Macroinvertebrate survey of three watercress farm outflows Alresford Hants May 2019

Macroinvertebrate Survey of watercress farm outflows, Alresford , Hants 2019

Report prepared by Robert Aquilina MSc MCIEEM

June 2019

Macroinvertebrate survey of watercress farm outflows, Alresford, Hants 2019

Robert Aquilina MSc MCIEEM

June 2019

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 .............................................................................................................................................. 7 Locations ......................................................................................................................................... 7

Results ................................................................................................................. 11 Conclusions .......................................................................................................... 13 References ........................................................................................................... 13 Appendix 1 Species recorded. ............................................................................... 15

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Summary

Macroinvertebrate surveys of outflows from Bishop’s Sutton, above and below Drayton Farm and Manor Farm watercress farms at Alresford, Hampshire were carried out using standard sampling techniques. The purpose was to repeat surveys a year on 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. Changes in the indices (ASPT) appear to reflect normal variation in sampling efficacy and natural environmental variation.

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Introduction

The purpose of this survey was to repeat the assessments of a year ago 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, 2018). 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 May and August 2018 sampling.

The sites were visited by Robert Aquilina on Tuesday 28th May 2019 and samples were collected for analysis in the laboratory using standard techniques. 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 standard BMWP and its more sophisticated modification WHPT. 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

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the same mesohabitat were subsampled to ensure that as great a range as possible was sampled.

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. 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.

The only difference between the method used in 2018 and 2019 was that in 2018, samples were sorted live which allowed flatworms to be identified to species level. In 2019, because the number of samples had increased to four, processing time would have extended beyond the ability to keep the samples fresh and live and so were all preserved immediately. The only effect that this would have, is on the separation of flatworm species which are reported as species groups and consequently give a slight reduction in number of species for 2019.

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.

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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.

Abundance category Numerical abundance AB1 AB2 AB3 AB4

1-9 10 -99 100 - 999 >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 and ASPT.

Locations All locations are as sampled in 2018 and are described below. New photographs are supplied and any changes in the habitat are 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 and gravel.

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Photograph 1: Bishop’s Sutton outflow 2019

The below Drayton 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.

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Photograph 2: below Drayton outflow 2019

The above Drayton 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.

Significant increases in Ranunculus growth had occurred between 2018 and 2019 leaving much less gravel exposed. Therefore sampling was concentrated in the Ranunculus.

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Photograph 3: above Drayton outflow 2019

The Manor Farm outflow is located at SU 58532 33516.

The habitats present consisted of cobbles, small stone, gravel, coarse sand, with almost no in-channel and limited marginal vegetation in contrast to 2018. The landowner appears to have cleared the vegetation to improve flow.

A tree had fallen across the stream close to the discharge point which was now shading the immediate outfall area. Sampling was restricted to shaded gravel with cobbles near the discharge and sunny gravel below the fallen tree. Some Ranunculus was sampled together with a small amount of marginal Veronica (Water speedwell).

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Photograph 4: Manor Farm outflow.

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 2018 and 2019. These are presented by site as well as by index for comparative purposes.

The significant measure of water quality is the ASPT score. This is because gross scores such as abundance or WHPT are heavily influenced by sampling bias and would be expected to vary on every occasion to some extent. To overcome such bias the Average Score Per Taxon (ASPT) is calculated which reflects more accurately the water quality with higher scores representing less impact.

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Site

Date

# species Abundance N-taxa WHPT ASPT

Bishop’s Sutton

22/5/18 28/5/19 Below Drayton Farm 22/5/18 28/5/19 Above Drayton Farm 22/8/18 28/5/19 Manor Farm 22/5/18 28/5/19

49 31 47 40 46 39 53 39

1237 1478 813 1165 1966 1809 1675 2515

35 27 34 31 32 29 38 34

194.6 139.3 174.8 154.3 149.4 146.9 204.8 186.5

N-taxa (WHPT) 27 31 29 34

ASPT (BMWP) 5.00 5.04 4.96 5.71

5.56 5.16 5.14 4.98 4.67 5.07 5.39 5.49

Table 2. Results summary

Site

BMWP

Bishop’s Sutton Below Drayton Above Drayton Manor Farm

130 131 124 177

WHPT N-taxa (BMWP) 139.3 26 154.3 26 146.9 25 186.5 31

ASPT (WHPT) 5.16 4.98 5.07 5.49

Table 3. BMWP v WHPT results comparison 2019 The results show a confusing mix of changes but the important index is ASPT which has increased at Manor Farm and above Drayton and decreased at the other two sites which leads to the interpretation that no trend is being seen but normal variation in sampling efficiency and natural year on year fluctuation. Overall the number of species captured at each site has declined (although part of that decline is due to the grouping of flatworm species previously separated). Overall abundance has increased at three of the sites.

Much of the variation in species richness is contributed by single occurrences of species whereas most of the variation in abundance is due to much greater numbers of mayflies this year compared with 2018. Gammarus counts are summarised below but also show an increase at two sites and a decrease at the other two (curiously the opposite sites to ASPT increases).

Site

2018 2019

Bishop’s Sutton Below Drayton Above Drayton Manor Farm

323 91 223 638

405 243 115 272

Table 5. Gammarus counts 12

Worthy of comment are the presence of two new species in 2019. Melampophylax mucoreus is a caddis fly of Local distribution, typical of chalk streams and other base rich waters. Niphargus aquilex is a crustacean related to Gammarus but found in groundwaters, caves and springs where it gets washed out into the main body of a watercourse by heavy rains and is occasionally found in gravels during kick sampling.

Conclusions It is too early to expect any trends to show up as there are only two data points collected so far. The results indicate a confusing mix of changes which are best summarised as two sites showing increased ASPT score and two decreased. This pattern is matched by Gammarus counts, albeit at different sites.

Overall it is concluded that two factors are the major influence on these results: Normal variation in sampling efficiency which has been suggested as representing 9 – 12 % between experienced practitioners (Clarke et al., 2002).  Natural year on year variation in abundance and species presence. In particular, the very different weather conditions between 2017 and 2019 is likely to have had an effect, albeit ameliorated by the constant temperature and flow rate from the borehole as a water source.

Repeated sampling should begin to build a dataset robust enough to separate the above effects from any longer term trends.

References Aquilina, R. (2018). Macroinvertebrate Survey of three watercress farm outflows, Alresford, Hants.

Aquilina, R. (2018). Macroinvertebrate Survey of Drayton watercress farm outflow, Alresford, Hants.

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.

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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 abundancerelated scores from field data. River Research and Appications. 30: 887-904.

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Appendix 1 Species recorded.

Group

BMWP family

Species

Common name

Notes

Abundance

Tricladida

Planariidae

Polycelis nigra gr.

Flatworm

Mollusca

Hydrobiidae

Potamopyrgus antipodarum

Jenkins spire snail

5

Mollusca

Physidae

Physa fontinalis

Bladder snail

Mollusca

Lymnaeidae

Lymnaea palustris

Marsh 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

Valvatidae

Valvata cristata

Flat valve snail

Mollusca

Valvatidae

Valvata piscinalis

Common valve snail

Mollusca

Ancylidae

Ancylus fluviatilis

River limpet

41

Crustacea

Asellidae

Asellus aquaticus

Water slater

88

Crustacea

Gammaridae

Gammarus pulex

Freshwater shrimp

Hirudinea

Erpobdellidae

Erpobdella octoculata

Leech

Hirudinea

Erpobdellidae

Trocheta subviridis

Leech

Hirudinea

Glossiphonidae

Glossiphonia complanata

Hirudinea

Glossiphonidae

Helobdella stagnalis

BMWP

WHPT

Bishops Sutton

1

5 3 3

5.4 4.1 2.7

35

3

2.5

5

3

3.2

1

34

3 6 3 6 3

3.3 5.5 2.3 4.6 2.0

Leech

1

3

3.4

Leech

4

29

=Lymnaea peregra

405

Group

BMWP family

Species

Common name

Notes

Abundance

Hirudinea

Glossiphonidae

Theromyzon tessulatum

Duck leech

Hirudinea

Piscicolidae

Piscicola geometra

Fish leech

Plecoptera

Nemouridae

Nemurella picteti

Stonefly

Ephemeroptera

Ephemerellidae

Serratella ignita

Blue-winged Olive

Ephemeroptera

Baetidae

Baetis rhodani

Large Dark Olive

202

Ephemeroptera

Baetidae

Baetis vernus

Medium Olive

303

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

Dytiscidae

Oreodytes sanmarkii

Diving beetle

Coleoptera

Elmidae

Elmis aenea

Riffle beetle

larva and adults

Coleoptera

Elmidae

Limnius volckmari

Riffle beetle

larvae

3

Coleoptera

Elmidae

Riolus subviolaceus

Riffle beetle

larvae

24

Coleoptera

Scirtidae

Microcara testacea

Marsh beetle

larva

Trichoptera

Hydropsychidae

Caseless caddis

Trichoptera

Polycentropodidae

Hydropsyche siltalai Polycentropus flavomaculatus

Trichoptera

Rhyacophilidae

Rhyacophila dorsalis

Caseless caddis

Trichoptera

Glossosomatidae

Agapetus fuscipes

Saddle-case caddis

BMWP

WHPT

10 4

8.5 7.2

2

5

3.4

1

5 5

4.5 8.3

16

5

7.2

6

7 7

8.1 7.8

6 7

6.5 6.9

75

nymph

82

Caseless caddis

Trichoptera

Hydroptilidae

Hydroptila sp.

Cased caddis

Trichoptera

Limnephilidae

Drusus annulatus

Cased caddis

Trichoptera

Limnephilidae

Limnephilus lunatus

Cased caddis

Trichoptera

Limnephilidae

Potamophylax latipennis

Cased caddis

16

4 larvae not identifiable to species

18 2

Group

BMWP family

Species

Common name

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

Ephydridae

Shore fly

pupa

Diptera

Psychodidae

Moth fly

larvae

Diptera

Sciomyzidae

Snail-killing flies

Diptera

Simulidae

Blackflies

larvae early instars not identifiable to species

Diptera

Stratiomyidae

Soldier fly

larvae

Diptera

Tipulidae

cranefly

larvae

Diptera

Tipulidae(Pediciidae)

cranefly

larvae

Others

Hydracarina

Water mite

Others

Oligochaeta

True worms

Simulium sp.

Notes

# taxa Score ASPT

17

Abundance

BMWP

WHPT

1

10

8.8

4

10

8.9

34

2

1.3 4.5

1

26

5

6.1

25

1

2.3

31 1478

26 130 5.00

27.0 139.3 5.16

Group

BMWP family

Species

Common name

Tricladida

Planariidae

Polycelis nigra gr.

Flatworm

Mollusca

Physidae

Physa fontinalis

Bladder snail

Mollusca

Lymnaeidae

Radix balthica

Wandering snail

Mollusca

Planorbidae

Anisus leucostoma

Button ramshorn

Mollusca

Planorbidae

Whirlpool ramshorn

Mollusca

Planorbidae

Anisus vortex Bathyomphalus contortus

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

Mollusca

Sphaeridae

Crustacea

Status

Abundance

BMWP

WHPT

Below Drayton

4

5

4.7

45

3

2.5

20

3

3.0

1

3

3.3

River limpet

57

6

5.5

Pisidium sp.

Pea mussel

27

3

3.5

Asellidae

Asellus aquaticus

Water slater

3

Crustacea

Niphargidae

Niphargus aquilex

Cave shrimp

Crustacea

Gammaridae

Gammarus pulex

Freshwater shrimp

Hirudinea

Erpobdellidae

Erpobdella octoculata

Leech

23 2 243 5

3

2.3 6.3 4.6 3.6

Hirudinea

Erpobdellidae

Leech

Hirudinea

Glossiphonidae

Trocheta subviridis Glossiphonia complanata

3

2.5

Hirudinea

Glossiphonidae

Helobdella stagnalis

Leech

30 5

Hirudinea

Glossiphonidae

Theromyzon tessulatum

=Lymnaea peregra

Twisted ramshorn

Leech

18

3

6

Group

BMWP family

Species

Common name

Status

Abundance

Ephemeroptera

Ephemerellidae

Serratella ignita

Blue-winged Olive

Ephemeroptera

Baetidae

Baetis rhodani

Large Dark Olive

25

Ephemeroptera

Baetidae

Baetis vernus

Medium Olive

Ephemeroptera

Caenidae

Caenis rivulorum

Mayfly

Ephemeroptera

Ephemeridae

Ephemera danica

Greendrake

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

Dytiscidae

Oreodytes sanmarkii

Diving beetle

Coleoptera

Hydrophilidae

Anacaena globulus

Scavenger water beetle

Coleoptera

Hydrophilidae

Helophorus brevipalpis

Scavenger water beetle

Coleoptera

Elmidae

Elmis aenea

Riffle beetle

Coleoptera

Elmidae

Limnius volckmari

Coleoptera

Elmidae

Riolus subviolaceus

Coleoptera

Scirtidae

Trichoptera

Hydropsychidae

Trichoptera

171

BMWP

WHPT

10

9.0

17

4

5.9

2 1 1 2

7

6.5 8.3 4.2 3.7

10 4 5

nymph

1

4.5

4

5

4.5

larva and adults

379

5

8.3

Riffle beetle

larva and adults

11

Riffle beetle

larva and adults

Microcara testacea

Marsh beetle

larva

Hydropsyche siltalai

Caseless caddis

4

5

5.8

Psychomyiidae

Lype reducta

Caseless caddis

Trichoptera

Rhyacophilidae

Rhyacophila dorsalis

Caseless caddis

1

7

8.1

Trichoptera

Glossosomatidae

Agapetus fuscipes

Saddle-case caddis

4

6

6.5

Trichoptera

Hydroptilidae

Hydroptila sp.

Cased caddis

19

larvae not identifiable to species

Group

BMWP family

Species

Common name

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

Cased caddis

Trichoptera

Limnephilidae

Limnephilus lunatus Melampophylax mucoreus

Trichoptera

Limnephilidae

Micropterna lateralis

Cased caddis

Trichoptera

Limnephilidae

Potamophylax latipennis

Cased caddis

Cased caddis

Cased caddis

Status

Abundance

1 1 17 Local

BMWP

WHPT

7

6.9

10

8.9

5

early instars not identifiable to species

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

1

Diptera

Chironomidae

Non-biting midge

larvae

11

Diptera

Dixidae

Meniscus midge

larvae

Diptera

Ephydridae

Shore flies

pupae

Diptera

Psychodidae

Moth fly

larvae

Diptera

Sciomyzidae

Snail-killing flies

1

3.4

Diptera

Simulidae

Blackflies

larvae early instars not identifiable to species

Diptera

Stratiomyidae

Soldier fly

larvae

1

3.6

Diptera

Tipulidae

cranefly

larvae

1

4 larvae

Dixa nebulosa Pericoma sp.

Simulium sp.

20

5.4 2

1.3

Group

BMWP family

Species

Diptera

Tipulidae (Limoniidae)

Diptera

Tipulidae(Pediciidae)

Others

Hydracarina

Water mite

Others

Oligochaeta

True worms

Dicranota sp.

Common name

Status

cranefly

larvae

1

cranefly

larvae

1

5

5.4

32

1

2.3

40 1165

26 131 5.04

31.0 154.3 4.98

# taxa Score ASPT

21

Abundance

BMWP

WHPT

Group

BMWP family

Species

Common name

Tricladida

Planariidae

Polycelis nigra gr.

Flatworm

Mollusca

Physidae

Physa fontinalis

Bladder snail

Mollusca

Lymnaeidae

Radix balthica

Wandering snail

Mollusca

Planorbidae

Anisus leucostoma

Button ramshorn

Mollusca

Planorbidae

Whirlpool ramshorn

Mollusca

Planorbidae

Anisus vortex Bathyomphalus contortus

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

Hirudinea

Erpobdellidae

Leech

Hirudinea

Glossiphonidae

Trocheta subviridis Glossiphonia complanata

Hirudinea

Glossiphonidae

Helobdella stagnalis

Leech

Hirudinea

Glossiphonidae

Theromyzon tessulatum

Status

Abundance

BMWP

WHPT

Above Drayton

=Lymnaea peregra

14

5

5.4

75

3

2.5

5

3

3.2

3

3.1

6 3 3

5.8 4.4 4.0

115 64

6 3

4.5 2.0

2 68

3

2.5

Twisted ramshorn

Leech

22

3 2 10 3 1 6

Group

BMWP family

Species

Common name

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

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

Dytiscidae

Oreodytes sanmarkii

Diving beetle

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

23

Status

Abundance

BMWP

WHPT

61 165 659 1

10

8.5

4 7

7.2 6.5

64

5

4.8

1 79

5 5

5.8 7.4

1 15

7 7

8.1 7.6

131

6

6.8

nymph

larvae not identifiable to species

1

Group

BMWP family

Species

Common name

Status larvae not identifiable to species

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

Cased caddis

Trichoptera

Limnephilidae

Limnephilus lunatus Melampophylax mucoreus

Trichoptera

Limnephilidae

Micropterna lateralis

Cased caddis

Trichoptera

Limnephilidae

Potamophylax latipennis

Cased caddis

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

Psychodidae

Moth fly

larvae

Diptera

Sciomyzidae

Snail-killing flies

Diptera

Simulidae

Blackflies

larvae early instars not identifiable to species

Diptera

Stratiomyidae

Soldier fly

larvae

Diptera

Tipulidae

cranefly

larvae

Abundance

BMWP

WHPT

39

2 4 4

7

5.9

21

10

9.4

2

5.4 1.3

Cased caddis

larvae

Dixa nebulosa Pericoma sp.

Simulium sp.

24

4 23 3 10

115 6 1

4.4 3.3

5 5

5.8 3.6 5.4

Group

BMWP family

Species

Tipulidae (Limoniidae) Dicranota sp.

Common name

Status

cranefly

larvae

cranefly

larvae

Diptera

Tipulidae(Pediciidae)

Others

Hydracarina

Water mite

Others

Oligochaeta

True worms

# taxa Score ASPT

25

Abundance

2 1 28 39 1809

BMWP

WHPT

1

2.3

25 124 4.96

29.0 146.9 5.07

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

Physidae

Physa fontinalis

Bladder snail

Mollusca

Lymnaeidae

Radix balthica

Wandering snail

Mollusca

Planorbidae

Anisus leucostoma

Button ramshorn

Mollusca

Planorbidae

Whirlpool ramshorn

Mollusca

Planorbidae

Anisus vortex Bathyomphalus contortus

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

Hirudinea

Erpobdellidae

Leech

Hirudinea

Glossiphonidae

Trocheta subviridis Glossiphonia complanata

Hirudinea

Glossiphonidae

Helobdella stagnalis

Leech

Hirudinea

Glossiphonidae

Theromyzon tessulatum

Status

Abundance

BMWP

WHPT

Manor Farm

=Lymnaea peregra

2

5

3.0

47

5

5.4

1 11 4 22

3 3 3

2.7 2.5 3

17 1 26 10 58 272 40

3

3.1

6 3 3 6 3

5.5 3.5 2.3 4.6 2.0

7 1

3

3.4

Twisted ramshorn

Leech

26

Group

BMWP family

Species

Common name

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 luctuosa

Mayfly

Ephemeroptera

Caenidae

Caenis rivulorum

Mayfly

Ephemeroptera

Ephemeridae

Ephemera danica

Greendrake

Ephemeroptera

Heptageniidae

Rithrogena semicolorata

Olive upright

Hemiptera

Gerridae

Gerris sp.

Water skater

nymph

Hemiptera

Veliidae

Velia caprai

Water cricket

nymph

Coleoptera

Haliplidae

Haliplus sibiricus

Crawling water beetle

Coleoptera

Dytiscidae

Oreodytes sanmarkii

Diving beetle

Coleoptera

Elmidae

Elmis aenea

Riffle beetle

larva and adults

Coleoptera

Elmidae

Limnius volckmari

Riffle beetle

larvae

Coleoptera

Scirtidae

Microcara testacea

Marsh beetle

larva

Trichoptera

Hydropsychidae

Hydropsyche siltalai

Caseless caddis

Trichoptera

Rhyacophilidae

Rhyacophila dorsalis

Caseless caddis

Trichoptera

Glossosomatidae

Agapetus fuscipes

Saddle-case caddis

Trichoptera

Hydroptilidae

Agraylea sp.

Cased caddis

Trichoptera

Hydroptilidae

Hydroptila sp.

Cased caddis

Trichoptera

Leptoceridae

Adicella reducta

Long-horned caddis

Trichoptera

Limnephilidae

Limnephilus lunatus

Cased caddis

Trichoptera

Limnephilidae

Potamophylax latipennis

Cased caddis

Trichoptera

Goeridae

Silo nigricornis

Cased caddis

27

Status

Abundance

1 126 1262 97

larvae not identifiable to species

BMWP

WHPT 7

8.7

10

9.0

4

7.5

42 2 2 1 1

7 10 10 5

6.5 8.3 8.5 5.2 4.5

62 1

5

7.4

27 4

5 7

7.2 8.1

2 1

6 10

6.1 6.7

1 2

7 10

5.9 8.8

Group

BMWP family

Species

Common name

Trichoptera

Odontoceridae

Odontocerum albicorne

Silver sedge

Trichoptera

Sericostomatidae

Sericostoma personatum

Cased caddis

Diptera

Ceratopogonidae

Biting midge

larvae

Diptera

Chironomidae

Non-biting midge

larvae

Diptera

Ephydridae

Shore fly

pupa and larva

Diptera

Muscidae

Limnophora riparia

Stabel fly

pupa

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

Tipulidae

cranefly

larvae

Diptera

Tipulidae(Pediciidae)

cranefly

larvae

Others

Hydracarina

Water mite

Others

Oligochaeta

True worms

Simulium sp.

Dicranota sp.

Status

# taxa Score ASPT

28

Abundance

4 5 8 141

BMWP

WHPT

10 10 2

4

11.1 8.9 5.4 -0.9

4.5

187

5

5.8

13

1

2.3

39 2515

31 177 5.71

34.0 186.5 5.49