Macroinvertebrate survey of three watercress farm outflows Alresford Hants September 2019.pdf

Macroinvertebrate Survey of watercress farm outflows, Alresford , Autumn 2019

Report prepared by Robert Aquilina MSc MCIEEM

October 2019

Macroinvertebrate survey of watercress farm outflows, Alresford, Autumn 2019

Robert Aquilina MSc MCIEEM

October 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 .................................................................................................................. 9 Conclusions .......................................................................................................... 11 References ........................................................................................................... 12 Appendix 1 Species recorded. ............................................................................... 13

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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 undertaken in the spring 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. Comparison is made with results from May 2019 as well as May 2018. Changes appear to be within normal variation in sampling efficacy and natural seasonal variation.

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Introduction

The purpose of this survey was to repeat the assessments carried out earlier in the year 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, 2019). 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 sites were visited by Robert Aquilina on Tuesday 3rd September 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 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, 5

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.

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. This was the same as for the May 2019 samples.

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 6

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.

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 May 2019 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 and gravel.

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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.

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.

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 after the vegetation clearance to improve flow prior to the May 2019 sampling. There was only limited recovery of in-channel Ranunculus.

The tree that had fallen across the stream close to the discharge point appears to be surviving and sending up shoots from the main trunk.

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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.

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.

Site

Date

Bishop’s Sutton

22/5/18

Below Drayton Farm

Above Drayton Farm

Manor Farm

Season

# species

Abundance Ntaxa

Spring

49

1237

35

194.6

5.56

28/5/19 Spring 3/9/19 Autumn 22/5/18 Spring

31 54 47

1478 2488 813

27 38 34

139.3 201.9 174.8

5.16 5.31 5.14

28/5/19 Spring 3/9/19 Autumn 22/8/18 Summer

40 41 46

1165 918 1966

31 31 32

154.3 160.8 149.4

4.98 5.19 4.67

146.9 165.4 204.8 186.5 211.6

5.07 5.01 5.39 5.49 5.57

28/5/19 Spring 39 1809 29 3/9/19 Autumn 45 1242 33 22/5/18 Spring 53 1675 38 28/5/19 Spring 39 2515 34 3/9/19 Autumn 53 2699 38 Values showing an increase are highlighted in blue

WHPT ASPT

Table 2. Results summary

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The results show an increase in 12 out of the 16 values. However care must be taken in interpreting this as the sampling took place in a different season and strictly speaking only the results of the same season are comparable.

Differences appear to be within the normal variation in sampling efficiency and natural seasonal fluctuation. Overall the number of species captured at each site has increased but overall abundance has increased at only half 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 variation of a small number of species. Gammarus counts are summarised below and show an increase at all sites from May 2019 and at three sites from May 2018 numbers. Strictly speaking comparison should only be made between the same season as there will be a natural rhythm to the population size through the year.

Site

May 2018* May 2019 Sept 2019

Bishop’s Sutton Below Drayton Above Drayton* Manor Farm Except * August 2018

323 91 223 638

405 243 115 272

928 364 159 1341

Table 3. Gammarus counts

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Conclusions It is too early to expect any trends to show up as there are only three data points collected so far and only two are in comparable seasons. The results suggest an increase in diversity scores and species richness generally but must not be taken too literally because of the difference in season that the samples were collected in.

This increase is matched by Gammarus counts but the same proviso applies.

The longest run of sampling has occurred at the Manor Farm site where an initial visit in 2016 allows for some exploration of the variation in results over time which is graphed below. This illustrates the natural variation between seasons and years.

Sep-19

Jul-19

May-19

Mar-19

Jan-19

Nov-18

Sep-18

Jul-18

May-18

Mar-18

Jan-18

Nov-17

Sep-17

Jul-17

May-17

Mar-17

Jan-17

215 210 205 200 195 190 185 180 175 170

Nov-16

WHPT

Manor Farm

Date

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. Weather patterns and weed growth (and management) are likely to be major influences.

Repeated sampling should begin to build a dataset robust enough to separate the above effects from any longer term trends and would ideally cover spring and autumn seasons, as initiated.

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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.

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

Tricladida

Dendrocoelidae

Dendrocoelum lacteum

Flatworm

Tricladida

Planariidae

Polycelis tenuis gr.

Flatworm

Mollusca

Physidae

Physa fontinalis

Bladder 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 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

Hirudinea

Glossiphonidae

Glossiphonia complanata

Leech

Hirudinea

Glossiphonidae

Glossiphonia heteroclita

Leech

Notes

Abundance

BMWP

WHPT

6 169 6 30 7 7 1 1 1 1 69 1 434 928 59 5 2

5 5 3 3

3.0 5.4 2.7 2.5

3

3.0

3 6 3 3 6 3

3.3 5.5 4.4 0.8 4.6 2.0

Bishops Sutton

=Lymnaea peregra

Group

BMWP family

Species

Common name

Hirudinea

Glossiphonidae

Helobdella stagnalis

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

Hemiptera

Corixidae

Sigara dorsalis

Lesser water boatman

Coleoptera

Haliplidae

Brychius elevatus

Crawling water beetle

Notes

larvae not identifiable to species

Coleoptera

Haliplidae

Haliplus sp.

Crawling water beetle

Coleoptera

Dytiscidae

Nebrioporus elegans

Diving beetle

Coleoptera

Dytiscidae

Oreodytes sanmarkii

Diving 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

Rhyacophilidae

Rhyacophila dorsalis

Caseless caddis

Trichoptera

Brachycentridae

Brachycentrus subnubilis

Cased caddis

Trichoptera

Glossosomatidae

Agapetus fuscipes

Saddle-case caddis

Trichoptera

Hydroptilidae

Agraylea multipunctata

Cased caddis

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Abundance

BMWP

WHPT

45 4 1 1 1 3 12 137 9 2

3 4 7

2.5 5.2 8.7

10 10

9.3 7.9

4 5

7.2 3.7

5

3.4

5

4.8

5

8.3 6.9

5 7 10 7

7.2 9.2 9.6 7.6

13 2 34 135 2 42 1 13 1 14 1 10 1

Group

BMWP family

Species

Common name

Trichoptera

Hydroptilidae

Hydroptila sp.

Cased caddis

Trichoptera

Hydroptilidae

Oxyethira sp.

Cased caddis

Trichoptera

Goeridae

Silo nigricornis

Cased caddis

Trichoptera

Sericostomatidae

Sericostoma personatum

Cased caddis

Diptera

Ceratopogonidae

Biting midge

larvae

Diptera

Chironomidae

Non-biting midge

larvae

Diptera

Ephydridae

Shore fly

pupa

Diptera

Empididae

Dance fly

larvae

Diptera

Muscidae

Stable fly

larvae

Diptera

Psychodidae

Moth fly

Diptera

Simulidae

Simulium sp.

Blackflies

larvae early instars not identifiable to species

Diptera

Tipulidae(Pediciidae)

Dicranota sp.

cranefly

larvae

Others

Hydracarina

Water mite

Others

Oligochaeta

True worms

Limnophora riparia

Notes larvae not identifiable to species larvae not identifiable to species

# taxa Score ASPT

15

Abundance

BMWP

WHPT

58 4 1 6 56 5 5 58 7

6 10 10 2

6.5 8.8 8.9 5.4 1.3 4.4 7.0 2.6 4.5

15 1 3 47

5 5

6.1 5.4

1

2.3

54 2488

32 169 5.28

38.0 201.9 5.31

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Group

BMWP family

Species

Common name

Tricladida

Dendrocoelidae

Dendrocoelum lacteum

Flatworm

Tricladida

Planariidae

Polycelis felina

Flatworm

Tricladida

Planariidae

Polycelis tenuis

Flatworm

Mollusca

Lymnaeidae

Radix balthica

Wandering snail

Mollusca

Planorbidae

Anisus vortex

Whirlpool ramshorn

Mollusca

Valvatidae

Valvata cristata

Flat 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

Glossiphonidae

Glossiphonia complanata

Leech

Hirudinea

Glossiphonidae

Helobdella stagnalis

Leech

Ephemeroptera

Ephemerellidae

Serratella ignita

Blue-winged Olive

Ephemeroptera

Baetidae

Baetis rhodani

Large Dark Olive

Ephemeroptera

Baetidae

Baetis vernus

Medium Olive

Ephemeroptera

Ephemeridae

Ephemera danica

Greendrake

Megaloptera

Sialidae

Sialis lutaria

Alderfly

Hemiptera

Veliidae

Velia caprai

Water cricket

Coleoptera

Haliplidae

Brychius elevatus

Crawling water beetle

Coleoptera

Haliplidae

Haliplus lineatocollis

Crawling water beetle

Status

Abundance

BMWP

WHPT

Below Drayton

16

=Lymnaea peregra

4 2 4 4 7 1 48 1 24 364 4 33 2 4 9 2 2 1 3 3 5

5

3.0

5 3 3 3 6 3 3 6 3 3

4.7 3.6 3.2 3.3 5.5 4.4 2.3 4.6 3.6 2.5

10

7.9

4 10 4

5.9 8.3 4.2 4.5

Group

BMWP family

Species

Common name

Coleoptera

Haliplidae

Haliplus sibiricus

Crawling water beetle

Status

Haliplidae

Haliplus sp.

Crawling water beetle

Coleoptera

Dytiscidae

Oreodytes sanmarkii

Diving beetle

Coleoptera

Elmidae

Elmis aenea

Riffle beetle

larva and adults

Coleoptera

Elmidae

Limnius volckmari

Riffle beetle

larva and adults

Trichoptera

Hydropsychidae

Hydropsyche siltalai

Caseless caddis

Trichoptera

Rhyacophilidae

Rhyacophila dorsalis

Caseless caddis

Trichoptera

Glossosomatidae

Agapetus fuscipes

Saddle-case caddis

Trichoptera

Leptoceridae

Adicella reducta

Long-horned caddis

Trichoptera

Beraeidae

Beraeodes minutus

Cased caddis

Trichoptera

Limnephilidae

Limnephilus lunatus

Cased caddis

Trichoptera

Limnephilidae

Melampophylax mucoreus

Cased caddis

Trichoptera

Limnephilidae

Potamophylax latipennis

Cased caddis

Trichoptera

Goeridae

Silo nigricornis

Cased caddis

Trichoptera

Sericostomatidae

Sericostoma personatum

Cased caddis

Diptera

Ceratopogonidae

Biting midge

larvae

Diptera

Chironomidae

Non-biting midge

larvae

Diptera

Tipulidae(Pediciidae)

cranefly

larvae

Others

Hydracarina

Water mite

Others

Oligochaeta

True worms

# taxa Score ASPT

17

BMWP

1 larvae not identifiable to species

Coleoptera

Dicranota sp.

Abundance

1 17 177 1 1 1 6 1 16 1 1 3 5 1 5 15 2 13 123 41 918

5 5 5

3.4 4.8 8.3

5 7 7 10 10

5.8 8.1 7.8 6.7 7.3

7 10 10 2 5

5.9 8.8 8.9 5.4 1.3 5.4

1 29 160 5.52

1.4 31.0 160.8 5.19

Group

BMWP family

Species

Common name

Status

Tricladida

Planariidae

Polycelis tenuis

Flatworm

Mollusca

Physidae

Physa fontinalis

Bladder snail

Mollusca

Lymnaeidae

Stagnicola palustris

Marsh snail

=Lymnaea palustris

Mollusca

Lymnaeidae

Radix balthica

Wandering snail

=Lymnaea peregra

Mollusca

Planorbidae

Anisus vortex

Whirlpool ramshorn

Mollusca

Valvatidae

Valvata cristata

Flat valve snail

Mollusca

Valvatidae

Valvata piscinalis

Valve snail

Mollusca

Ancylidae

Ancylus fluviatilis

River limpet

Crustacea

Asellidae

Asellus aquaticus

Water slater

Crustacea

Gammaridae

Gammarus pulex

Freshwater shrimp

Hirudinea

Erpobdellidae

Erpobdella octoculata

Leech

Hirudinea

Glossiphonidae

Glossiphonia complanata

Leech

Hirudinea

Glossiphonidae

Helobdella stagnalis

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

Plecoptera

Nemouridae

Nemurella picteti

Stonefly

Plecoptera

Nemouridae

Nemoura cinerea

Stonefly

Coleoptera

Dytiscidae

Nebrioporus elegans

Diving beetle

Abundance

BMWP

WHPT

Above Drayton

18

4 5 1 124 17 4 6 10 6 159 26 8 47 1 14 51 63 1 1 11 2

5 3

4.7 2.7

3 3

1.2 3.0 3.1

6 3 6 3 3

5.5 4.0 4.5 2.0 2.5

4 10

5.2 8.5

4

7.2

7

10.7

Group

BMWP family

Species

Common name

Coleoptera

Dytiscidae

Oreodytes sanmarkii

Diving beetle

Coleoptera

Dytiscidae

Diving beetle

Coleoptera

Hydrophilidae

Anacaena limbata

Scavenger water beetle

Coleoptera

Elmidae

Elmis aenea

Riffle beetle

Trichoptera

Rhyacophilidae

Rhyacophila dorsalis

Caseless caddis

Trichoptera

Glossosomatidae

Agapetus fuscipes

Saddle-case caddis

Status larvae not identifiable to species larva and adults

larvae not identifiable to species larvae not identifiable to species

Trichoptera

Hydroptilidae

Hydroptila sp.

Cased caddis

Trichoptera

Hydroptilidae

Oxyethira sp.

Cased caddis

Trichoptera

Limnephilidae

Drusus annulatus

Cased caddis

Trichoptera

Limnephilidae

Limnephilus lunatus

Cased caddis

Trichoptera

Goeridae

Silo nigricornis

Cased caddis

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

Diptera

Simulidae

Simulium sp.

Blackflies

larvae early instars not identifiable to species

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Abundance

BMWP

WHPT

49

5

4.8

16 1 9 3 9

5 5 7 7

5.8 5.3 8.1 7.8

56

6

6.8

7

6.9

10 2

8.8 -0.9 2.0 7.0 7.6 4.4 4.0 3.3

5

6.1

76 36 1 1 153 1 3 65 3 7 53 83

Group

BMWP family

Diptera

Species

Common name

Status

Stratiomyidae

Soldier fly

larvae

Diptera

Tipulidae

cranefly

larvae

Diptera

Tipulidae(Pediciidae)

cranefly

larvae

Others

Hydracarina

Water mite

Others

Oligochaeta

True worms

Dicranota sp.

# taxa Score ASPT

20

Abundance

1 9 12 1 33 45 1242

BMWP

WHPT

5

3.6 6.9

1

2.3

25 125 5.00

33.0 165.4 5.01

Group

BMWP family

Species

Common name

Status

Tricladida

Dendrocoelidae

Dendrocoelum lacteum

Flatworm

Tricladida

Planariidae

Polycelis nigra

Flatworm

Mollusca

Physidae

Physa fontinalis

Bladder snail

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

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

Glossiphonidae

Glossiphonia complanata

Leech

Hirudinea

Glossiphonidae

Helobdella stagnalis

Leech

Hirudinea

Glossiphonidae

Theromyzon tessulatum

Duck leech

Plecoptera

Leuctridae

Leuctra fusca

Stonefly

Plecoptera

Nemouridae

Nemurella picteti

Stonefly

Abundance

BMWP

WHPT

Manor Farm

21

1 21 4 17 1 6 14 2 10 2 31 5 85 1341 27 9 1 5 3 19

5 5 3

3.0 5.4 2.7

3

2.5

3

3.0

3 6 3 3 6 3

3.1 5.5 4.4 2.3 3.9 2.0

3 10 7

2.5 9.3 10.7

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

Coleoptera

Haliplidae

Haliplus lineatocollis

Crawling water beetle

Status

Coleoptera

Haliplidae

Haliplus sp.

Crawling water beetle

larvae not identifiable to species

Coleoptera

Elmidae

Elmis aenea

Riffle beetle

larva and adults

Coleoptera

Elmidae

Limnius volckmari

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 sp.

Cased caddis

Trichoptera

Hydroptilidae

Hydroptila sp.

Cased caddis

Trichoptera

Hydroptilidae

Oxyethira sp.

Cased caddis

Trichoptera

Leptoceridae

Adicella reducta

Long-horned 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

22

larvae not identifiable to species larvae not identifiable to species

Abundance

BMWP

WHPT

31

10

8.5

333 179 2 1

4 7

7.2 6.5

5

3.4

5

7.4 6.9

5 7

5.8 8.1 7.6

6 10 7 10 10 10

6.8 6.7 5.9 8.8 11.1 8.9

13 55 1 7 2 2 5 24 1 61 90 5 2 7 1 1

Group

BMWP family

Diptera

Species

Common name

Status

Ceratopogonidae

Biting midge

larvae

Diptera

Chironomidae

Non-biting midge

larvae

Diptera

Dixidae

Meniscus midges

larvae

Diptera

Empididae

Dance fly

larvae

Diptera

Muscidae

Stable fly

pupa and larva

Diptera

Psychodidae

Limnophora riparia Pericoma sp. + Psychoda sp.

Moth fly

Diptera

Simulidae

Simulium ornatum gr.

Blackflies

larvae early instars not identifiable to species

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

# taxa Score ASPT

23

Abundance

11 63 23 2 12

BMWP

WHPT

2

28

5.5 1.3 7.0 7.0 2.6 3.0

81 2 7 1 10 32

5

6.1

5

6.9

1

2.3

53 2699

31 172 5.55

38.0 211.6 5.57