Macroinvertebrate Survey of watercress farm outflows, Alresford , Hants 2020

Macroinvertebrate Survey of watercress farm outflows, Alresford , Hants 2020

Report prepared by Robert Aquilina MSc MCIEEM

May 2020

Macroinvertebrate survey of watercress farm outflows, Alresford, Hants 2020

Robert Aquilina MSc MCIEEM

May 2020

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 .......................................................................................................... 14 References ........................................................................................................... 15 Appendix 1 Species recorded. ............................................................................... 16

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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 high water quality scores. A complete list of species is presented together with abundance and diversity (WHPT) scores. Increases in all the indices indicating improved biodiversity are discussed in terms of water quality, variation in sampling efficacy and natural environmental variation due to weather.

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Introduction

The purpose of this survey was to repeat the annual assessments 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 similar to those used previously and as such, this report follows the format of the previous reports (Aquilina, 2018 and 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.

Sample points at all sites were the same as for previous sampling and correspond in some cases to Environment Agency sampling sites.

The Drayton sites were visited by Robert Aquilina on Wednesday 6th May 2020 and Manor Farm and Bishops Sutton on Thursday 14th May 2020, both dates slightly earlier in May than on previous years. The reason for the split visits was that the weather was unusually warm and no refrigeration was available to store samples whilst waiting to be sorted as in previous years. Therefore there was concern that samples may deteriorate affecting the results. By splitting the sampling, sorting could take place on the same and following day as collection. See further discussion below.

Samples were collected for analysis in the laboratory using standard techniques. The weather conditions were warm, dry and sunny and suitable for the survey with normal water flow levels on both occasions.

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 (TL5) 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 5

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 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 live sorted and specimens preserved in 70% IMS for identification.

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.

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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 2019 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 little Ranunculus growth (unlike previous years) 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 gravel.

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Photograph 1: Bishop’s Sutton outflow 2020

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 2020

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.

Ranunculus growth had reduced to levels found in 2018 and occupied approximately half the channel with the remainder being exposed gravel. Therefore sampling was equally concentrated in the Ranunculus and the gravel, with some marginal vegetation being sampled.

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Photograph 3: above Drayton outflow 2020

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 fallen tree has been removed which has improved water flow but almost all in-channel vegetation has been removed. Therefore sampling was almost exclusively in the gravel with a little marginal Veronica (Water speedwell) being sampled.

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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 current and previous years. 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

Bishop’s Sutton

# species Abundance N-taxa WHPT ASPT

22.5.2018 28.5.2019 14.5.2020 Below Drayton Farm 22.5.2018 28.5.2019 6.5.2020 Above Drayton Farm 22.5.2018 28.5.2019 6.5.2020 Manor Farm 22.5.2018 28.5.2019 14.5.2020

49 31 51 47 40 52 46 39 47 53 39 47

1237 1478 1660 813 1165 1331 1966 1809 1835 1675 2515 2032

35 27 36 34 31 38 32 29 37 38 34 38

194.6 139.3 196.5 174.8 154.3 204.4 149.4 146.9 197.2 204.8 186.5 215.2

5.56 5.16 5.46 5.14 4.98 5.38 4.67 5.07 5.33 5.39 5.49 5.66

Table 2. Results summary

Site

BMWP

Bishop’s Sutton Below Drayton Above Drayton Manor Farm

170 174 165 184

WHPT N-taxa (BMWP) 196.5 32 204.4 32 197.2 31 215.2 31

N-taxa (WHPT) 36 38 37 38

ASPT (BMWP) 5.31 5.44 5.32 5.94

ASPT (WHPT) 5.46 5.38 5.33 5.66

Table 3. BMWP v WHPT results comparison 2020 The results show a consistent increase in scores for every index for each site with one minor exception (abundance at Manor Farm) but abundance is the most variable of all the measures and variation (sometimes large) between years would not be unexpected.

Improvements in scores are highlighted in blue in Tables 2 and 4.

Table 3 shows a consistently greater score on the WHPT index than on the old BMWP index.

Most of the indices are comparable or greater than those from 2018.

Gammarus counts are summarised below but also show an increase at all sites.

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Site

2018 2019 2020

Bishop’s Sutton Below Drayton Above Drayton Manor Farm

323 91 223 638

405 243 115 272

530 386 261 805

Table 5. Gammarus counts

The improvements in all the indices across all the sites suggest that recovery from the depressed levels in 2019 has occurred. Reasons for this are explored below. The results are consistent with good water quality and high biodiversity, as would be expected in chalk streams showing little impact from the watercress operations.

Increases in biodiversity which are reflected in these indices are due to a number of factors :   

Water quality improvements Weather Stream management Sampling

Clearly the water is of sufficient quality to allow the most sensitive of the invertebrate families to exist. Although many of the highest scoring families are present as singletons or very few in number, this is what would be expected from recolonization which is not necessarily a rapid process.

The weather has remained remarkably mild through the winter and spring and may well have contributed to the higher scores, especially likely to be responsible for the abundance element, both overall and for Gammarus counts. Some individual species counts are down on previous years but these are mostly minor. The most significant is that for mayflies, especially Baetid mayflies which are most dramatically affected by the presence of vegetation. All sites appeared to have reduced in-channel growth of Ranunculus which is the preferred habitat for these mayflies and therefore lower counts might be anticipated.

The only other factor which has changed is the split in sampling sites across two dates, which was because of concerns that samples sorted later in the process would have deteriorated due to the warmth. Live sorting is more efficient than sorting a preserved sample as the movement tends to advertise the presence of invertebrates which might otherwise require more concentrated effort to recover. However, this is likely to affect only one of the sites (the last to be sorted) and minimally at that.

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It is interesting that all the sites have seen an increase in the presence of the highest scoring (i.e. most sensitive) families albeit as single or a couple of individual animals.

The presence of Heptageneid mayflies and Perlodid stoneflies is welcome news.

Conclusions Three years of sampling data is now available. The results indicate a return to and improvement upon 2018 scores which were better than 2019. There has been a consistent improvement in Gammarus counts across the three years for two sites.

Factors which will affect the results year on year are :  



Normal variation in sampling efficiency which includes live sorting versus sorting a preserved sample.

Natural year on year variation in abundance and species presence. In particular, the weather conditions.

Stream management – in particular, clearance of in-channel vegetation which is carried out to improve water flow but can affect biodiversity. Both positive and negative effects can be seen in that removal of Ranunculus reduces habitat for e.g. Baetid mayflies but increases unsilted gravel area for Heptageneid mayflies.

Recolonisation events as species move in to take advantage of clean new habitats

Clearly water quality is good enough to maintain high biodiversity, other factors being equal. Of course overlaid on this is the year on year natural variation that weather and management bring.

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

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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.

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

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

Notes

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

=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

Erpobdellidae

Trocheta subviridis

Leech

Hirudinea

Glossiphonidae

Glossiphonia complanata

Leech

Abundance

BMWP

WHPT

5 1 5 19

5

3.0 2.8

5

5.4

5

3

3.6

13

3

3.0

11 5 13 2 68 805 67

3 6 3 3 6 3

3.1 5.5 4.4 2.3 4.6 2.0

3

3

2.5

Bishops Sutton

Group

BMWP family

Species

Common name

Hirudinea

Glossiphonidae

Helobdella stagnalis

Leech

Hirudinea

Glossiphonidae

Theromyzon tessulatum

Hirudinea

Piscicolidae

Piscicola geometra

Fish leech

Plecoptera

Leuctridae

Leuctra fusca

Stonefly

Plecoptera

Nemouridae

Nemurella picteti

Stonefly

Plecoptera

Perlodidae

Isoperla grammatica

Stonefly

Ephemeroptera

Ephemerellidae

Serratella ignita

Ephemeroptera

Baetidae

Ephemeroptera

Notes

Abundance

BMWP

WHPT

1 1

7 10

Blue-winged Olive

132

10

8.7 10.5 9.0

Baetis rhodani

Large Dark Olive

Baetidae

Baetis vernus

Medium Olive

75 76

4

7.2

Ephemeroptera

Caenidae

Caenis luctuosa

Mayfly

Ephemeroptera

Caenidae

Caenis rivulorum

Mayfly

Ephemeroptera

Ephemeridae

Ephemera danica

Greendrake

Ephemeroptera

Heptageniidae

Rithrogena semicolorata

Olive upright

98 2 2

7 10 10

6.5 8.3 8.5

Hemiptera

Gerridae

Gerris sp.

Water skater

nymph

Hemiptera

Veliidae

Velia caprai

Water cricket

nymph

Coleoptera

Haliplidae

Haliplus lineatocollis

Crawling water beetle

Coleoptera

Haliplidae

Haliplus sp.

Crawling water beetle

Coleoptera

Dytiscidae

Oreodytes sanmarkii

Coleoptera

Hydrophilidae

Helophorus sp.

Diving beetle Scavenger water beetle

Coleoptera

Elmidae

Elmis aenea

Riffle beetle

larva and adults

5

7.4

Coleoptera

Elmidae

Limnius volckmari

Riffle beetle

larvae

Coleoptera

Elmidae

Riolus subviolaceus

Riffle beetle

larva and adults

10

17

larvae not identifiable to species

females not identifiable to species

50 4 2

Group

BMWP family

Species

Common name

Notes

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 larvae not identifiable to species

Abundance

BMWP

WHPT

136 9 7

5 7

7.4 8.1 7.8

10

6

6.5

10 7

6.7 5.9

Trichoptera

Hydroptilidae

Hydroptila sp.

Cased caddis

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

Drusus annulatus

Cased caddis

Trichoptera

Limnephilidae

Limnephilus lunatus

Cased caddis

Trichoptera

Limnephilidae

Potamophylax cingulatus

Cased caddis

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

Diptera

Ephydridae

Shore fly

pupa and larva

Diptera

Muscidae

Stable fly

pupa and larva

Cased caddis

Limnophora riparia

18

2 2 1 1

early instars not identifiable to species

2 6 19 17 33

3

10 10 10 2

8.8 11.1 9.4 5.5 1.3

4.0

Group

BMWP family

Species

Common name

Notes

Abundance

Diptera

Psychodidae

Pericoma sp. + Psychoda sp.

Moth fly

larvae

Diptera

Sciomyzidae

Snail-killing flies

Diptera

Simulidae

Blackflies

larvae early instars not identifiable to species

2 2

Diptera

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

Simulium ornatum gr.

Total ASPT

19

WHPT

4.5 3.4

99 1

5

6.1 3.6

3

5

5.4

24 178

1

1.4

31 184 5.94

38.0 215.2 5.66

47 2032

N-taxa

BMWP

Group

BMWP family

Species

Common name

Notes

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

Stagnicola palustris

Marsh snail

=Lymnaea palustris

Mollusca

Lymnaeidae

Radix balthica

Wandering snail

=Lymnaea peregra

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

Abundance

BMWP

WHPT

18 2 6 73

5 3

5.4 2.7

3

2.5

18

3

3.0

2 9 2 1 32

3

3.1

6 3 3

5.8 4.4 2.3

261 135

6 3

4.5 -0.8

Above Drayton

Twisted ramshorn

20

Group

BMWP family

Species

Common name

Notes

Hirudinea

Erpobdellidae

Leech

Hirudinea

Glossiphonidae

Trocheta subviridis Glossiphonia complanata

Hirudinea

Glossiphonidae

Helobdella stagnalis

Leech

Hirudinea

Glossiphonidae

Theromyzon tessulatum

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

Plecoptera

Perlodidae

Isoperla grammatica

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 local

Coleoptera

Haliplidae

Haliplus sp.

Crawling water beetle

Leech

21

Abundance

BMWP

WHPT

25 246

3

0.8

4 67 207 78

4 10

5.2 8.5

4

7.2

3 2 2 5 1

7 10 7

6.5 8.3 8.7

10

10.5

nymph

1

larvae not identifiable to species

4.5

Group

BMWP family

Species

Common name

Coleoptera

Dytiscidae

Nebrioporus elegans

Diving beetle

Coleoptera

Dytiscidae

Oreodytes sanmarkii

Diving beetle Diving beetle

Notes

WHPT

22

5

4.8

5

5.3

1 2 1 2

5 7

6.9 5.8 8.2

1 5

7 7

8.1 7.8

30

6

6.5

7

6.9

1

5

Dytiscidae

Coleoptera

Hydrophilidae

Anacaena limbata

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

Polycentropodidae

Plectrocnemia conspersa

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

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

22

BMWP

larvae not identifiable to species

Coleoptera

Cased caddis

Abundance

larvae not identifiable to species larvae not identifiable to species

8

63 17

Group

BMWP family

Species

Common name

Trichoptera

Limnephilidae

Micropterna lateralis

Cased caddis

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

Meniscus midge

larvae

Diptera

Empididae

Dance fly

pupa

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

Tipulidae

cranefly

larvae

Diptera

Tipulidae (Limoniidae)

cranefly

larvae

Diptera

Tipulidae(Pediciidae)

cranefly

larvae

Others

Hydracarina

Water mite

Others

Oligochaeta

True worms

Cased caddis

Notes

Abundance

BMWP

WHPT

9

10

8.9

2

5.5 1.3

early instars not identifiable to species

larvae

Dixa nebulosa

Simulium sp.

Dicranota sp.

23

50 75

1

7.0

1

4.0

221 3

5

5.8 3.6

2 36 79

5

5.4

1

2.3

Group

BMWP family

Species

Common name

N-taxa Total ASPT

24

Notes

Abundance

BMWP

WHPT

47 1835

31 165 5.32

37.0 197.2 5.33

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

Galba truncatula

Dwarf pond 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

Trocheta subviridis

Leech

Notes

Abundance

BMWP

WHPT

1

5

3.0

5

5

4.7

4 1 1

3 3

2.7 3.6

12

3

3.0

6

3

3.3

7 9 32

6 3 3

5.8 4.4 2.3

386 8

6 3

4.6 3.6

Below Drayton

=Lymnaea peregra

Twisted ramshorn

25

Group

BMWP family

Species

Common name

Hirudinea

Glossiphonidae

Glossiphonia complanata

Leech

Hirudinea

Glossiphonidae

Helobdella stagnalis

Leech

Hirudinea

Glossiphonidae

Theromyzon tessulatum

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

Caenidae

Caenis rivulorum

Mayfly

Ephemeroptera

Ephemeridae

Ephemera danica

Greendrake

Ephemeroptera

Heptagenidae

Heptagenia sulphurea

Megaloptera

Sialidae

Sialis lutaria

Plecoptera

Leuctridae

Leuctra nigra

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

Coleoptera

Hydrophilidae

Anacaena globulus

Scavenger water beetle

Coleoptera

Hydrophilidae

Helophorus brevipalpis

Scavenger water beetle

Coleoptera

Elmidae

Elmis aenea

Riffle beetle

Notes

Alderfly

BMWP

WHPT

38

3

2.5

162 20 28 30 2 1 4 1

10 4

9.0 5.9

7 10 10 4 10

6.5 8.3 8.5 4.2 9.3

1 1

5

4.5 3.6

8

5

4.5

227

5

8.3

nymph

larvae not identifiable to species

larva and adults

26

Abundance

Abundance

BMWP

WHPT

13

5

7.2

2 2

7

8.1 7.8

10

6

6.5

4 1

10

6.7

7

6.9

Group

BMWP family

Species

Common name

Notes

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

Trichoptera

Hydroptilidae

Oxyethira sp.

Cased caddis

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

Cased caddis

Trichoptera

Limnephilidae

Limnephilus rhombicus Melampophylax mucoreus

2 5 3 13 1

Cased caddis

16

Trichoptera

Limnephilidae

Cased caddis

Trichoptera

Limnephilidae

Micropterna lateralis Potamophylax cingulatus

Trichoptera

Limnephilidae

Potamophylax latipennis

Cased caddis

Trichoptera

Limnephilidae

larvae not identifiable to species larvae not identifiable to species

2 24

Cased caddis

Cased caddis

27

2 1

early instars not identifiable to species

1

Group

BMWP family

Species

Common name

Notes

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

Empididae

Diptera

Ephydridae

Diptera

Psychodidae

Diptera

Scathophagidae

Diptera

Sciomyzidae

Diptera

Simulidae

Diptera

Abundance

BMWP

WHPT

17

10

9.4

15 28

2

5.5 1.3

larvae

Dixa nebulosa

larvae Pericoma sp.

Shore flies

pupae

Moth fly

larvae

3

7.0

1

4.5

larvae Snail-killing flies Blackflies

larvae early instars not identifiable to species

Stratiomyidae

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

Simulium sp.

Dicranota sp.

N-taxa Total ASPT

28

17 1

5

6.1 3.6

1 106 45

5

5.4

1

2.3

52 1331

32 174 5.44

38.0 204.4 5.38

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

Flatworm

Tricladida

Planariidae

Polycelis tenuis

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

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

Trocheta subviridis

Leech

Hirudinea

Glossiphonidae

Glossiphonia complanata

Leech

Hirudinea

Glossiphonidae

Helobdella stagnalis

Leech

Abundance

BMWP

WHPT

5 1 5 19

5

3.0 2.8

5

5.4

5

3

3.6

13

3

3.0

11 5 13 2 68 805 67

3 6 3 3 6 3

3.1 5.5 4.4 2.3 4.6 2.0

3

2.5

Manor Farm

Twisted ramshorn

3 10

29

Group

BMWP family

Species

Common name

Hirudinea

Glossiphonidae

Theromyzon tessulatum

Hirudinea

Piscicolidae

Piscicola geometra

Fish leech

Plecoptera

Leuctridae

Leuctra fusca

Stonefly

Plecoptera

Nemouridae

Nemurella picteti

Stonefly

Plecoptera

Perlodidae

Isoperla grammatica

Stonefly

Ephemeroptera

Ephemerellidae

Serratella ignita

Ephemeroptera

Baetidae

Ephemeroptera

Abundance

BMWP

WHPT

1 1

7 10

Blue-winged Olive

132

10

8.7 10.5 9.0

Baetis rhodani

Large Dark Olive

Baetidae

Baetis vernus

Medium Olive

75 76

4

7.2

Ephemeroptera

Caenidae

Caenis luctuosa

Mayfly

Ephemeroptera

Caenidae

Caenis rivulorum

Mayfly

Ephemeroptera

Ephemeridae

Ephemera danica

Greendrake

Ephemeroptera

Heptageniidae

Rithrogena semicolorata

Olive upright

98 2 2

7 10 10

6.5 8.3 8.5

Hemiptera

Gerridae

Gerris sp.

Water skater

nymph

Hemiptera

Veliidae

Velia caprai

Water cricket

nymph

Coleoptera

Haliplidae

Haliplus lineatocollis

Crawling water beetle

Coleoptera

Haliplidae

Haliplus sp.

Crawling water beetle

Coleoptera

Dytiscidae

Oreodytes sanmarkii

Coleoptera

Hydrophilidae

Helophorus sp.

Diving beetle Scavenger water beetle

Coleoptera

Elmidae

Elmis aenea

Riffle beetle

larva and adults

5

7.4

Coleoptera

Elmidae

Limnius volckmari

Riffle beetle

larvae

Coleoptera

Elmidae

Riolus subviolaceus

Riffle beetle

larva and adults

Coleoptera

Scirtidae

Elodes sp.

Marsh beetle

larva

30

Status

larvae not identifiable to species

females not identifiable to species

50 4 2

Group

BMWP family

Species

Common name

Status

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

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

Drusus annulatus

Cased caddis

Trichoptera

Limnephilidae

Limnephilus lunatus

Cased caddis

Trichoptera

Limnephilidae

Potamophylax cingulatus

Cased caddis

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

Diptera

Ephydridae

Shore fly

pupa and larva

Diptera

Muscidae

Limnophora riparia

Stable fly

pupa and larva

Diptera

Psychodidae

Pericoma+Psychoda sp.

Moth fly

larvae

larvae not identifiable to species

BMWP

WHPT

136 9 7

5 7

7.4 8.1 7.8

10

6

6.5

10 7

6.7 5.9

10 10 10

8.8 11.1 9.4 5.5 1.3

2 2 1 1

Cased caddis

31

Abundance

early instars not identifiable to species

2 6 19 17 33

3 2

2

4.0 4.5

Group

BMWP family

Diptera

Sciomyzidae

Diptera

Simulidae

Diptera

Species

Common name

Status

Snail-killing flies Blackflies

larvae early instars not identifiable to species

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

Simulium ornatum gr.

Abundance

2

Total ASPT

32

WHPT

3.4

99 1

5

6.1 3.6

3

5

5.4

24 178

1

1.4

31 184 5.94

38.0 215.2 5.66

47 2032

N-taxa

BMWP