Macroinvertebrate Survey of three watercress farm outflows, Alresford , Hants
Report prepared by Robert Aquilina MSc MCIEEM
June 2018
Macroinvertebrate survey of three watercress farm outflows, Alresford, Hants
Robert Aquilina MSc MCIEEM
June 2018
Robert Aquilina MSc MCIEEM is an independent consulting ecologist specialising in protected species and freshwater ecology. He is a Full member of the Institute of Ecology and Environmental Management and abides by their Code of Professional Conduct. For further details see www.cieem.net www.aquilina-environmental.co.uk
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Table of contents Summary ................................................................................................................ 4 Introduction ........................................................................................................... 5 Methods................................................................................................................. 5 BMWP ......................................................................................................................................... 6 WHPT .......................................................................................................................................... 6 Locations ..................................................................................................................................... 7
Results ................................................................................................................... 9 Conclusions ...........................................................................................................11 References ............................................................................................................11 Appendix 1 Species recorded. ................................................................................12
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Summary
Macroinvertebrate surveys of outflows from Bishop’s Sutton, Drayton and Manor Farm watercress farms at Alresford, Hampshire were carried out using standard sampling techniques. The purpose was to establish a baseline for future monitoring based on standard methodologies in order to 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 and BMWP) scores.
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Introduction
The purpose of this survey was to assess the discharge from the watercress beds at Bishop’s Sutton, Drayton and Manor Farm around Alresford and identify any impacts that they may be having downstream. 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. The site was visited by Robert Aquilina on Tuesday 22nd May 2018 and samples were collected for analysis in the laboratory using standard techniques. The weather conditions were dry and suitable for the survey with normal water flow levels. Industry standard survey and extraction techniques for the stream (Environment Agency 2012) were used to assess the species present. Methods The methodology followed is the standard Environment Agency survey and extraction protocol which results in a species list with abundance data. This forms the basis for calculating a number of indices designed to assess the impacts of various factors (depending on the index selected) but in this case is used to calculate the standard BMWP and its more sophisticated modification WHPT. Aquatic macroinvertebrates were collected using a standard size FBA D-frame pond net from the major habitats along the stream (stands of different wetland plants, distinctive substrates, tree roots etc.). All the different habitats present were allocated a proportion of the overall sampling time (3 minutes) and different areas of 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 5
recorded : Tricladida (flatworms), Gastropoda (snails and bivalves), Crustacea (slaters, shrimps and crayfish), Hirudinea (leeches), Megaloptera (alderflies), Plecoptera (stoneflies), Ephemeroptera (mayflies), Odonata (dragonflies and damselflies), Hemiptera (water bugs), Coleoptera (water beetles), Trichoptera (caddisflies) and Diptera (true flies). Voucher specimens were retained in order to check their identity. Dead mollusc shells, and empty caddis cases were discarded and only whole animals were included in the counts.
BMWP Condition assessment of running waters is based on the BMWP (Biological Monitoring Working Party) score. These BMWP family scores (1-10) are industry standard and reflect the sensitivity of the families to pollution. The higher the family score, the more sensitive to oxygen depletion the family is and therefore their presence indicates a cleaner or less impacted site. The effects of pollution generally are to impose a Biological Oxygen Demand upon the receiving waters and so sensitive families are progressively excluded as the BOD increases. The score for each family present is totalled to give a site score. Because these site BMWP scores are influenced by sample size (a high score can be achieved through a large number of low scoring families as well as a small number of high scoring families) an Average Score Per Taxa (ASPT) is also calculated from the resulting BMWP scores and allows further interpretation of the results. The higher the ASPT, the greater the proportion of more sensitive families in the sample and therefore the better the site condition.
WHPT WHPT better reflects the quality of the invertebrate community because it is based on a wider range of taxa (mostly families), in particular, WHPT includes more families of Diptera and some families that were grouped together in BMWP (known as BMWP composite taxa) are considered separately in WHPT. So 106 taxa are included in WHPT as opposed to the 82 in BMWP. Additionally the abundance of each taxa is taken into account through the use of abundance classes, the WHPT score for each taxa present depending on its abundance.
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Abundance category Numerical abundance AB1 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
The Bishop’s Sutton outflow is located at SU 60400 32321.
Photograph 1: Bishop’s Sutton outflow 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
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vegetation and the Fontinalis moss growing downstream of the weir. Sampling was concentrated in the Ranunculus and gravel. The Drayton outflow was located at SU 59358 33272.
Photograph 2: Drayton outflow The sample reach was downstream of a bridge with culverts discharging the water, leading to scour in the channel bed. Despite this, 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.
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The Manor Farm outflow is located at SU 58532 33516.
Photograph 3: Manor Farm outflow. The habitats present consisted of cobbles, small stone, gravel, coarse sand, Ranunculus beds and marginal watercress. Each was sampled for thirty seconds. There was noticeably less in-channel and marginal vegetation than on the previous visit (November 2016).
Results
The full species lists and abundance are presented as an appendix. The results summarised here consist of BMWP, N-taxa and ASPT as well as WHPT, N-taxa and ASPT. These are presented by site as well as by index for comparative purposes. A previous visit to Manor Farm had taken place in November 2016 when a standard sample had been collected and BMWP scores calculated. These are included in the results here for comparison but note that it represents a completely different season 9
(autumn as opposed to spring). It was possible to calculate the WHPT scores associated with this previous visit because the full inventory of species was recorded with abundance and included the full suite of Dipteran families.
Index
Manor Farm Drayton Bishop’s Sutton Nov 2016 May 2018
# contributing taxa BMWP ASPT Total # taxa
30 163 5.43
29 160 5.52
31 164 5.29
29 159 5.48
51
53
47
49
Table 2. BMWP results summary
Index
Manor Farm Drayton Bishop’s Sutton Nov 2016 May 2018
# contributing taxa WHPT ASPT
36.0 188.7 5.24
38.0 204.8 5.39
34.0 174.8 5.14
35.0 194.6 5.56
Table 3. WHPT results summary
Site Manor Farm (Nov 2016) Manor Farm (May 2018) Drayton Bishop’s Sutton
BMWP WHPT N-taxa (BMWP) 163 188.7 30
N-taxa (WHPT) 36
ASPT (BMWP) 5.43
ASPT (WHPT) 5.24
160
204.8
29
38
5.52
5.39
164 159
174.8 194.6
31 29
34 35
5.29 5.48
5.14 5.56
Table 4. BMWP v WHPT results comparison
The results show an increase of WHPT score over BMWP as expected due to the increased number of contributing taxa (N-taxa). Except for Bishop’s Sutton, WHPT ASPT scores are lower, again as expected due to the increased N-taxa.
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Conclusions The results provide a baseline for future monitoring (scheduled for September 2018). Interpretation would be expected to follow from a RICT (River Invertebrate Classification Tool) analysis in order to provide EQI’s from reference condition that can be related to Water Framework Directive bands. However, this is not the point of this exercise. It is clear that WHPT will provide a more accurate indication of water quality and that regular sampling will provide a check on the effects of watercress management activities upon the streams, but also on the seasonal changes to be expected. WHPT scores are comparable between sites and also between season for Manor Farm.
References Aquilina, R. (2016). Macroinvertebrate Survey of Manor Farm outflow, Old Alresford, Hants. 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. RMA Environmental. (2012). Invertebrate Monitoring Spring 2012, The River Alre Catchment and Alresford Pond New Alresford, Hampshire.
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Appendix 1 Species recorded. 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
Lymnaea palustris
Marsh Pond snail
Mollusca
Lymnaeidae
Radix balthica
Wandering snail
Mollusca
Planorbidae
Anisus leucostoma
Mollusca
Planorbidae
Anisus vortex
Button ramshorn Whirlpool ramshorn
Mollusca
Planorbidae
Bathyomphalus contortus
Twisted ramshorn
Mollusca
Valvatidae
Valvata cristata
Mollusca
Valvatidae
Valvata piscinalis
Flat valve snail Common 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
Erpobdellidae
Trocheta subviridis
Leech
Notes
Abundance
BMWP
WHPT
Bishops Sutton 1 2 13 20 17
5 5
3.0 2.8
5.4
1 17
3
2.5
1
3
3.3
6
5.8 2.3 4.6 2.0
1 8 84 323 30
3 6 3
Group
BMWP family
Species
Common name
Hirudinea
Glossiphonidae
Glossiphonia complanata
Leech
Hirudinea
Glossiphonidae
Helobdella stagnalis
Leech
Hirudinea
Glossiphonidae
Theromyzon tessulatum
Duck leech
Hirudinea
Piscicolidae
Piscicola geometra
Fish leech
Plecoptera
Nemouridae
Nemurella picteti
Stonefly
Ephemeroptera
Ephemerellidae
Serratella ignita
Blue-winged Olive
Ephemeroptera
Baetidae
Baetis rhodani
Large Dark Olive
Ephemeroptera
Baetidae
Baetis vernus
Medium Olive
Ephemeroptera
Caenidae
Caenis sp.
Mayfly
Hemiptera
Gerridae
Gerris sp.
Water skater
Hemiptera
Veliidae
Velia caprai
Coleoptera
Haliplidae
Brychius elevatus
Water cricket Crawling water beetle
Coleoptera
Haliplidae
Haliplus lineatocollis
Crawling water beetle
Coleoptera
Haliplidae
Haliplus sp.
Crawling water beetle
Coleoptera
Dytiscidae
Oreodytes sanmarkii
Diving beetle
Coleoptera
Elmidae
Elmis aenea
Riffle beetle
Coleoptera
Elmidae
Riolus subviolaceus
Riffle beetle
Coleoptera
Scirtidae
Microcara testacea
Marsh beetle
Trichoptera
Hydropsychidae
Caseless caddis
Trichoptera
Polycentropodidae
Hydropsyche siltalai Polycentropus flavomaculatus
Trichoptera
Rhyacophilidae
Rhyacophila dorsalis
Caseless caddis
Trichoptera
Glossosomatidae
Agapetus fuscipes
Saddle-case caddis
Trichoptera
Hydroptilidae
Hydroptila sp.
Cased caddis
Caseless caddis
13
Notes
local
local
Abundance
BMWP
WHPT
7 2
3
3.4
2 1 162 36 106
4 7
5.2 8.7
10
9.0
4
7.2
1 1
5
5.2 4.5
7 1 6 5 39 4 2 12
5
3.4
5
4.5
5
7.4
5
7.2
1 14 21 58
7
8.2
7
9.2
7
7.6
6
6.5
6.9
Group
BMWP family
Species
Common name
Trichoptera
Hydroptilidae
Oxyethira sp.
Cased caddis
Trichoptera
Leptoceridae
Mystacides sp.
Long-horned caddis
Trichoptera
Limnephilidae
Drusus annulatus
Cased caddis
Trichoptera
Limnephilidae
Limnephilus lunatus
Cased caddis
Trichoptera
Limnephilidae
Potamophylax latipennis
Cased caddis
Trichoptera
Goeridae
Silo nigricornis
Cased caddis
Trichoptera
Odontoceridae
Odontocerum albicorne
Silver sedge
Trichoptera
Sericostomatidae
Sericostoma personatum
Cased caddis
Diptera
Ceratopogonidae
Biting midge
Diptera
Chironomidae
Non-biting midge
Diptera
Ephydridae
Shore fly
Diptera
Psychodidae
Moth fly
Diptera
Sciomyzidae
Snail-killing flies
Diptera
Simulidae
Diptera
Stratiomyidae
Soldier fly
Diptera
Tipulidae
cranefly
Diptera
Tipulidae(Pediciidae)
cranefly
Others
Hydracarina
Water mite
Others
Oligochaeta
True worms
Simulium sp.
Notes
Abundance
WHPT
2 2 7 2 3 2 14 15 97 1
2 1
Blackflies
38 45 # taxa score ASPT
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BMWP
49 1237
7
6.9
10
8.8
10
11.1
10
9.4 5.5
2
1.3
4.4
5
5.5 3.6
1
2.3
29 159 5.48
35.0 194.6 5.56
Group
BMWP family
Species
Common name
Tricladida
Dendrocoelidae
Dendrocoelum lacteum
Flatworm
Tricladida
Dugesiidae
Dugesia polychroa gr.
Flatworm
Tricladida
Planariidae
Polycelis felina
Flatworm
Tricladida
Planariidae
Polycelis nigra
Flatworm
Tricladida
Planariidae
Polycelis tenuis
Flatworm
Mollusca
Physidae
Physa fontinalis
Bladder snail
Mollusca
Lymnaeidae
Radix balthica
Mollusca
Planorbidae
Anisus leucostoma
Mollusca
Planorbidae
Mollusca
Planorbidae
Anisus vortex Bathyomphalus contortus
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
Erpobdellidae
Leech
Hirudinea
Glossiphonidae
Trocheta subviridis Glossiphonia complanata
Hirudinea
Glossiphonidae
Helobdella stagnalis
Leech
Notes
Abundance
BMWP
WHPT
Drayton
1
5
4.7
Wandering snail
33
3
2.5
Button ramshorn Whirlpool ramshorn
25
3
3.0
3 4 88 12 91 3
3
3.3
6
5.8
6
Twisted ramshorn
Leech
15
3
3.5
3 3
2.3 4.5 3.6
3
3.4
6
Group
BMWP family
Species
Common name
Hirudinea
Glossiphonidae
Theromyzon tessulatum
Hirudinea
Piscicolidae
Piscicola geometra
Fish leech
Ephemeroptera
Ephemerellidae
Serratella ignita
Blue-winged Olive
Ephemeroptera
Baetidae
Baetis vernus
Medium Olive
Ephemeroptera
Caenidae
Caenis rivulorum
Mayfly
Ephemeroptera
Ephemeridae
Ephemera danica
Greendrake
Megaloptera
Sialidae
Sialis lutaria
Alderfly
Hemiptera
Corixidae
Sigara venusta
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
Coleoptera
Haliplidae
Haliplus sibiricus
Crawling water beetle Crawling water beetle local
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
Coleoptera
Elmidae
Riolus subviolaceus
Riffle beetle
Coleoptera
Scirtidae
Microcara testacea
Marsh beetle
Trichoptera
Hydropsychidae
Hydropsyche siltalai
Caseless caddis
Trichoptera
Psychomyiidae
Lype reducta
Caseless caddis
Trichoptera
Rhyacophilidae
Rhyacophila dorsalis
Caseless caddis
16
Notes
Abundance
BMWP
WHPT
36 10 2 2 11 1 1
10
8.5
4
5.9
7
5
6.5 8.3 4.4 3.7 5.2
2 11
5
3.4
5 5
4.8 5.8
5
7.4
12 2 10 1 1 69 2 7 1 1
10 4 5
6.9 5
5.8
8
5.8
7
8.1
Group
BMWP family
Species
Common name
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
Limnephilus lunatus
Cased caddis
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
Diptera
Chironomidae
Non-biting midge
Diptera
Dixidae
Dixa nebulosa
Meniscus midge
Diptera
Psychodidae
Pericoma sp.
Moth fly
Diptera
Sciomyzidae
Diptera
Simulidae
Diptera
Stratiomyidae
Soldier fly
Diptera
Tipulidae
cranefly
Diptera
Tipulidae(Pediciidae)
Others
Hydracarina
Cased caddis
Notes
Abundance
7 4 1 4 9 27 2 8 2
BMWP
WHPT
6
6.5
10
6.7
7
6.9
16 1 11 25
10
9.4
2
1.3
1 1
5
5.5
5.5
Snail-killing flies Simulium sp.
Dicranota sp.
Blackflies
cranefly
190
Water mite
17
3.6
Group
BMWP family
Others
Oligochaeta
Species
Common name
Notes
True worms
# taxa score ASPT
18
Abundance
BMWP
WHPT
56
1
2.3
47 813
31 164 5.29
34.0 174.8 5.14
Group
BMWP family
Species
Common name
Notes
Abundance
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
1 15 3 2
Mollusca
Planorbidae
Anisus leucostoma
Mollusca
Planorbidae
12
Mollusca
Planorbidae
Anisus vortex Bathyomphalus contortus
Button ramshorn Whirlpool ramshorn
Mollusca
Valvatidae
Valvata cristata
Mollusca
Valvatidae
Valvata piscinalis
Flat valve snail Common valve snail
Mollusca
Ancylidae
Ancylus fluviatilis
River limpet
Mollusca
Sphaeridae
Pisidium sp.
Pea mussel
Crustacea
Asellidae
Asellus aquaticus
Water slater
Crustacea
Gammaridae
Gammarus pulex
Freshwater shrimp
Hirudinea
Erpobdellidae
Erpobdella octoculata
Leech
Hirudinea
Erpobdellidae
Leech
Hirudinea
Glossiphonidae
Trocheta subviridis Glossiphonia complanata
Hirudinea
Glossiphonidae
Helobdella stagnalis
Leech
BMWP
WHPT
Manor Farm
5
5.4
3
2.7
3
3.6
3
3.0
2 7 1 125 638 62
3
3.1
6
3
5.8 4.4 0.8 4.6 2.0
1 2
3
3.4
Twisted ramshorn
Leech
19
16
3 3 6
Group
BMWP family
Species
Common name
Notes
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 luctuosa
Mayfly
Ephemeroptera
Caenidae
Caenis rivulorum
Mayfly
Ephemeroptera
Ephemeridae
Ephemera danica
Greendrake
Ephemeroptera
Heptageniidae
Rithrogena semicolorata
Upright
Hemiptera
Gerridae
Gerris sp.
Water skater
Hemiptera
Veliidae
Velia caprai
Coleoptera
Haliplidae
Haliplus sibiricus
Water cricket Crawling water beetle
Coleoptera
Haliplidae
Haliplus sp.
Crawling water beetle
Coleoptera
Dytiscidae
Oreodytes sanmarkii
Diving beetle
Coleoptera
Hydrophilidae
Helophorus sp.
Scavenger water beetle
Coleoptera
Elmidae
Elmis aenea
Riffle beetle
Coleoptera
Elmidae
Limnius volckmari
Riffle beetle
Coleoptera
Scirtidae
Microcara testacea
Marsh beetle
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
Abundance
BMWP
WHPT
2
20
local
124 77 26 1 82 9 1 1
10
9.0
4
7.2
7
6.5
10 5
8.3 8.5 5.2
1 1 1 1 64 9 1 94 1 3 1 31
5
3.6
10
4.5 5.8 5
7.4
6.9 5
7.2
7
8.1 7.8
6
6.5
Group
BMWP family
Species
Common name
Trichoptera
Hydroptilidae
Ithytrichia sp.
Cased caddis
Trichoptera
Hydroptilidae
Oxyethira sp.
Cased caddis
Trichoptera
Leptoceridae
Adicella reducta
Long-horned caddis
Trichoptera
Limnephilidae
Limnephilus lunatus
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
Diptera
Chironomidae
Non-biting midge
Diptera
Ephydridae
Shore fly
Diptera
Muscidae
Limnophora riparia
Stable fly
Diptera
Psychodidae
Pericoma sp.
Moth fly
Diptera
Sciomyzidae
Diptera
Simulidae
Diptera
Stratiomyidae
Soldier fly
Others
Hydracarina
Water mite
Others
Oligochaeta
True worms
Notes
Abundance
1 3 1 5 1 2
Cased caddis
BMWP
WHPT
10
6.7
7
5.9
32 1 35 25 3 1 8
10
10.3
10
8.9 5.5
2
1.3
76 3 24 36
5
1
2.3
53 1675
29 160 5.52
38.0 204.8 5.39
4.4 4.0 4.5
Snail-killing flies Simulium sp.
Blackflies
# taxa score ASPT
21
6.1 3.6