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 :ď‚· ď‚· ď‚· ď‚·
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 :ď‚· ď‚· ď‚·
ď‚·
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