiable to species

Elmis aenea

Riffle beetle

larva and adults

Elmidae

Limnius volckmari

Riffle beetle

larva and adults

Coleoptera

Elmidae

Riolus subviolaceus

Riffle beetle

larva and adults

Coleoptera

Scirtidae

Microcara testacea

Marsh beetle

larva

Trichoptera

Hydropsychidae

Hydropsyche siltalai

Caseless caddis

Trichoptera

Psychomyiidae

Tinodes waeneri

Caseless caddis

Trichoptera

Rhyacophilidae

Rhyacophila dorsalis

Caseless caddis

Trichoptera

Glossosomatidae

Agapetus fuscipes

Saddle-case caddis

Trichoptera

Hydroptilidae

Hydroptila sp.

Cased caddis

Trichoptera

Hydroptilidae

Oxyethira sp.

Cased caddis

Trichoptera

Leptoceridae

Adicella reducta

Long-horned caddis

Trichoptera

Limnephilidae

Anabola nervosa

Cased caddis

Trichoptera

Limnephilidae

Drusus annulatus

Cased caddis

Trichoptera

Limnephilidae

Halesus digitatus

Cased caddis

Trichoptera

Limnephilidae

Limnephilus lunatus

Cased caddis

Trichoptera

Limnephilidae

Melampophylax mucoreus

Cased caddis

Trichoptera

Limnephilidae

Micropterna lateralis

Cased caddis

20

Abundance

11

2 6 1

1 13 larvae not identifiable to species larvae not identifiable to species

33 62

6

Group

BMWP family

Species

Common name

Trichoptera

Limnephilidae

Potamophylax latipennis

Cased caddis

Trichoptera

Limnephilidae

Trichoptera

Goeridae

Silo nigricornis

Cased caddis

Trichoptera

Odontoceridae

Odontocerum albicorne

Silver sedge

Trichoptera

Sericostomatidae

Sericostoma personatum

Cased caddis

Diptera

Anthomyzidae

Diptera

Ceratopogonidae

Biting midge

larvae

Diptera

Chironomidae

Non-biting midge

larvae

Diptera

Culicidae

Mosquito

larvae

Diptera

Dixidae

Dixa nebulosa

Meniscus midge

larvae

Diptera

Empididae

Clinocera sp.

Dance fly

larvae

Diptera

Ephydridae

Setacera sp.

Shore fly

larvae

Diptera

Muscidae

Limnophora riparia

Stable fly

larvae

Diptera

Psychodidae

Pericoma sp.

Moth fly

larvae

Diptera

Sciomyzidae

Snail-killing flies

Diptera

Simulidae

Blackflies

larvae early instars not identifiable to species

Diptera

Stratiomyidae

Soldier fly

larvae

Diptera

Syrphidae

Hover fly

larvae

Diptera

Tipulidae

cranefly

larvae

Diptera

Tipulidae (Limoniidae)

cranefly

larvae

Diptera

Tipulidae(Pediciidae)

cranefly

larvae

Others

Hydracarina

Water mite

Others

Oligochaeta

True worms

Cased caddis

Status

Abundance

early instars not identifiable to species

larvae

Simulium sp.

Dicranota sp.

21

8 314 17 6 14 1 4 17 1 36

8 4 16 110

Group

BMWP family

Species

Common name

Status

Abundance

Drayton Farm below settlement ponds Tricladida

Dendrocoelidae

Dendrocoelum lacteum

Flatworm

Tricladida

Dugesiidae

Dugesia polychroa gr.

Flatworm

Tricladida

Planariidae

Polycelis felina

Flatworm

Tricladida

Planariidae

Polycelis nigra

Flatworm

Tricladida

Planariidae

Polycelis tenuis

Flatworm

Mollusca

Physidae

Physa fontinalis

Bladder snail

Mollusca

Lymnaeidae

Galba truncatula

Dwarf pond snail

Mollusca

Lymnaeidae

Radix balthica

Wandering snail

Mollusca

Planorbidae

Anisus leucostoma

Button ramshorn

Mollusca

Planorbidae

Anisus vortex

Whirlpool ramshorn

Mollusca

Planorbidae

Bathyomphalus contortus

Twisted ramshorn

Mollusca

Planorbidae

Gyraulus crista

Nautilus ramshorn

Mollusca

Planorbidae

Hippeutis complanata

Flat ramshorn

Mollusca

Valvatidae

Valvata cristata

Flat valve snail

Mollusca

Valvatidae

Valvata piscinalis

Valve snail

Mollusca

Ancylidae

Ancylus fluviatilis

River limpet

Mollusca

Sphaeridae

Pisidium sp.

Pea mussel

Crustacea

Asellidae

Asellus aquaticus

Water slater

Crustacea

Niphargidae

Niphargus aquilex

Cave shrimp

Crustacea

Gammaridae

Gammarus pulex

Freshwater shrimp

Hirudinea

Erpobdellidae

Erpobdella octoculata

Leech

22

1

=Lymnaea peregra

2 1 1 2 2 32 1

6 12 14 139 8

Group

BMWP family

Species

Common name

Hirudinea

Erpobdellidae

Trocheta subviridis

Leech

Hirudinea

Glossiphonidae

Glossiphonia complanata

Leech

Hirudinea

Glossiphonidae

Helobdella stagnalis

Leech

Hirudinea

Glossiphonidae

Theromyzon tessulatum

Duck leech

Hirudinea

Piscicolidae

Piscicola geometra

Fish leech

Plecoptera

Leuctridae

Leuctra fusca

Stonefly

Plecoptera

Leuctridae

Leuctra geniculata

Stonefly

Plecoptera

Nemouridae

Nemurella picteti

Stonefly

Ephemeroptera

Ephemerellidae

Serratella ignita

Blue-winged Olive

Ephemeroptera

Baetidae

Baetis rhodani

Large Dark Olive

Ephemeroptera

Baetidae

Baetis vernus

Medium Olive

Ephemeroptera

Caenidae

Caenis rivulorum

Mayfly

Ephemeroptera

Ephemeridae

Ephemera danica

Greendrake

Megaloptera

Sialidae

Sialis lutaria

Alderfly

Odonata

Calopterygidae

Calopteryx virgo

Beautiful demoiselle

Hemiptera

Corixidae

Sigara dorsalis

Lesser water boatman

Hemiptera

Gerridae

Gerris sp.

Water skater

Hemiptera

Veliidae

Velia caprai

Water cricket

Coleoptera

Haliplidae

Brychius elevatus

Crawling water beetle

Coleoptera

Haliplidae

Haliplus lineatocollis

Crawling water beetle

Coleoptera

Haliplidae

Haliplus sibiricus

Crawling water beetle

Coleoptera

Haliplidae

Haliplus sp.

Crawling water beetle

Coleoptera

Dytiscidae

Oreodytes sanmarkii

Diving beetle

Status

Abundance

30 4

23

1 1 1 7 51 113

4 1 nymph

1 2

larvae not identifiable to species

5 7

Group

BMWP family

Coleoptera

Dytiscidae

Coleoptera

Hydrophilidae

Anacaena globulus

Scavenger water beetle

Coleoptera

Hydrophilidae

Helophorus brevipalpis

Scavenger water beetle

Coleoptera

Elmidae

Elmis aenea

Riffle beetle

larva and adults

Coleoptera

Elmidae

Limnius volckmari

Riffle beetle

larva and adults

Coleoptera

Elmidae

Riolus subviolaceus

Riffle beetle

larva and adults

Coleoptera

Scirtidae

Microcara testacea

Marsh beetle

larva

Trichoptera

Hydropsychidae

Hydropsyche siltalai

Caseless caddis

Trichoptera

Psychomyiidae

Lype reducta

Caseless caddis

Trichoptera

Rhyacophilidae

Rhyacophila dorsalis

Caseless caddis

Trichoptera

Glossosomatidae

Agapetus fuscipes

Saddle-case caddis

Trichoptera

Hydroptilidae

Hydroptila sp.

Cased caddis

larvae not identifiable to species

Trichoptera

Hydroptilidae

Oxyethira sp.

Cased caddis

larvae not identifiable to species

Trichoptera

Leptoceridae

Adicella reducta

Long-horned caddis

Trichoptera

Beraeidae

Beraeodes minutus

Cased caddis

Trichoptera

Limnephilidae

Anabola nervosa

Cased caddis

Trichoptera

Limnephilidae

Drusus annulatus

Cased caddis

Trichoptera

Limnephilidae

Halesus digitatus

Cased caddis

Trichoptera

Limnephilidae

Limnephilus lunatus

Cased caddis

Trichoptera

Limnephilidae

Melampophylax mucoreus

Cased caddis

Trichoptera

Limnephilidae

Micropterna lateralis

Cased caddis

Trichoptera

Limnephilidae

Potamophylax latipennis

Cased caddis

Trichoptera

Limnephilidae

Species

Common name

Status

Diving beetle

larvae not identifiable to species

Cased caddis

24

Abundance 2

102 1

1 2 5 6 11

13 7 early instars not identifiable to species

Group

BMWP family

Species

Common name

Status

Abundance

Trichoptera

Goeridae

Silo nigricornis

Cased caddis

Trichoptera

Odontoceridae

Odontocerum albicorne

Silver sedge

Trichoptera

Sericostomatidae

Sericostoma personatum

Cased caddis

Diptera

Anthomyzidae

Diptera

Ceratopogonidae

Biting midge

larvae

Diptera

Chironomidae

Non-biting midge

larvae

Diptera

Dixidae

Meniscus midge

larvae

Diptera

Ephydridae

Shore flies

pupae

Diptera

Muscidae

Limnophora riparia

Stable fly

pupae

Diptera

Psychodidae

Pericoma sp.

Moth fly

larvae

1 1

Diptera

Sciomyzidae

Snail-killing flies

Diptera

Simulidae

Simulium sp.

Blackflies

larvae early instars not identifiable to species

76

Diptera

Stratiomyidae

Oxycera nigricornis

Delicate Soldier fly

larvae

Diptera

Tipulidae

cranefly

larvae

Diptera

Tipulidae (Limoniidae)

cranefly

larvae

Diptera

Tipulidae(Pediciidae)

cranefly

larvae

Others

Hydracarina

Water mite

Others

Oligochaeta

True worms

2 larvae

Dixa nebulosa

Dicranota sp.

25

6 29 2

1

4 40 105

Group

BMWP family

Species

Common name

Status

Tricladida

Dendrocoelidae

Dendrocoelum lacteum

Flatworm

Tricladida

Dugesiidae

Dugesia polychroa gr.

Flatworm

Tricladida

Planariidae

Polycelis felina

Flatworm

Tricladida

Planariidae

Polycelis nigra gr.

Flatworm

Tricladida

Planariidae

Polycelis tenuis

Flatworm

Mollusca

Physidae

Physa fontinalis

Bladder snail

Mollusca

Lymnaeidae

Galba truncatula

Dwarf pond snail

=Lymnaea truncatula

Mollusca

Lymnaeidae

Radix balthica

Wandering snail

=Lymnaea peregra

Mollusca

Lymnaeidae

Stagnicola palustris

Marsh snail

=Lymnaea palustris

Mollusca

Planorbidae

Anisus leucostoma

Button ramshorn

Mollusca

Planorbidae

Anisus vortex

Whirlpool ramshorn

Mollusca

Planorbidae

Bathyomphalus contortus

Twisted ramshorn

Planorbidae

Planorbarius corneus

Great ramshorn

Mollusca

Valvatidae

Valvata cristata

Flat valve snail

Mollusca

Valvatidae

Valvata piscinalis

Common valve snail

Mollusca

Ancylidae

Acroloxus lacustris

Lake limpet

Mollusca

Ancylidae

Ancylus fluviatilis

River limpet

Mollusca

Sphaeridae

Sphaerium corneum

Horny orb mussel

Mollusca

Sphaeridae

Pisidium sp.

Pea mussel

Crustacea

Asellidae

Asellus aquaticus

Water slater

Crustacea

Gammaridae

Gammarus pulex

Freshwater shrimp

Abundance

Manor Farm

26

7 3 1 8 34 12 42 23 7 1 17 4 79 1 6 297 1560

Group

BMWP family

Species

Common name

Status

Abundance

Hirudinea

Erpobdellidae

Erpobdella octoculata

Leech

Hirudinea

Erpobdellidae

Trocheta subviridis

Leech

Hirudinea

Glossiphonidae

Glossiphonia complanata

Leech

Hirudinea

Glossiphonidae

Helobdella stagnalis

Leech

Hirudinea

Glossiphonidae

Theromyzon tessulatum

Duck leech

Hirudinea

Piscicolidae

Piscicola geometra

Fish leech

Plecoptera

Leuctridae

Leuctra fusca

Stonefly

Plecoptera

Nemouridae

Nemurella picteti

Stonefly

10

Ephemeroptera

Ephemerellidae

Serratella ignita

Blue-winged Olive

15

Ephemeroptera

Baetidae

Baetis rhodani

Large Dark Olive

Ephemeroptera

Baetidae

Baetis vernus

Medium Olive

Ephemeroptera

Caenidae

Caenis luctuosa

Mayfly

Ephemeroptera

Caenidae

Caenis rivulorum

Mayfly

Ephemeroptera

Ephemeridae

Ephemera danica

Greendrake

Ephemeroptera

Heptageniidae

Rithrogena semicolorata

Olive upright

Megaloptera

Sialidae

Sialis lutaria

Alderfly

Hemiptera

Gerridae

Gerris sp.

Water skater

nymph

Hemiptera

Veliidae

Velia caprai

Water cricket

nymph

Hemiptera

Corixidae

Water boatman

nymph

Coleoptera

Haliplidae

Haliplus lineatocollis

Crawling water beetle

Coleoptera

Haliplidae

Haliplus sp.

Crawling water beetle

Coleoptera

Dytiscidae

Oreodytes sanmarkii

Diving beetle

Coleoptera

Elmidae

Elmis aenea

Riffle beetle

81 14 17 2

319 60 3 1 2

27

larvae not identifiable to species

3

larva and adults

39

Group

BMWP family

Species

Common name

Status

Abundance

Coleoptera

Elmidae

Limnius volckmari

Riffle beetle

larvae

3

Coleoptera

Elmidae

Riolus sp.

Riffle beetle

larvae

Coleoptera

Scirtidae

Elodes sp.

Marsh beetle

larva

Trichoptera

Hydropsychidae

Diplectrona felix

Caseless caddis

Trichoptera

Hydropsychidae

Hydropsyche siltalai

Caseless caddis

Trichoptera

Rhyacophilidae

Rhyacophila dorsalis

Caseless caddis

Trichoptera

Glossosomatidae

Agapetus fuscipes

Saddle-case caddis

Trichoptera

Hydroptilidae

Agraylea sexmaculata

Cased caddis

Trichoptera

Hydroptilidae

Hydroptila sp.

Cased caddis

larvae not identifiable to species

Trichoptera

Hydroptilidae

Ithytrichia sp.

Cased caddis

larvae not identifiable to species

Trichoptera

Hydroptilidae

Oxyethira sp.

Cased caddis

larvae not identifiable to species

Trichoptera

Leptoceridae

Adicella reducta

Long-horned caddis

Trichoptera

Limnephilidae

Cased caddis

Trichoptera

Limnephilidae

Limnephilus lunatus Melampophylax mucoreus

Trichoptera

Limnephilidae

Potamophylax latipennis

Cased caddis

Trichoptera

Limnephilidae

Trichoptera

Goeridae

Silo nigricornis

Cased caddis

Trichoptera

Odontoceridae

Odontocerum albicorne

Silver sedge

Trichoptera

Sericostomatidae

Sericostoma personatum

Cased caddis

Diptera

Ceratopogonidae

Biting midge

larvae

Diptera

Chironomidae

Non-biting midge

larvae

Diptera

Dixidae

Meniscus midges

larvae

Diptera

Empididae

Dance fly

larvae

Dixa sp.

28

86

1 1

Cased caddis

Cased caddis

5 5 49 1 43

early instars not identifiable to species

2 30 4 11 15 114 1 1

Group

BMWP family

Diptera

Ephydridae

Diptera

Muscidae

Diptera

Psychodidae

Diptera

Sciomyzidae

Diptera

Simulidae

Diptera

Species

Common name

Status

Shore fly

pupa and larva

Stable fly

pupa and larva

5

Moth fly

larvae

8

Snail-killing flies Blackflies

larvae early instars not identifiable to species

82

Stratiomyidae

Soldier fly

larvae

Diptera

Tipulidae

cranefly

larvae

Diptera

Tipulidae(Pediciidae)

Dicranota sp.

cranefly

larvae

Diptera

Tipulidae(Pediciidae)

Pedicia sp.

cranefly

larvae

Others

Hydracarina

Water mite

Others

Oligochaeta

True worms

Limnophora riparia Pericoma sp. + Psychoda sp.

Simulium ornatum gr.

Abundance

1 8 11 177

29