View
1
Download
0
Category
Preview:
Citation preview
Consultancy
Final report: Environmental pressures impacting riverfly populations. Aquascience Consultancy: Nov. 2013 AQC22/Salmon & Trout Association.
1
Completed on the 21st November 2013
Dr. Nick Everall MIFM C Env ℡ (01246) 239344
� rnaquaconsult@aol.com
ENVIRONMENTAL PRESSURES IMPACTING
RIVERFLY POPULATIONS IN UK RIVERS
Consultancy
Final report: Environmental pressures impacting riverfly populations. Aquascience Consultancy: Nov. 2013 AQC22/Salmon & Trout Association.
2
Executive Summary
� Studies of aquatic ecological condition across 4 limestone and 3 chalk rivers of ‘good ecological quality’ highlighted variable ecological and riverfly population condition when quantitative species resolution monitoring of aquatic invertebrate communities was applied.
� In general, as sediment, organic and nutrient impact signatures decreased across all of the 7 studied rivers there was a strong association with increasing overall aquatic invertebrate abundance and species richness. In turn these improvements in the general ecological condition of the study watercourses were supported by a rise in both general riverfly and specific up-winged fly richness. Many of the aforementioned bioquality measures showed statistically significant increases amongst the various river case studies where sediment, organic and nutrient impact fingerprints were reduced. Conversely on rivers where these stresses increased above reference or un-polluted conditions then general riverfly and up-winged fly biodiversity declined. It was also important to note that iconic Biodiversity Action Plan riverfly species like the Southern Iron Blue (Baetis niger) and the Red Data Base Scarce Purple Dun (Paraleptophlebia werneri) were only found at a few survey sites throughout these study rivers where the organic, sediment and nutrient signatures corresponded to clean ‘reference’ watercourse conditions.
� In 3 out of the 7 river studies, flow had a variable, and in all probability,
diluting influence upon the sediment, organic and total reactive phosphorous impact signatures detected. Conversely, by inference it should therefore be noted that over abstraction would both compound the impacts of the key identified stresses associated with riverfly demise and although there was little evidence from these studies, flow was known to directly influence the invertebrate community composition by itself.
� From the initial river studies, Total Reactive Phosphorous Index values ≤80%
were considered to indicate macroinvertebrate communities with more TRP invertebrate indicator species than would be expected from a clean water ‘reference’ community. In the Upper River Itchen in 2013 this TRPI threshold
Consultancy
Final report: Environmental pressures impacting riverfly populations. Aquascience Consultancy: Nov. 2013 AQC22/Salmon & Trout Association.
3
associated with chemical TRP levels ≥ 0.04 mg TRP/l. However, these results were tentative based upon the relatively small independent chemical and EA GQA biological datasets from 2013 in the River Itchen. A large chemical and biological database analysis of TRP and TRPI from UK GQA sites was in progress but needed to be completed to get a better handle on this relationship.
� It should also be remembered that nutrient [TRP] level was not the only identified key stressor responsible for riverfly demise or improvement across the case study watercourses in this report. Such findings were in agreement with other workers who state that it is not unusual to encounter a range of stresses impacting UK watercourses and only by tackling all of them can the ecological integrity of river habitats be secured.
� Of the pollutant stresses associated with riverfly and up-winged fly loss, the following safety thresholds were identified from the study rivers containing reference sites with good fly diversity and numbers.
Stress Biometric threshold ~Mean chemical threshold in mg/l
Organic enrichment Saprobic index ≤1.8 BOD ≤3, <0.3 ammonia and ≥ 6 dissolved oxygen
*Nutrient enrichment (Total Reactive Phosphorous)
TRPI ≥80 Tentatively 0.04 in chalk
rivers but needs national
study results - in progress *Sedimentation PSI ≥60 (preferably ≥80) No direct equivalent Flow velocity LIFE ≥8 No direct equivalent
* N.B. Normally TRPI and PSI are reverse scales i.e. a low %score = high stress
� There was also growing evidence that river water temperature is changing in response to climate change and that aquatic organisms respond to changing thermal conditions in complex ways. Given the dependence of phenology on heat accumulation, the emergence of insects is particularly susceptible to changing temperature and can have adverse effects on freshwater insects populations Such additional thermal pressures only make it more important to identify and protect sensitive riverfly rich watercourses from other pressures, such as organic, nutrient, suspended sediment loads or hydrological changes.
� The highly resolved biological data in the case studies in this report was important in identifying fine scale shifts in ecosystem structure that served as benchmark evidence of both current subtle improvements or impacts and an ‘early warning’ system for the detection of further improvement or deterioration in ecological condition across UK rivers. The current case studies re-iterated the investigational need for the collection of quantitative species-level data wherever it is possible to provide a ‘complete’ picture when addressing management decisions about highly ecologically sensitive areas like the rivers in the case studies examined in this report.
Consultancy
Final report: Environmental pressures impacting riverfly populations. Aquascience Consultancy: Nov. 2013 AQC22/Salmon & Trout Association.
4
Contents Page no.
1. Background 5
2. Case studies 6
2.1 Limestone rivers 7
2.1.1 The River Dove in Staffordshire (2009-2013) 7
2.1.2 The River Manifold in Staffordshire (2009-2013) 10
2.1.3 The River Hamps in Staffordshire (2009-2013) 12
2.1.4 The River Wye in Derbyshire (2013) 15
2.2 Chalk rivers 17
2.2.1 The Bourne Rivulet in Hampshire (1989-2013) 18
2.2.2 The River Test in Hampshire (1995-2013) 23
2.2.3 The River Itchen in Hampshire (1995-2013) 27
2.2.4 Historic perspectives and wider pressures for riverfly populations 28
Acknowledgements
References
Appendices
Appendix 1 - Details of biometric testing used on the species macroinvertebrate community data across the various river case studies highlighted in this report.
Study Limitations
This report was prepared by Dr. Everall of Aquascience Consultancy at the request of Paul Knight of the Salmon & Trout Association. This report has been produced by Aquascience Consultancy within the terms of the contract with the client and taking account of the resources devoted to it by agreement with the client. We disclaim any responsibility to the client and others in respect of any matters outside of the specific scoping of this report. This report is confidential to the client, and we accept no responsibilities to third parties to whom this report, or any part thereof, is made known. Any such party relies on the contents of the report at their own risk. Any changes to any current UK and international ecotoxicological standards outlined in this report may cause the opinion, advice and conclusions set out in this report to become inappropriate or incorrect.
Consultancy
Final report: Environmental pressures impacting riverfly populations. Aquascience Consultancy: Nov. 2013 AQC22/Salmon & Trout Association.
5
1. Background
While there have been great strides in improving the ecological quality of many UK rivers over the last 50 years, relentless population expansion is putting more pressure upon finite aquatic resources through e.g. the direct abstraction of water for drinking water, the disposal of human waste and associated intensity of agricultural operations impinging upon our wetlands. Indeed, many of these issues are variably responsible for why, in the UK, fewer than 40% of surface waters were in good ecological status in 2009, at an early stage of the Water Framework Directive and river basin management plans with only 5% more expected to reach good ecological status by 2015. Under pinning robust ‘good ecological status’ are the aquatic macroinvertebrates which form a fundamental component of watercourse ecosystems such that increasing the invertebrate abundance and diversity strengthens the ecological integrity of watercourses (Spänhoff and Arle, 2007). Amongst these integral invertebrate components of the aquatic ecosystem are the riverfly groups of the Ephemeroptera mayflies (Ephemeroptera), stoneflies (Plecoptera) and caddis flies (Trichoptera). These species-rich orders represent a significant proportion of aquatic invertebrate biodiversity (Chadd and Extence, 2004 and Hering et al., 2009) and an important food-chain resource for other organisms; especially fish (Dineen et al., 2007). Amongst these riverfly groups, the most pollutant sensitive and economically important riverflies identified for many salmon, trout and grayling fly fishing rivers are the up-winged flies or mayflies (Wright et. al., 1996 & Bennett and Gilchrist, 2010). Any aquatic entomologist, angler or non-angler over the age of 50 will tell you that a trip down the local river 50 years ago involved having to clear the windscreen of all the collected riverflies. Many automobiles at that time were actually fitted with insect deflector’s designed to reduce this then commonplace problem. Such observations can easily be dismissed as hearsay evidence of the past quantum of riverfly populations but they are supported by more recent scientific facts of a decline in species rich riverfly groups across a number of UK watercourses in recent decades (Frake and Hayes, 2001, Bennett and Gilchrist, 2010 and Everall, 2013b). To understand potential riverfly loss and to provide facts for evidence based policies or practical in-stream management to deliver solutions then aquatic biological monitoring data bases are required that reverse the trend in UK Regulatory biomonitoring practices across our rivers in recent decades. Regulatory biomonitoring of watercourses in the UK over the last 30 years has progressively moved towards more broad brush semi-quantitative family level analysis of our aquatic invertebrate communities but this has insufficient taxonomic and abundance resolution to enable the assessment of either spatial or temporal trends in e.g. riverfly species biodiversity. Over the last decade it has been more widely accepted that aquatic faunal data often needs to be resolved to species level to adequately fulfil operational and legislative obligations for river management and conservation purposes (Arscott et al., 2006, Everall, 2010, Monk et. al., 2011 and Mainstone, 2012). Combined with the collection of more detailed aquatic invertebrate community data across a number of UK rivers there has been the recent advances in biometric
Consultancy
Final report: Environmental pressures impacting riverfly populations. Aquascience Consultancy: Nov. 2013 AQC22/Salmon & Trout Association.
6
fingerprinting which provide causal stress signatures responsible for any detected impacts or improvements in aquatic ecological quality. For example, municipal and agricultural impacts in receiving watercourses often manifest themselves through the impacts of organic pollution, nutrient enrichment and siltation (Hellawell, 1986, Extence et. al., 2010 and Everall, 2010). Siltation can now be biologically assessed using a sediment-sensitive macroinvertebrate metric, PSI (Proportion of Sediment-sensitive Invertebrates) at family or species level (Extence et. al., 2010) and this acts as a proxy to describe temporal and spatial impacts of sediment inputs to watercourses. Organic enrichment has been assessed using species level Saprobic indexing with macroinvertebrates for over 50 years in the rest of Europe (Pantle and Buck, 1955, Zelinka and Marvan, 1966 and Hellawell, 1986) but was not widely utilised in the UK because routine Regulatory biological monitoring moved progressively away from species level work in this country, until very recent years. Many studies have compared the results of different benthic macroinvertebrate metrics used to assess the impact of organic pollution (Hellawell, 1986, Calow & Petts, 1993 and Hauer & Lamberti, 1996). The Saprobic Index was found to work better than the Average Score Per Taxon or ASPT (Armitage et. al., 1983), utilised in the Regulatory UK RIVPACS based monitoring, as a measure of watercourse stress gradients in those European countries where macro-invertebrates were subject to a species as opposed to a lower family level of macroinvertebrate community profiling (Sandin and Hering, 2004). Phosphorous impacts upon the receiving ecology can now be assessed from aquatic invertebrate community composition using the Total Reactive Phosphorous or TRP Index (Everall, 2005, Everall, 2010, Everall and Farmer, 2012 and Everall, 2013b & c) which was developed in collaboration with Paisley et. al. (2003 and 2011) from phosphorous indicator work in UK watercourses using macroinvertebrates. Initial trials of the macroinvertebrate TRP Index have produced statistically comparable results with the Trophic Diatom Index (TDI) which, along with the higher plant (macrophyte) based Mean Trophic Rank, remained the key regulatory e.g. Water Framework Directive (WFD) biometrics used to assess nutrient enrichment in watercourses. The evidence for both riverfly population demise and the causative pressure sensitive stresses are provided in this report across a number of varied aquatic ecological investigations of UK rivers where the rarer quantitative species level aquatic faunal data was available and multi-biometric analyses had been undertaken. It is not, and because of the relative lack of species invertebrate community data, cannot be a definitive study at this point but it starts to provide the much needed resolution of study that highlights a number of causes of riverfly population gain and decline in some UK rivers in recent decades. Any field identified stresses exhibiting a mechanistic link with riverfly population impacts, as with all good ecological studies, will need to be followed up by controlled ecotoxicological laboratory testing to evaluate the quantum of potential cause and effect relationships.
Consultancy
Final report: Environmental pressures impacting riverfly populations. Aquascience Consultancy: Nov. 2013 AQC22/Salmon & Trout Association.
7
2. Case studies
Longer-term and even ‘snap-shot’ species datasets on UK rivers are relatively rare but they are what is required to attempt to tease out both where wider aquatic ecological condition and in the case of this study, up-winged fly populations may or may not be depauperate and what environmental stresses associate with such conditions. The majority of background and backbone Regulatory biomonitoring sites on our rivers in England and Wales are referred to by the Environment Agency as General Quality Assessment (GQA) sites for aquatic macroinvertebrate assessments or other biological and chemical sampling. To date the biological macroinvertebrate community data that has been collected has not been routinely taken to a species level of analysis for the purposes of e.g. WFD assessment and so it is fundamentally unsuitable to try and assess mayfly or few other species richness and abundance from such a dataset. It should be stressed that the Regulatory monitoring philosophy has changed in recent years with a move back to more species level data collection but alas this did not currently provide a large a spatial and temporal national GQA dataset to interrogate for this study. The relatively new Angler’s Riverfly Monitoring scheme is equally data limited in this respect because it was designed as a simple pollution sentinel on our rivers by analysing a bespoke group of mayfly, caddis and stoneflies to group or family level. These monitoring data synopses were not a criticism of historic routine biological quality or riverfly monitoring in the UK because these monitoring tools were fit for the purposes that they were designed for at that time. However, family level analysis of mayfly or any other riverfly populations would at best be crude and at worst, potentially misleading. The difference in the resolution of ecological condition assessment and the associated pressure-sensitive trait analysis between family and species level macroinvertebrate data can be large (Everall and Farmer, 2012). Furthermore, river SSSI (and SAC) networks are designated for their river habitat by including their characteristic biological communities (Mainstone and Hatton-Ellis, 2011). On this basis it appeared outwardly counter-intuitive to consider any general or pressure specific ecological indicators that operate at less than species level if the indicators are to be sufficiently sensitive to loss of fishery and conservation value resulting from anthropogenic impacts. The following are the findings from a number of species level macroinvertebrate case studies in SAC and non-SAC rivers throughout the UK in recent years. 2.1 Limestone rivers
2.1.1 The River Dove in Staffordshire (2009-2013)
All the sampling techniques, raw data and analytical methodologies employed in studying riverfly populations through the Upper River Dove catchment in 2009-2013 can be found in Everall (2010). A large spatial study of the Upper River Dove catchment in Derbyshire-Staffordshire was undertaken in 2009 by Natural England (Everall, 2010) as a benchmark of aquatic ecological and pollutant condition to both target Catchment Sensitive Farming investment and measure post-investment watercourse condition respectively. The graph overleaf is typical of the sort of detail on mayfly population status through the River Dove in 2009 that is available through the benchmark report (Everall, 2010).
Consultancy
Final report: Environmental pressures impacting riverfly populations. Aquascience Consultancy: Nov. 2013 AQC22/Salmon & Trout Association.
8
Mayfly profiles in River Dove in Autumn 2009
0
50
100
150
200
250
Site 1
Site 3
Site 5
Site 7
Site 1
0
Site 1
1
Site 1
2
Site 1
3
Site 1
5
Site 1
6A
Site 1
8
Site 2
0
Site 2
1
Site 2
2A
Site 2
3
Site 2
3B
Site 2
5
Site 2
5B
Nu
mb
er
pe
r 3
min
kic
k-s
we
ep
sam
ple
The Mayfly
Blue-winged Olive
Ditch Dun
Turkey Brown
Olive Upright
Brook Dun
Other flat bodied
Yellow May Dun
The mayfly (Ephemera danica) and the blue-winged olive (Serratella ignita) were dominant in only modest numbers through the River Dove in May 2009 and they were replaced in dominance by the olive upright (Rhithrogena semicolorata) in the upper reaches of the river with some nymphs shown below.
Ephemera danica Serratella ignita Rhithrogena semicolorata
There are also a number of Environment Agency reports documenting the details of the ongoing study and findings (Everall, 2013d) from which the following findings relating to the longer-term riverfly population status have been taken. The graph overleaf shows a synopsis of the general aquatic faunal condition (R and abundance) with the more specific riverfly (No. of EPT) and up-winged fly or mayfly (No. of UWF) plus associated patterns of pressure sensitive stresses in the watercourse e.g. siltation (PSI) and flow velocity (LIFE) fingerprints in the invertebrate communities.
Consultancy
Final report: Environmental pressures impacting riverfly populations. Aquascience Consultancy: Nov. 2013 AQC22/Salmon & Trout Association.
9
R (
specie
s r
ichness)
EP
T (
no. m
ay-c
addis
-sto
nefly)
UW
F (
no. m
ayflie
s)
S (
org
anic
pollu
tion)
LIF
E (
flow
)
*PS
I (s
ilt)
*TR
PI ([
P] enrichm
ent)
A (
faunal abundance x
103 m
-2)
2009
2011
2013
0
10
20
30
40
50
60
70
80
Biometric quality and stress
gradient ↑
Measure
Year (Spring)
Aquatic ecological condition and key watercourse stresses in the River Dove near Hartington 2009-
2013
2009
2010
2011
2012
2013
*Please note that both Percentage Sedimentation (PSI) and Total Reactive Phosphorous indices have been inverted because low percentage values traditionally represent high sediment and total reactive phosphorous signatures in the ecology but this was considered counter-intuitive to the reader. High percentage values now represent high biometric stress gradients in the graphs throughout this report unless stated otherwise.
The key findings from this ~5 year study was that as flow velocity slightly increased, sediment and nutrient [P] levels dissipated between 2009-2013 in association with a marked increase in overall riverine invertebrate abundance and species richness which was under pinned by a rise in both general riverfly and specific up-winged fly richness. Many of the aforementioned biometrics showed statistically significant (P≤ 0.05) increases over the study period from 2009 to 2013 (Everall, 2013d) as shown in the graph below.
Ecological quality in upper River Dove at Beresford Dale from 2009 to 2013
0
500
1000
1500
2000
2500
3000
R. Dove Spring
2009
R. Dove Autumn
2009
R. Dove Autumn
2011
R. Dove Spring
2012
R. Dove Autumn
2012
R. Dove Spring
2013
BM
WP
sco
re a
nd
fau
nal ab
un
dan
ce in
no
. m
-2 (9
5%
C.L
)
0
10
20
30
40
50
60
Sp
ecie
s r
ich
ness (
R)
m-2
(95%
C.L
.)
BMWP
Faunal abundance no. m-2
R (species richness)
Consultancy
Final report: Environmental pressures impacting riverfly populations. Aquascience Consultancy: Nov. 2013 AQC22/Salmon & Trout Association.
10
The previous results for the River Dove are temporal patterns over a fixed spatial point but the same temporal associations were evident amongst the other sample sites in the River Dove long-term CSF study (Everall, 2013d). The new Total Reactive Phosphorous Index (TRPI) using macroinvertebrate community signatures and developed by Everall (2005) from indicator taxa highlighted in Paisley et. al. (2003 and 2011) will be mentioned throughout this report. In light of this it appeared prudent to highlight the results of an interpolation of Trophic Diatom Index (TDI) and TRPI results for all of the Upper River Dove sites studied in 2009-2010 in the graph below.
Trophic Diatom Index (TDI - diatoms) versus Total Reactive Phosphorous Index (TRPI -
macroinvertebrates) at sites through the Upper River Dove in 2009-2010
R2 = 0.4379
R2 = 0.3606
R2 = 0.406
0
10
20
30
40
50
60
70
80
d/s junc
tion
with
R. M
anifo
ld
Dov
edale
nr. T
horp
e Cloud
Dov
edale
Milld
ale
Wolfsco
te D
ale
– Gyp
sy B
ank
Site 1
1A
Site 1
2A
u/s Har
tingt
on C
ream
ery
Pilsbu
ry
Und
er W
hittle
Begga
r Brid
ge
Site 2
0A
Botto
n fo
otpa
th fr
om H
ollin
scloug
h
Site 2
2B
Brook
from
Ten
terh
ill
u/s Bra
ndside
and
oth
er b
rook
s
Site 2
5A
Axe E
dge
Sample site for diatoms and macroinvertebrates
TD
I% a
nd
TR
PI% TDI
TRPI Spring
TRPI Autumn
Linear (TDI)
Linear (TRPI Spring )
Linear (TRPI Autumn)
Higher TDI values represent higher nutrient enrichment but lower TRPI values counter-intuitively represent higher [TRP] enrichment and unlike the other graphs in this report they have been left in their original formatting in the graph above. TDI and TRPI in this test therefore produced highly comparable nutrient signatures in terms of sensitivity and slope across the chosen study sites.
2.1.2 The River Manifold in Staffordshire (2009-2013)
All the sampling techniques, raw data and analytical methodologies employed in studying riverfly populations through the Upper River Dove catchment in 2009-2013 can be found in Everall (2010). The graph overleaf is typical of the sort of detail on mayfly population status through the River Manifold in 2009 that is available through the benchmark report (Everall, 2010).
Consultancy
Final report: Environmental pressures impacting riverfly populations. Aquascience Consultancy: Nov. 2013 AQC22/Salmon & Trout Association.
11
Mayfly profile in the River Manifold in Spring 2009
0
50
100
150
200
250
Site 1
Site 2
Site 3
Site 4
A
Site 4
Site 5
A
Site 5
Site 6
Site 7
Site 8
Site 9
Site 1
0
Site 1
0A
Site 1
0B
Site 1
0C
Site 1
1
Site 1
2
Site 1
3
Site 1
4
Site 1
4A
Site 1
5
Site 1
7
Site 1
7A
Site 1
8
Nu
mb
er
per
3 m
in k
ick-s
weep
sam
ple
Mayfly
Blue-winged Olive
Ditch Dun
Turkey Brown
Olive Upright
Large Brook Dun
Other flat bodied
Yellow May Dun
Flat bodied mayflies (Ecdyonurus and Rhithrogena semicolorata) were dominant in modest numbers through the River Manifold in May 2009 and were complimented in dominance by the blue-winged olive (Serratella ignita) towards the upper reaches of the river with some nymphs shown below.
Ecydonorus venosus/dispar/torrentis Rhithrogena semicolorata Serratella ignita There are also a number of Environment Agency reports documenting the details of the ongoing study and findings (Everall, 2013d) from which the following findings relating to the longer-term riverfly population status have been taken. The graph overleaf shows a synopsis of the general aquatic faunal condition (R and abundance) with the more specific riverfly (No. of EPT) and up-winged fly or mayfly (No. of UWF) plus associated patterns of pressure sensitive stresses in the watercourse e.g. siltation (PSI) and flow velocity (LIFE) fingerprints in the invertebrate communities.
Consultancy
Final report: Environmental pressures impacting riverfly populations. Aquascience Consultancy: Nov. 2013 AQC22/Salmon & Trout Association.
12
2009
20120
10
20
30
40
50
60
70
80
B io met r ic qualit y and
st ress grad ient ↑
M easure
Y ear ( Sp ring)
Aquatic ecological condition and key watercourse stresses in the River Manifold
near Longnor 2009-2013
2009
2011
2012
2013
*Please note that both Percentage Sedimentation (PSI) and Total Reactive Phosphorous indices have been inverted because low percentage values traditionally represent high sediment and total reactive phosphorous signatures in the ecology but this was considered counter-intuitive to the reader. High percentage values now represent high biometric stress gradients in the graphs throughout this report unless stated otherwise.
The key findings from this ~5 year study was that as flow velocity slightly increased, sediment and nutrient [P] levels dissipated between 2009-2013 along with a marked increase in overall riverine invertebrate abundance and species richness which was under pinned by a rise in both general riverfly and specific up-winged fly richness. Many of the aforementioned biometrics showed statistically significant (P≤ 0.05) increases over the study period from 2009 to 2013 (Everall, 2013d). The previous results for the River Manifold are temporal patterns over a fixed spatial point but the same temporal associations were evident amongst the other sample sites in the River Manifold long-term CSF study (Everall, 2013d). 2.1.3 The River Hamps in Staffordshire (2009-2013)
All the sampling techniques, raw data and analytical methodologies employed in studying riverfly populations through the Upper River Dove catchment in 2009-2013 can be found in Everall (2010). The graph overleaf is typical of the sort of detail on mayfly population status through the River Hamps in 2009 that is available through the report (Everall, 2010).
Consultancy
Final report: Environmental pressures impacting riverfly populations. Aquascience Consultancy: Nov. 2013 AQC22/Salmon & Trout Association.
13
Mayfly profiles in the River Hamps in Spring 2009
0
50
100
150
200
250
Site 1 Site 2 Site 3 Site 4 Site
4A
Site
5A
Site 6 Site 7 Site 8 Site 9 Site
10
Site
11
11A 11B Site
11C
Site
12
Site
14
Nu
mb
er
per
3 m
in k
ick-s
weep
sam
ple
Mayfly
Blue-winged Olive
Ditch Dun
Turkey Brown
Olive Upright
Large Brook Dun
Other flat bodied
Yellow May Dun
The R. Hamps had comparable mayfly numbers to the River Manifold but dominated by the blue-winged olive (Seratella ignita) and the olive upright (Rhithrogena
semicolorata) plus a marked presence of the Ditch Dun (Haprophlebia fusca) at various main river sites in May (September) 2009.
There are also a number of Environment Agency reports documenting the details of the ongoing study and findings (Everall, 2013d) from which the following findings relating to riverfly population status have been taken. The graph overleaf shows a synopsis of the general aquatic faunal condition (R and abundance) with the more specific riverfly (No. of EPT) and up-winged fly or mayfly (No. of UWF) plus associated patterns of pressure sensitive stresses in the watercourse e.g. siltation (PSI) and flow velocity (LIFE) fingerprints in the invertebrate communities.
Consultancy
Final report: Environmental pressures impacting riverfly populations. Aquascience Consultancy: Nov. 2013 AQC22/Salmon & Trout Association.
14
R (
sp
ecie
s r
ich
ne
ss)
EP
T (
no
. m
ay-c
ad
dis
-sto
ne
fly)
UW
F (
no
. m
ayflie
s)
S (
org
an
ic p
ollu
tio
n)
LIF
E (
flo
w)
*PS
I (s
ilt)
*TR
PI
([P
] e
nrich
me
nt)
A (
fau
na
l a
bu
nd
an
ce
x 1
03
m-2
)
2009
20120
10
20
30
40
50
60
70
80
90
Biometric quality and stress
gradient ↑
Measure
Year (Spring)
Aquatic ecological condition and key watercourse stresses in the River Hamps near
Onecote 2009-2013
2009
2011
2012
2013
*Please note that both Percentage Sedimentation (PSI) and Total Reactive Phosphorous indices have been inverted because low percentage values traditionally represent high sediment and total reactive phosphorous signatures in the ecology but this was considered counter-intuitive to the reader. High percentage values now represent high biometric stress gradients in the graphs throughout this report unless stated otherwise.
Many of the overall increases in riverfly and specific mayfly species richness in response to reduced organic, nutrient and sediment loads across the River Dove, Manifold and Hamps between 2009 and 2013 also contained specific increase in the abundance of riverflies as shown in the example graph below for the River Hamps.
Relative abundance of mayfly nymphs in Mixon Hay Brook below farms between 2009 and 2013
0
100
200
300
400
500
600
700
800
Spring 2009 Autumn 2009 Autumn 2011 Spring 2012 Autumn 2012 Spring 2013
Year/season
Nu
mb
er
of
ny
mp
hs 3
min
-1 k
ick
/sw
eep
sam
ple
B. scambus
Ecdyonorus sp.
Rhithrogena sp.
Baetis scambus Ecdyonorus sp. Rhithrogena sp.
Consultancy
Final report: Environmental pressures impacting riverfly populations. Aquascience Consultancy: Nov. 2013 AQC22/Salmon & Trout Association.
15
The key findings from this ~5 year study was that, irrespective of flow regime, as sediment and nutrient [P] levels dissipated between 2009-2013 there was a marked increase in overall riverine invertebrate abundance and species richness which was under pinned by a rise in both general riverfly and specific up-winged fly richness. Many of the aforementioned biometrics showed statistically significant (P≤ 0.05) increases over the study period from 2009 to 2013 (Everall, 2013d). The previous results for the River Manifold are temporal patterns over a fixed spatial point but the same temporal associations were evident amongst the other sample sites in the River Hamps long-term CSF study (Everall, 2013d). It should also be noted that now rare and Biodiversity Action Plan (BAP) riverfly species like the Southern Iron Blue (Baetis niger) and iconic upland species like the Large Stonefly Dinocras
cephalotes were only found at the upper survey sites in this studies of the River Dove, River manifold and River Hamps where organic, sediment and nutrient signatures corresponded to clean reference watercourse conditions (Everall, 2010). 2.1.4 The River Wye in Derbyshire (2013)
All the sampling techniques, raw data and analytical methodologies employed in studying riverfly populations through the Upper River Wye catchment in 2013 can be found in Everall (2013b). The graph below was typical of the sort of detail on mayfly population status through the River Wye in 2013 that was available through the report (Everall, 2013b).
Ecdyonuru
s s
p.
Rhithro
gena s
p.
Ephem
era
danic
a
Para
lepto
phle
bia
subm
arg
inata
Serr
ate
lla ignita
Caenis
riv
ulo
rum
or
Caenis
luctu
em
Baetis s
cam
bus
Baetis r
hodani
Baetis m
uticus
Baetis fuscatu
s
BA
P B
aetis n
iger
Site 8 d/s Buxton - Spring 2013
Site 7 Below Topley Pike - Spring 2013
Site 6 d/s Blackwell cottages - Spring 2013
Site 5 u/s Monksdale - Spring 2013
Site 4 d/s Monksdale - Spring 2013
Site 3 d/s Tideswell Brook - Spring 2013
Site 2 d/s Litton Mill - Spring 2013
Site 1 d/s Cressbrook Mill - Spring 2013
d/s R. Lathkill - Spring 2013
Mayfly species
River Wye survey site
Biodiversity of up-winged flies through River Wye (through SSSI reaches 70 & 71) in Spring of 2013
The key findings from the 2013 study in the River Wye was that, irrespective of flow regime, as sediment and nutrient [P] levels dissipated down the river corridor there was a marked increase in overall riverine invertebrate abundance and species richness which was under pinned by a rise in both general riverfly and specific up-winged fly richness as shown in the graph overleaf.
Flow �
Consultancy
Final report: Environmental pressures impacting riverfly populations. Aquascience Consultancy: Nov. 2013 AQC22/Salmon & Trout Association.
16
Sediment (PSI) and phosphorous (TRPI) enrichment with up-winged fly species richness (UWF
Species) through the River Wye below Buxton in the Spring of 2013
0
10
20
30
40
50
60
70
80
90
100
8 d/s Buxton 7 Below
Topley Pike
6 d/s
Blackwell
cottages
5 u/s
Monksdale
4 d/s
Monksdale
3 d/s
Tideswell
Brook
2 d/s Litton
Mill
1 d/s
Cressbrook
Mill
d/s
confluence
with R.
Lathkill
To
tal R
eacti
ve P
ho
sp
ho
rou
s I
nd
ex (
TR
PI)
an
d P
erc
en
tag
e
Sed
imen
tati
on
In
dex (
PS
I) (
±95%
C.L
.)
0
2
4
6
8
10
12
No
. U
p-w
ing
ed
Fly
Sp
ecie
s
TRPI
PSI
UWFSpecies
The spatial pattern for an increasing signature of [P] moulding of the receiving invertebrate communities in the River Wye in 2013 was very similar to the pattern for mild organic enrichment (S for species Saprobic index) in the graph below.
Organic (S) and phosphorous (TRPI) enrichment with total aquatic fauanl species richness (R)
through the River Wye below Buxton in the Spring of 2013
0
10
20
30
40
50
60
70
80
90
100
8 d/s Buxton 7 Below
Topley Pike
6 d/s
Blackwell
cottages
5 u/s
Monksdale
4 d/s
Monksdale
3 d/s
Tideswell
Brook
2 d/s Litton
Mill
1 d/s
Cressbrook
Mill
d/s
confluence
with R.
Lathkill
To
tal R
eacti
ve P
ho
sp
ho
rou
s In
dex (
TR
PI)
an
d a
qu
ati
c f
au
nal
sp
ecie
s r
ich
ness (
R)
(±95%
C.L
.)
0
0.5
1
1.5
2
2.5
Sa
pro
bic
in
dex (
S)
(±95%
C.L
.)
TRPI
R
S
It is important to start to understand that while we are not talking about marked pollution impacts in most of these studies we are starting to unravel the impacts of relatively mild organic (ammonia, BOD ..), inorganic (reactive phosphorous ..) and sediment upon riverfly richness and abundance in UK rivers. Small increases or reductions in organic, nutrient and sediment load, under the marked pollution radar, associated respectively with both loss and gain of aquatic riverfly species richness and abundance in the River Dove, Manifold, Hamps and Wye studies from 2009-2013. The biometric, chemically measured and inferred BOD levels in the study reaches of the River Dove, Manifold and Hamps all showed a reduction in BOD from ~1-6 mg/l
Consultancy
Final report: Environmental pressures impacting riverfly populations. Aquascience Consultancy: Nov. 2013 AQC22/Salmon & Trout Association.
17
to 1-2 mg/l from 2009 to 2013 (Everall, 2013d). This data was very interesting because increased abundances of taxa sensitive to organic pollution were also correlated with reductions in mean BOD from around 1.6 mg/l to 1.3 mg/l in river studies by Durance and Ormerod (2009). Similarly, in an analysis of environmental change in the Wye catchment, Herefordshire, Clews and Ormerod (2009) found that observed improvements in the macroinvertebrate community over the period 1989-2000 were best explained by reductions in the level of organic pollution, from around 1.5mg/l mean BOD to around 0.7 mg/l. In a recent study of nearly 600 Danish streams over an 11-year period, Friberg and others (2010) also observed strong relationships between the abundance of certain pollution-sensitive invertebrate taxa and mild levels of organic enrichment, which were not explicable through inter-correlation with key habitat variables. The stonefly genus Leuctra showed the highest sensitivity, with occurrence declining sharply at BOD levels above 1.6 mgl-1. Further study of the 2009 species macroinvertebrate community data from the River Dove indicated that ~13 macroinvertebrate species were lost in moving up one ‘band of organic load’ under mild (nutrient enriched) to critical (mildly organically polluted) field conditions with the bands of organic load highlighted below from Everall and Farmer (2012).
Saprobic Index Degree of organic load Usual mean BOD in mg/l
2.7 - 3.2 Strongly polluted 7-13 2.3 - <2.7 Critical 5-10 1.8 - <2.3 Mild 2-6 1.5 - <1.8 Small 1-2
Such correlative analyses do not provide absolute proof of cause and effect, but the lack of clear relationships with other possible environmental influences from other workers and the findings of our current studies in the upper River Dove, Manifold, Hamps and Wye strongly suggested a mechanistic link between riverfly loss or gain with combined organic (BOD ..), nutrient ([TRP] and sediment levels in these watercourses. The next step would be to test the field observations and hypotheses about the lesser understood stresses of sediment and nutrient in the laboratory under controlled conditions e.g. the impacts of varied independent fine (inert) sediment, TRP and combined sediment/TRP upon up-winged fly egg survival. A costed research proposal was submitted by the author to the Environment Agency via the Angling Trust in 2012 but there has been no funding found to enable such studies to date. It should also be noted that the now rare and Biodiversity Action Plan (BAP) riverfly species of the Southern Iron Blue (Baetis niger) was only found at the survey sites in the River Wye where organic, sediment and nutrient signatures corresponded to clean reference watercourse conditions (Everall, 2013b). 2.2 Chalk rivers
It should be noted that there was less species and fully quantitative level data on macroinvertebrate communities of the chalk rivers than that for the limestone river’s at present but this is starting to be addressed by the Environment Agency and numerous independent riparian Stakeholders in recent years.
Consultancy
Final report: Environmental pressures impacting riverfly populations. Aquascience Consultancy: Nov. 2013 AQC22/Salmon & Trout Association.
18
2.2.1 The Bourne Rivulet in Hampshire (1989-2013)
All the sampling techniques, raw data and analytical methodologies employed in studying riverfly populations through the Bourne Rivulet catchment from 1989-2013 can be found in Everall (2013b). A large temporal and spatial desk top study of essentially family level data of the Bourne Rivulet was undertaken in 2013 by the Bright Waters Trust (Everall, 2013c) as a hind cast understanding of aquatic ecological and pollutant condition of the watercourse to date. In the Bourne Rivulet, family level biometric data indicated that mild organic pollution, nutrient and sediment had all spatially and temporally had a hand in moulding the ecological condition of the watercourse over the last ~25 years as shown in the graphs overleaf which examine just the organic and sediment signatures in the two upper rivulets.
Consultancy
Final report: Environmental pressures impacting riverfly populations. Aquascience Consultancy: Nov. 2013 AQC22/Salmon & Trout Association.
19
Bourne West Rivulet ‘reference’ site 1989-2013
Organic enrichment and siltation in Bourne West Rivulet 200m downstream SMB cress farm and
factory (EA data 1989-*2013) *EA/Aquascience Consultancy joint data
0
10
20
30
40
50
60
70
80
90
100
8.11
.89
17.1
.90
24.4
.90
10.7
.90
2.10
.90
7.1.
9129
.4.9
124
.7.9
1
23.1
0.91
15.1
.92
28.4
.92
6.7.
925.
10.9
226
.1.9
321
.4.9
36.
7.93
6.10
.93
6.4.
9429
.9.9
421
.4.9
520
.6.9
5
30.1
0.95
22.5
.96
13.7
.96
16.9
.96
30.1
0.97
13.5
.98
19.1
0.98
25.1
.99
10.4
.99
6.6.
9925
.6.0
316
.1.0
411
.5.0
4
20.1
0.04
16.9
.05
7.3.
0621
.4.0
6
16.1
1.06
29.4
.07
2.11
.07
28.5
.08
29.1
1.08
30.1
1.09
4.6.
13
Sample date
Sil
tati
on
(P
SI)
0.00
0.50
1.00
1.50
2.00
2.50
3.00
Org
an
ic e
nri
ch
me
nt
(Sa
pro
bic
in
de
x)
PSI
Saprobic index
The Bourne West Rivulet was long regarded by the Environment Agency and predecessor organisations (Soulsby, 1985) as a surrogate reference i.e. un-impacted site for this headwater reach of the Bourne Rivulet. However, in organic enrichment terms this was clearly not the case and subject as it has been to some degree of discharge-seepage from the St. Mary Bourne cress farm and upstream CSO’s this watercourse should not be organic enrichment benchmarked using West Rivulet Saprobic data. The Bourne West Rivulet had clearly long been subject to organic enrichment with a receiving watercourse fauna indicating a predominance of fauna tolerant of organic enrichment (betamesosaprobic) from 1989-2005. Post-2005, following EA instigated operational and discharge changes at St. Mary Bourne cress farm, there was a period of gradual recovery in the organic moulding of the aquatic fauna until 2006 when organic enrichment started to return to pre-2005 levels on what appeared to be a potentially worrying upward trend.
Un-silted
/naturally silted
Slightly silted
Moderately
silted
Silted
Heavily silted
Betamesosaprobic - moderate
organic enrichment
Consultancy
Final report: Environmental pressures impacting riverfly populations. Aquascience Consultancy: Nov. 2013 AQC22/Salmon & Trout Association.
20
Bourne East Rivulet site 1989-2013
Organic enrichment and siltation in Bourne East Rivulet 200m downstream SMB cress farm and
factory (EA data 1989-*2013) *EA/Aquascience Consultancy joint data
0
10
20
30
40
50
60
70
80
90
100
8.11
.89
17.1
.90
24.4
.90
10.7
.90
2.10
.90
7.1.
9129
.4.9
124
.7.9
1
23.1
0.91
15.1
.92
28.4
.92
6.7.
925.
10.9
226
.1.9
321
.4.9
36.
7.93
6.10
.93
6.4.
9429
.9.9
421
.4.9
520
.6.9
5
30.1
0.95
22.5
.96
13.7
.96
16.9
.96
13.5
.98
19.1
0.98
25.1
.99
10.4
.99
25.6
.03
16.1
.04
11.5
.04
20.1
0.04
16.9
.05
7.3.
0621
.4.0
6
16.1
1.06
29.4
.07
25.5
.07
2.11
.07
28.5
.08
29.1
1.08
30.1
1.09
5.5.
1223
.5.1
24.
6.13
Sample date
Silta
tio
n (
PS
I)
0.00
0.50
1.00
1.50
2.00
2.50
3.00
Org
an
ic e
nri
ch
men
t (S
ap
rob
ic i
nd
ex)
PSI
Saprobic index
The Bourne East Rivulet had clearly long been subject to more marked organic enrichment than the West Rivulet, with a receiving watercourse fauna indicating a predominance of fauna highly tolerant of organic enrichment (alpha-betamesosaprobic) from 1989-2005. Post-2005, at the time of EA instigated operational and discharge changes at St. Mary Bourne cress farm, there was a period of gradual recovery in the organic moulding of the aquatic fauna until 2012 when organic enrichment started to return to pre-2005 levels with what appeared to be a sudden upturn between 2012 and 2013.
Un-silted
/naturally silted
Slightly silted
Moderately
silted
Silted
Highly silted
Betamesosaprobic -
moderate organic
enrichment
↑ Alpha-
betamesosaprobic -
marked organic
enrichment
Consultancy
Dr. Nick Everall MIFM C Env ���� rnaquaconsult@aol.com ℡℡℡℡ 01246 239344 21
The Bourne Report (Everall, 2013c) holds a great deal more detail of all of the environmental stresses associated with changes in ecological condition of the chalk river between 1989 and 2013 but much of this is on historic Environment Agency data at a family invertebrate community level. More recent species level studies have started to provide some insight into factors affecting riverfly populations in the Bourne Rivulet. Recent species level evidence suggested that organic enrichment (~Saprobic index) from a source between Stoke and Derrydown Farm, with further organic augmentation via the Bourne East Rivulet, associated with a pervasive fingerprint of reduced aquatic faunal abundance, overall species and more specific mayfly-stonefly-caddis (EPT) richness through the Bourne Rivulet as shown in part in the previous graphs and the figure below.
Organic enrichment (Saprobicity) and aquatic ecological condition through the Bourne Rivulet -
Spring 2013
0
5
10
15
20
25
30
35
40
Bourne Rivulet
Upstream over-
pumping at
Stoke
Bourne Rivulet
Upstream
Vitacress @
Derrydown
Farm
Bourne Rivulet
(West) 200m
d/s SMB Cress
Farm
Bourne Rivulet
(East) 200m d/s
SMB Cress
Farm
Site 5Bourne
Rivulet The
Island 1100m
d/s SMB Cress
Farm
Bourne Rivulet
Ironbridge
1800m d/s SMB
Cress Farm
Sample Site Flow
Aq
uati
c f
au
nal ab
un
dan
ce x
10
2 a
nd
no
. o
f
sp
ecie
s (
bio
div
ers
ity)
0
2
4
6
8
10
12
14
16
18
20
EP
T(S
) an
d S
ap
rob
ic in
dex
Abundance 3 min-1 kick-sweep
R (species richness)
EPT(S)
Saprobic index
Similarly, the spatial pattern for sediment impacts in 2013 identified sediment (~PSI) incursion from a source between Stoke and Derrydown Farm, with further marked sediment augmentation via the Bourne East Rivulet, associated with a signature of reduced aquatic faunal abundance, overall species and more specific mayfly-stonefly-caddis (EPT) richness through the Bourne Rivulet as shown in the previous graphs and the figure overleaf.
Consultancy
Dr. Nick Everall MIFM C Env ���� rnaquaconsult@aol.com ℡℡℡℡ 01246 239344 22
Siltation (PSI) and aquatic ecological condition through the Bourne Rivulet - Spring 2013
0
5
10
15
20
25
30
35
40
Bourne Rivulet
Upstream over-
pumping at
Stoke
Bourne Rivulet
Upstream
Vitacress @
Derrydown
Farm
Bourne Rivulet
(West) 200m
d/s SMB Cress
Farm
Bourne Rivulet
(East) 200m d/s
SMB Cress
Farm
Site 5Bourne
Rivulet The
Island 1100m
d/s SMB Cress
Farm
Bourne Rivulet
Ironbridge
1800m d/s SMB
Cress Farm
Sample Site Flow
Aq
uati
c f
au
nal ab
un
dan
ce x
102 a
nd
no
. o
f sp
ecie
s
(bio
div
ers
ity)
0
10
20
30
40
50
60
70
80
90
100
EP
T(S
) an
d P
SI
Abundance 3 min-1 kick-sweep
R (species richness)
EPT(S)
PSI(S)
The graph below shows a synopsis of the general aquatic faunal condition (R and abundance) with the more specific riverfly (No. of EPT) and up-winged fly or mayfly (No. of UWF) plus associated patterns of pressure sensitive stresses in the watercourse e.g. siltation (PSI) and flow velocity (LIFE) fingerprints in the invertebrate communities of the upper West Rivulet in 2005 and 2013.
R (
specie
s r
ichness)
EP
T (
no. m
ay-c
addis
-sto
nefly)
UW
F (
no. m
ayflie
s)
*PS
I (s
ilt)
S (
org
anic
pollu
tion)
LIF
E (
flow
)
*TR
PI ([
P] enrichm
ent)
A (
faunal ab
undance
x 1
03 m
-2)
2005
2013
0
5
10
15
20
25
30
35
40
45
50
Biometric quality and stress
gradient ↑
Measure
Year (Spring)
Aquatic ecological condition and key watercourse stresses in the Bourne (West) Rivulet near St.
Mary Bourne 2005 and 2013
2005
2013
*Please note that both Percentage Sedimentation (PSI) and Total Reactive Phosphorous indices have been inverted because low percentage values traditionally represent high sediment and total reactive phosphorous signatures in the ecology but this was considered counter-intuitive to the reader. High percentage values now represent high biometric stress gradients in the graphs throughout this report unless stated otherwise.
The graph overleaf shows a synopsis of the general aquatic faunal condition (R and abundance) with the more specific riverfly (No. of EPT) and up-winged fly or mayfly (No. of UWF) plus associated patterns of pressure sensitive stresses in the
Consultancy
Dr. Nick Everall MIFM C Env ���� rnaquaconsult@aol.com ℡℡℡℡ 01246 239344 23
watercourse e.g. siltation (PSI) and flow velocity (LIFE) fingerprints in the invertebrate communities of the upper East Rivulet in 2005 and 2013.
R (
specie
s r
ichness)
EP
T (
no. m
ay-c
addis
-sto
nefly)
UW
F (
no. m
ayflie
s)
*PS
I (s
ilt)
S (
org
anic
pollu
tion)
LIF
E (
flow
)
*TR
PI ([
P] enrichm
ent)
A (
faunal ab
undance
x 1
03 m
-2)
2005
2013
0
10
20
30
40
50
60
70
Biometric quality and stress
gradient ↑
Measure
Year (Spring)
Aquatic ecological condition and key watercourse stresses in the Bourne (East) Rivulet near St.
Mary Bourne 2005 and 2013
2005
2013
*Please note that both Percentage Sedimentation (PSI) and Total Reactive Phosphorous indices have been inverted because low percentage values traditionally represent high sediment and total reactive phosphorous signatures in the ecology but this was considered counter-intuitive to the reader.
The key findings from these studies in the Bourne Rivulet were that, independent to flow velocity, as organic, sediment and nutrient [P] levels dissipated spatially in 2013 and temporally between 2005 and 2013 there was a marked increase in overall riverine invertebrate abundance and species richness which was under pinned by a rise in both general riverfly and specific up-winged fly richness. It should also be noted that now rare and Biodiversity Action Plan (BAP) riverfly species like the Southern Iron Blue (Baetis niger) and the Red Data Base (RDB) Scarce Purple Dun (Paraleptophlebia werneri) were only found at the upper survey sites in this study of the Bourne Rivulet where organic, sediment and nutrient signatures corresponded to clean reference watercourse conditions. 2.2.2 The River Test in Hampshire (1995-2013)
As yet there has been no hind cast analysis of historic family macroinvertebrate datasets on the River Test with the recently developed full suite of biometric tests for sediment, flow, nutrient and organic signatures of aquatic ecological condition but work is in progress to address this matter pending funding. Prior to 2013, the only comprehensive fully quantitative and species level analyses pertinent to riverfly population status in the River Test was undertaken by Dr. Cyril Bennett at Leckford upon Blue Winged Olive (Serratella ignita) populations (Bennett and Gilchrist, 2010) and the data is shown overleaf.
Consultancy
Dr. Nick Everall MIFM C Env ���� rnaquaconsult@aol.com ℡℡℡℡ 01246 239344 24
The decline in the Blue Winged Olive (Seratella ignita) on the River Test at Leckford which has been reproduced with kind permission by the author from Bennett and Gilchrist (2010).
Blue Winged Olive (Serratella ignita) abundances at Leckford in River Test
The nymph data from Bennett and Gilchrist (2010) suggested a decline in the population size of the Blue Winged Olive mayfly at Leckford in the River Test post-1995 but monitoring ceased in 2004 and there was sadly no more data to assess the longer-term trend at this study site. However, the author is aware that there has been some recent species level and quantitative invertebrate community surveying undertaken in the River Test at Leckford in 2013 but due process relating to a Ph D submission and associated publications must be respected before this information can be made available in the public domain. Thanks to the forward thinking of several independent riparian owners a spatial spread of appropriate species community and fully quantitative sampling commenced through parts of the River Test in 2013. Initial studies in 2013 showed that fully quantitative replicate Surber net sampling produced bio-quality (BMWP, ASPT, NTAXA, R, EPT …) and biometric (PSI, S, LIFE, TRPI …) site results for the River Test that were not significantly different from semi-quantitative 3 minute kick-sweep net sample findings. To provide robust quantification of results in numbers of invertebrates m-2 the quantitative species invertebrate community data has been used in the graph overleaf from the same season and day of sampling in 2013 (Everall, 2013f).
Consultancy
Dr. Nick Everall MIFM C Env ���� rnaquaconsult@aol.com ℡℡℡℡ 01246 239344 25
R (
sp
ecie
s r
ich
ne
ss)
UW
F (
no
. m
ayflie
s)
LIF
E (
flo
w)
*TR
PI ([
P]
en
rich
me
nt)
1st d/sLongparish
Ist main carrier u/s Stockbridge
d/s Stockbridge
0
10
20
30
40
50
60
Biometric quality and stress
gradient ↑
Measure
Site & Flow ↑
Aquatic ecological condition and key watercourse stresses in the River Test in Hampshire
from Long Parish → Stockbridge in Autumn 2013
1st d/sLongparish
2nd d/s Longparish
Ist main carrier u/s Stockbridge
2nd main carrier u/s Stockbridge
d/s Stockbridge
*Please note that both Percentage Sedimentation (PSI) and Total Reactive Phosphorous indices have been inverted because low percentage values traditionally represent high sediment and total reactive phosphorous signatures in the ecology but this was considered counter-intuitive to the reader.
As siltation (PSI), organic (S) and nutrient TRP (TRPI) enrichment increased with decreasing flow velocity from Longparish down to below Stockbridge in the River Test in the Autumn of 2013 there was an associated loss of general riverfly → up-winged fly species richness and faunal abundance. The details of these individual stress impacts are highlighted in the graphs below and overleaf.
Species richness of riverflies and up-winged flies with mild organic enrichment through the River
Test from Long Parish to Stockbridge → Autumn 2013
0
5
10
15
20
25
30
1st d/sLongparish 2nd d/s Longparish Ist main carrier u/s
Stockbridge
2nd main carrier u/s
Stockbridge
d/s Stockbridge
Site and Flow →
No
. ri
verf
ly s
pecie
s m
-2 (±
95%
C.L
.)
0
0.5
1
1.5
2
2.5
Sap
rob
ic in
dex (
org
an
ic e
nri
ch
men
t)
EPT (no. may-caddis-stonefly)
UWF (no. mayflies)
S (organic pollution)
Consultancy
Dr. Nick Everall MIFM C Env ���� rnaquaconsult@aol.com ℡℡℡℡ 01246 239344 26
There was a generally statistically significant (P<0.05) reduction in riverfly and up-winged fly species richness from Longparish → Stockbridge which appeared to inversely mirror the trend in rising organic enrichment through these reaches of the river.
Species richness of riverflies and up-winged flies with flow velocity through the River Test from
Long Parish to Stockbridge → Autumn 2013
0
5
10
15
20
25
30
1st d/sLongparish 2nd d/s Longparish Ist main carrier u/s
Stockbridge
2nd main carrier u/s
Stockbridge
d/s Stockbridge
Site and Flow →
No
. ri
verf
ly s
pec
ies m
-2 (
± 9
5%
C.L
.)
6.8
7
7.2
7.4
7.6
7.8
8
8.2
8.4
8.6
LIF
E (
Flo
w v
elo
cit
y)
EPT (no. may-caddis-stonefly)
UWF (no. mayflies)
LIFE (flow)
There was a generally statistically significant (P<0.05) reduction in riverfly and up-winged fly species richness from Longparish → Stockbridge which appeared to inversely mirror the trend in decreasing flow velocities through these reaches of the river.
Species richness of riverflies and up-winged flies with siltation through the River Test from Long
Parish to Stockbridge → Autumn 2013
0
5
10
15
20
25
30
1st d/sLongparish 2nd d/s Longparish Ist main carrier u/s
Stockbridge
2nd main carrier u/s
Stockbridge
d/s Stockbridge
Site and Flow →
No
. ri
verf
ly s
pecie
s m
-2 (±
95%
C.L
.)
0
10
20
30
40
50
60
70
80
90
100
Silta
tio
n (
PS
I)
EPT (no. may-caddis-stonefly)
UWF (no. mayflies)
*PSI (silt)
There was a generally statistically significant (P<0.05) reduction in riverfly and up-winged fly species richness from Longparish → Stockbridge which appeared to
Consultancy
Dr. Nick Everall MIFM C Env ���� rnaquaconsult@aol.com ℡℡℡℡ 01246 239344 27
inversely mirror the trend in increasing sedimentation through these reaches of the river.
Species richness of riverflies and up-winged flies with nutrient (TRP) enrichment through the River
Test from Long Parish to Stockbridge → Autumn 2013
0
5
10
15
20
25
30
1st d/sLongparish 2nd d/s Longparish Ist main carrier u/s
Stockbridge
2nd main carrier u/s
Stockbridge
d/s Stockbridge
Site and Flow →
No
. ri
verf
ly s
pecie
s m
-2 (±
95%
C.L
.)
0
10
20
30
40
50
60
70
80
90
100
TR
P e
nri
ch
men
t (T
RP
I)
EPT (no. may-caddis-stonefly)
UWF (no. mayflies)
*TRPI ([P] enrichment)
There was a generally statistically significant (P<0.05) reduction in riverfly and up-winged fly species richness from Longparish → Stockbridge which appeared to inversely mirror the trend in increasing nutrient (TRP) enrichment through these reaches of the river. The key findings were that, unlike some of the finding from other watercourse case studies in this report the evident stress signatures of organic, sediment and nutrient impacts upon the ecology in the River Test in 2013 were potentially exacerbated by decreasing flow velocity with distance downstream which would, in all probability, associate with decreased flow (volume) dilution of point-source discharges and more diffuse pollution through this river corridor. It should also be noted that now rare and Biodiversity Action Plan (BAP) riverfly species like the Southern Iron Blue (Baetis
niger) and the Red Data Base (RDB) Scarce Purple Dun (Paraleptophlebia werneri) were only found at the upper survey sites in this study of the River Test where organic, sediment and nutrient signatures corresponded to clean reference watercourse conditions. 2.2.3 The River Itchen in Hampshire (1995-2013)
As yet there has been no hind cast analysis of historic family macroinvertebrate datasets on the River Test with the recently developed full suite of biometric tests for sediment, flow, nutrient and organic signatures of aquatic ecological condition but work is in planned with respect to this matter in 2014. At present, in the absence of any funding for hind cast family invertebrate analysis and collation of fully quantitative species level community invertebrate data we have taken a look at some of the environmental biometric stresses evident from EA GQA data in the area of the Upper River Itchen around Alresford. The biological ‘snap shot’ of pollutant stresses in the Upper River Itchen around Alresford in 2010-2013 was undertaken to compliment some current 2013 chemical nutrient investigations of
Consultancy
Dr. Nick Everall MIFM C Env ���� rnaquaconsult@aol.com ℡℡℡℡ 01246 239344 28
phosphorous levels being undertaken by The Salmon & Trout Association in collaboration with Dr. P. Shaw at Southampton University. The graph below showed that in this reach of the Upper River Itchen the aquatic faunal signatures of nutrient (TRPI) impact declined downstream from Alreford to Itchen Stoke as the ‘summer’ (July-August 2013) chemical total reactive phosphorous levels dropped in the river and this was set against a backdrop of a moderate but declining sediment moulding of the watercourse ecology through this reach of the watercourse.
Siltation (PSI) and nutrient (TRP & TRPI) signatures in Upper → River Itchen from Alresford Itchen
Stoke 2010-2013
0
10
20
30
40
50
60
70
80
90
100
Alresfor
d
21.3
.13
Arle
1.7.
11
21.3
.13
8.4.
10
28.9
.10
24.3
.11
22.9
.11
26.3
.12
10.1
0.12
21.3
.13
d/s Can
dove
r Bro
ok
20.4
.10
28.9
.10
18.1
1.10
24.3
.11
22.9
.11
20.1
0.11
26.3
.12
21.3
.13
Itche
n Sto
ke
8.4.
10
28.9
.10
26.3
.12
14.9
.12
3.5.
13
Site, sample date and flow →
PS
I (s
ilta
tio
n)
an
d T
RP
I (T
RP
) %
0
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
0.18
Mean
To
tal R
eacti
ve P
ho
sp
ho
rou
s (
TR
P)
in m
g/l
Ju
ly-S
ep
tem
ber
2013 (
95%
C.L
.)
TRPI
PSI
[TRP]
*Please note that both Percentage Sedimentation (PSI) and Total Reactive Phosphorous indices have been inverted because low percentage values traditionally represent high sediment and total reactive phosphorous signatures in the ecology but this was considered counter-intuitive to the reader.
Of interest to the River Itchen and the wider debate about [P] chemical standards for watercourses was the fact that as for PSI, TRPI values ≥ 20% are considered to indicate invertebrate macroinvertebrate communities with more TRP indicator species than would be expected from a clean water ‘reference’ community. In the Upper River Itchen this associated with chemical TRP levels ≥ 0.04 mg TRP/l. At present, without the accompanying resolution of species level macroinvertebrate community analysis it was not possible at present to determine what specific impacts this sediment and phosphorous moulding of the fauna was having on e.g. the receiving riverfly aspects of ecological condition in the River Itchen. 2.2.4 Historic perspectives and wider pressures for riverfly populations
There is an inherent contextual problem for all 21st Century biologists or water catchment managers trying to manage the ecological state of our rivers and that is that ‘reference’ sites are becoming increasingly rare because human modification of river systems is so pervasive that sites with a representative suite of minimally disturbed watercourse conditions have become increasingly scarce (Everall and Farmer, 2012). This is highlighted by e.g. the current state of siltation across rivers in England and
Tentative threshold
TRPI for ecological
moulding above
reference condition
Consultancy
Dr. Nick Everall MIFM C Env ���� rnaquaconsult@aol.com ℡℡℡℡ 01246 239344 29
Wales as highlighted in the 2012 map below where the yellow, red and black dots represent moderate, poor and bad levels of watercourse sedimentation using the Percentage Siltation Index (Extence et. al., 2010 and Extence et. al., 2011).
Graph reproduced with the kind permission of Ian Humpheryes at the Environment Agency
The author and colleagues at Staffordshire University are currently working on a matching map for the biological signature of total reactive phosphorous (TRP) across UK watercourses using the new macroinvertebrate based TRP model but this is a voluntary exercise and effort limited at present by the lack of any funding. While we still may soon be able to produce a fairly comprehensive ‘current state of play’ for environmental stresses that may prove to be associated with riverfly demise, where that occurs, the detailed historic (pre-1970’s) macroinvertebrate community data required to make longer-term comparisons remains fairly elusive and compounded by later changes in the level of taxonomic analysis used on biological samples. Also, many of the watercourses where there is now evidence or riverfly and up-winged fly demise were not historically extensively biologically surveyed because many were regarded as clean, if not pristine and were not deemed to warrant investigational resources. However, if it exists, then any such distant historic biological data would be contextually very informative when analysed and referenced against environmental stress patterns like that shown e.g. for chemical nitrogen and phosphorous nutrient enrichment in the lower River Avon overleaf.
Consultancy
Dr. Nick Everall MIFM C Env ���� rnaquaconsult@aol.com ℡℡℡℡ 01246 239344 30
Reproduced by the kind permission of Chris Mainstone at Natural England from Mainstone
(2010)
In conclusion, it should be remembered that this investigation was driven from evidence based case studies and long-term field observations of suspected riverfly demise. What was interesting was that a number of once regarded or measured ‘pristine’ UK rivers of current ‘good ecological status’ were showing evidence of riverfly demise in recent decades in association with relatively mild increases in sediment, nutrient, organic and occasionally reduced flow regimes. Conversely, a number of northern limestone rivers historically listed as of ‘good ecological status’ that received species level biomonitoring targeting of CSF investment went on to show significant improvement in riverfly population status and were clearly not at the optimum that previous river classification had implied. A number of historically degraded UK rivers have also shown massive improvements in ecological quality e.g. the River Trent and the River Erewash following multi-million pound investments in tackling pollutant inputs as shown for the River Trent overleaf.
Consultancy
Dr. Nick Everall MIFM C Env ���� rnaquaconsult@aol.com ℡℡℡℡ 01246 239344 31
So the reader should not go away with the impression that all rivers in the UK are experiencing ecological and riverfly demise because it is a mixed bag of results. However, fewer than 40% of surface waters were in broad brush ‘good ecological status’ in 2009, at an early stage of the Water Framework Directive and river basin management plans with only 5% more expected to reach good ecological status by 2015. This report highlights that a number of ‘good ecological status’ were not or are not as good as they could be and hide more subtle ecological impacts because of the current resolution of analysis employed for Regulatory monitoring. Furthermore, there was a common thread of marked and often combined sediment, nutrient and organic signatures in the aquatic ecology of rivers experiencing loss of riverfly species richness and abundance but these factors were not the only stresses responsible for all cases of riverfly demise. It is not unusual to encounter a range of stresses impacting UK watercourses and only by tackling all of them can the ecological integrity of river habitats be secured (Mainstone and Clarke 2008). Although not burning in these studies, the wider picture needs to consider that over abstraction will both compound the impacts of the key identified stresses associated with riverfly demise and flow or lack of flow will influence the invertebrate community composition in itself. Similarly, other pollutants can occasionally dramatically decimate riverfly populations like the pesticide chlorpyrifos incursions into the South Wey in 2002-2003 (Everall, 2003) and the River Kennett in 2013 (Everall, 2013g) but these are usually readily differentiated from other stresses. There is also growing evidence that river water temperature is changing in response to climate change (Kaushal et al., 2010; van Vliet et al., 2011; Lough & Hobday et al., 2011; Isaak et al., 2012). Aquatic organisms respond to changing thermal conditions in complex ways (Ward & Stanford, 1982). Given the dependence of phenology on heat accumulation, emergence of insects is particularly susceptible to changing temperature and can have adverse effects on freshwater insects populations (Harper & Peckarsky, 2006; Durance and Ormerod, 2007; Thackeray et al., 2010 and Everall, 2013h). Such additional thermal pressures on the immediate horizon only make it more important to currently identify and protect sensitive riverfly rich watercourses
Consultancy
Dr. Nick Everall MIFM C Env ���� rnaquaconsult@aol.com ℡℡℡℡ 01246 239344 32
from other pressures, such as agricultural pollution, suspended sediment loads or hydrological changes. So, while it is important to add to any growing evidence base of a documented quantum loss in some riverfly populations on any impacted rivers, there is a greater need to understand the root causes of these declines and thus to provide some solutions. The species level invertebrate community studies highlighted in this report have started to provide the necessary evidence on riverfly populations for impacted and un-impacted watercourses in the UK but there is much more work required to get a wider local and regional perspective upon this matter. The more riparian owners prepared to fund benchmarking their own waters using these techniques and the recent Environment Agency move towards collecting more species resolution biometric data will enable stress pinch points of riverfly demise to be more readily pin pointed and for targeted remedial measures to be applied in watercourses.
Acknowledgements
The author would like to thank Dr. Chris Mainstone at Natural England for helping to progress species level condition assessment on UK rivers. Similar thanks are also due to Dr. Chris Extence, Richard Chadd, Juliette Hall, Phil Smith, Dave Ottewell and Shirley Medgett at the Environment Agency for forward thinking in both development of biometric fingerprinting and application to field studies. Thanks to my colleagues Dr’s. Martin Paisley, Bill Walley and Dave Trigg at Staffs University in the development of the macroinvertebrate TRPI model to date.
References
ADAS (2009). Linking agricultural land use and practices with a high risk of phosphorus loss to chemical and ecological impacts in rivers (the PARIS project). Research Project Final Report (SID5) to Defra. Defra, London. Alabaster, J.S. and Lloyd, R. (1980). Water Quality Criteria for Freshwater Fish. London, FAO and Butterworths. (Second edn, 1982). Arscott, D.B., Jackson, J.K. and Kratzer, E.B. (2006). Role of rarity and taxonomic resolution in a regional and spatial analysis of stream macroinvertebrates. Journal of the North American Benthological
Society, 25, 977–997. Armitage, P.D., Moss, D., Wright, J.F. and Furse, M.T. (1983). The performance of a new biological quality score system based upon macro-invertebrates from a wide range of unpolluted running water sites, Water Research, 17, 333-347. Bennett, C and Gilchrist, W. (2010). Chapter 22. Riverflies In: Silent Summer. The State of Wildlife in Britain and Ireland. Ed. N. Maclean. Cambridge University Press, Cambridge, 765pp. Calow, P. & G. Petts: The Rivers Handbook I: Hydrological and Ecological Principles; Wiley and Sons, 1993.
Consultancy
Dr. Nick Everall MIFM C Env ���� rnaquaconsult@aol.com ℡℡℡℡ 01246 239344 33
Chadd R and Extence C. (2004). The conservation of freshwater macroinvertebrate populations: a community-based classification scheme. Aquatic Conservation: Marine
and Freshwater Ecosystems, 14, 597-624. Clements, W.H. and Newman, M.C. (2002). Community Ecotoxicology. Hierarchical Ecotoxicology Series. John Wiley and Sons Ltd, Hoboken, USA. Clews, E. and Ormerod, S.J. (2009). Improving bio-diagnostic monitoring using simple combinations of standard biotic indices. River Research and Applications, 25, 348-261. doi: 10.1002/rra.1166. Dineen, G., Harrison, S.S.C. and Giller, P.S. (2007). Diet partitioning in sympatric Atlantic salmon and brown trout in streams with contrasting riparian vegetation. Journal of Fish Biology, 71, 17-38. Dunbar, M.J,. Pederson, M.L., Cadman, D., Extence, C., Waddingham, J., Chadd, R. and Larsen, S.E. 2010a. River discharge and local scale physical habitat influence macroinvertebrate LIFE score. Freshwater Biology, 55: 226–242.
Dunbar, M.J., Warren, M., Extence, C.A., Baker, L., Cadman, D., Mould, D., Hall, J. and Chadd, R. 2010b. Interaction between macroinvertebrates, discharge and physical habitat in upland rivers. Aquatic Conservation: Marine Freshwater Ecosystems. DOI: 10.1002/aqc.1089 Dunne, T., Mertes, L.A.K,, Meade, R.H., Richey, J.E. and Forsberg, B.R. 1998. Exchanges of sediment between the flood plain and channel of the Amazon River in Brazil. Geology Society American Bulletin, 110, 450–467. Durance I, Ormerod SJ. 2007. Climate change effects on upland stream macroinvertebrates over a 25-year period. Global Change Biology 13, 942–957. Durance, I. and Ormerod, S.J. (2009). Trends in water quality and discharge confound long-term warming effects on river macroinvertebrates. Freshwater Biology, 54, 388-405. doi:10.1111/j.1365-2427.2008.02112.x Environment Agency (1999). Dove Local Environment Agency Plan (LEAP). Environmental Overview, August 1999. Environment Agency, Rio House, Bristol, 103pp. Environment Agency (2009a) Freshwater Macro-invertebrate sampling in Rivers. Operational Instruction 018_08. Environment Agency. Environment Agency (2009b) Freshwater Macro-invertebrate Analysis of Riverine Samples. Operational Instruction 024_08. Environment Agency.
Everall, N.C. et al (1991a) Tracing of haematotoxic agents in water with the aid of captive fish: a study with captive adult Atlantic salmon (Salmo salar) in the River Don. Diseases Aquatic Organisms , 10, 75-85.
Consultancy
Dr. Nick Everall MIFM C Env ���� rnaquaconsult@aol.com ℡℡℡℡ 01246 239344 34
Everall, N.C. et al. (1991b). Effluent causes of the pigmented salmon syndrome in wild adult Atlantic salmon ( Salmo salar ) from the River Don. Diseases Aquatic
Organisms, 12, 46-52. Everall, N.C. (2003). A preliminary expert witness report for the A.C.A. on the South Wey pollution events of 2002 and 2003. An Expert Witness report for the Anglers Conservation Association, Leominster, 33pp. Everall, N.C. (2005). The biological fingerprint for nutrient enrichment in the River Hamps and the River Manifold. A Technical Report for the Environment Agency at Lichfield. Aquascience, 13pp. Everall, N.C. (2010). The aquatic ecological status of the rivers of the Upper Dove Catchment in 2009. Natural England Research Reports, Number 046. Natural England, Sheffield. Everall, N.C. and Farmer, A. (2012). Evaluation of macroinvertebrate indicators and associated thresholds for favourable conditions. Natural England Research Reports,
Number 065. Natural England, Sheffield. Everall, N.C. (2013a). The Mayfly Climate Phenology Project, The Annual Journal of the Wild Trout Trust, Salmo Trutta, 16, 46-47. Everall, N.C. (2013b). Aquatic environmental assessment of the River Wye through SSSI reaches 70 & 71 in May and September 2013. Aquascience Consultancy report for Natural England, 140pp. Everall, N.C. (2013c). Aquatic environmental assessment of the Bourne Rivulet in Hampshire from 1989-2013. Aquascience Consultancy report for the Bourne Bright Waters Trust, 22pp. Everall, N.C. (2013d). An Aquatic Ecological Appraisal of Catchment Sensitive Farming in the Upper Dove Catchment 2009-2013. Aquascience Consultancy report for Environment Agency. EA, Bristol, 43pp. Everall, N.C. (2013e). An aquatic environmental assessment of the Bourne Rivulet 1989-2013. Aquascience Consultancy report for Bourne Bright Waters Trust, 30pp. Everall, N.C. (2013f). Confidential reports for several riparian owners in the River Test in 2013. Available with discretion and upon request. Everall, N.C. (2013g). An interim aquatic environmental assessment of the River Kennett in the upper reach of the Savernake Fly Fishers waters in July 2013. Aquascience Consultancy report for Fish Legal, 22pp. Extence, C. A., Balbi, D.M. and Chadd, R.P. (1999). River Flow Indexing using British benthic macroinvertebrates: A framework for setting hydro ecological objectives. Regulated Rivers Research and Management. 15, 543-574.
Consultancy
Dr. Nick Everall MIFM C Env ���� rnaquaconsult@aol.com ℡℡℡℡ 01246 239344 35
Extence, C.A, Chadd, R.P, England, J., Dunbar, M.J., Taylor, E.D. and Everall, N.C. (2010). The assessment of fine sediment accumulation in rivers using macroinvertebrate community response. BHS Third International Symposium, Managing Consequences of a Changing Global Environment, Newcastle, 2010. Extence, C.A., Chadd, R.P., England, J., Dunbar, M.J., Wood, P.J. and Taylor, E.D. (2011). The Assessment of Fine Sediment Accumulation in Rivers Using Macro-invertebrate Community Response. River Research and Applications, 30pp. Frake, A. and Hayes, P. (2001). Report on the millennium chalk streams fly trends study. Environment Agency publications. ISBN 1 85 705759 7 Friberg, N., Skriver, J., Larsen, S.E., Pedreson, M.L. and Buffagni, A. (2010). Stream macroinvertebrate occurrence along gradients of organic pollution and eutrophication. Freshwater Biology, 55, 1405-1419. Göransson G, Hultén C, Johansson Å, Andersson-Sköld Y, Lind, B. 2009. Climate change enhanced risk for mass failure of sediment into rivers - how do we manage such events? 6th Sediment Conference. Hamberg 7-9 October 2009. Harding, J.S., Young, R.G., Hayes, J.W., Shearer, K.A. and Stark, J.D. 1999. Changes in agricultural intensity and river health along a river continuum. Freshwater Biology,
42, 345–357. Harper, M.P. & Perckarsky, B.L. (2006) Emergence cues of a mayfly in a high-altitude stream ecosystem: Potential response to climate change. Ecological
Applications 16, 612–621. Hauer, F. R. and Lamberti, G. A. (1996). Methods in Stream Ecology, Academic Press, 1996. Hellawell, J.M. (1986). Biological indicators of freshwater pollution and environmental management. Pollution Monitoring Series. London, Elsevier Applied Science, 546pp. Hering, D., Schmidt-Kloiber, A., Murphy, J., Lucke, S., Zamora-Munoz, C., Lopez-Rodriguez,M.J., Huber, T. and Graf, W. (2009). Potential impact of climate change on aquatic insects: a sensitivity analysis for the European caddis flies (Trichoptera) based on distribution patterns and ecological preferences. Aquatic Sciences, 71, 3-14. H.M.S.O. (1985). Methods of Biological Sampling Handnet Sampling of Aquatic Benthic Macroinvertebrates. Methods for the Examination of Waters and Associated Materials. London, 8 pp. Hooda, P.S., Edwards, A.C., Anderson, H.A. and Miller, A. (2000). A review of water quality concerns in livestock farming areas. The Science of the Total Environment, 250, 143-167.
Consultancy
Dr. Nick Everall MIFM C Env ���� rnaquaconsult@aol.com ℡℡℡℡ 01246 239344 36
Imhof, J.G., Fitzgibbon, J. and Annable, W.K. 1996. A hierarchical evaluation system for characterizing watershed ecosystems for fish habitat. Canadian Journal Fisheries Aquatic Sciences, 53, 312–326. Isaak, D.J., Wollrab, S. Horan, D. & Changler, G. (2012) Climate change effects on stream and river temperatures across the northwest U.S. from 1980–2009 and implications for salmonid fishes. Climate Change 113, 499–524.
ISO 7828: 1985 (BS EN 27828) (1994). Water Quality - Methods of biological sampling - Guidance on handnet sampling of aquatic benthic macro-invertebrates.
Kaushal, S.S., Likens, G.E., Jaworski, N.A., Pace, M.L., Sides, A.M., Seekell, D., Belt, K.T., Secor, D.H. & Wingate, R.L. (2010) Rising stream and river temperatures in the United States. Frontiers in Ecology and the Environment 8, 461–466.
Lough, J.M. & Hobday, A.J. (2011) Observed climate change in Australian marine and freshwater environments. Marine and Freshwater Research 62, 984–999. Mainstone, C.P. and Clarke, S.J. (2008). Managing multiple stressors on sites with special protection for freshwater wildlife - the concept of Limits of Liability. Freshwater Reviews, 1, 175-187. Mainstone, C.P. (2010a). An evidence base for setting nutrient targets to protect river habitat. Natural England Research Reports, Number 034. Natural England, Sheffield. Mainstone, C. and Holmes, P. (2010b). Embedding a strategic approach to river restoration in operational management processes: experiences in England. Aquatic Conservation: Marine and Freshwater Ecosystems, 23, S82–95. Mainstone, C.P. and Hatton-Ellis, T. (2011) The rationale for undertaking condition assessment of designated river habitat. Paper written on behalf of the Freshwater Lead Coordination Network. Mainstone, C.P. (2012) The use of detailed macroinvertebrate assessment in river SSSI/SAC condition assessment. Paper written on behalf of the UK Common Standards Monitoring group on SSSI/SAC river habitat.
Monk, W.A, Wood, P.J., Hannah, D.M., Extence, C.A., Chadd, R.P. and Dunbar, M.J. (2011). How does macroinvertebrate taxonomic resolution influence ecohydrological relationships in riverine ecosystems. Ecohydrology, published online in Wiley Online Library. DOI: 10.1002/eco.192 Nuttall, P.M. 1972. The effects of sand deposition upon the macroinvertebrate fauna of the River Camel, Cornwall. Freshwater Biology, 2, 181–186. Paisley, M.F., Walley, W.J., Nikhade, J. and Dils, R. (2003). Identification of the key biological indicators of nutrient enrichment in rivers for use in predictive/diagnostic
Consultancy
Dr. Nick Everall MIFM C Env ���� rnaquaconsult@aol.com ℡℡℡℡ 01246 239344 37
models. Proceeding of the 7th International Specialised IWA Conference on Diffuse Pollution and Basin Management, Dublin, Ireland. Paisley, M.F., Walley, W.J. and Trigg, D.J. (2011). Identification of macro-invertebrate taxa as indicators of nutrient enrichment in rivers. Ecological Informatics, 6, 399–406. doi:10.1016/j.ecoinf.2011.09.002. Pantle, R. and Buck, H. (1955). Die biologische Uberwachung der Gewasser und die Darstellung der Ergebnisse. Gas-u Wasserfach, 96, 604. Rapport, D.J., Reiger, H.A. and Hutchinson, T.C. (1985). Ecosystem behaviour under stress. Am. Nature, 125, 617-640. Sandin, L. and Hering, D. (2004). Comparing macroinvertebrate indices to detect organic pollution across Europe: a contribution to the EC Water Framework Directive intercalibration. Hydrobiologia, 516, 1-3, 55-68. Schriever, C,, Hansler-Ball, M., Holmes, C., Maund, S. and Liess, M. 2007. Agricultural intensity and landscape structure: influences on the macroinvertebrate assemblages of small streams in Northern Germany. Environmental Toxicology Chemistry, 26, 346–357. Smith, H. and Wood, P. J. (2002). Flow permanence and macroinvertebrate community variability in limestone spring systems. Hydrobiologia 487: 45-58. Smith, H., Wood P.J. and Gunn, J. (2003). The influence of habitat structure and flow permanence on invertebrate communities in karst spring systems. Hydrobiologia 510: 53-66. Soulsby, P.G. (1985). Report on a survey of the River Bourne. Downstream from St. Mary Bourne Cress Farm, on the 2nd May 1985. Southern Water Authority, Winchester, 3pp. Spänhoff, B. and Arle, J. (2007). Setting attainable goals of stream habitat restoration from a macroinvertebrate view. Restoration Ecology, 15, 317–20. Storey, A.W, Edward, DW.D. and Gazey, P. (1991). Surber and kick sampling: a comparison for the assessment of macroinvertebrate community structure in streams of south-western Australia. Hydrobiologia, 211, 111-121. Thackeray, S.J., Sparks, T.H., Frederiksen, M., Burthes, S., Bacon, P.J., Bell, J.R., Botham, M.S., Brereton, T.M., Bright, P.W., Carvalho, L., Clutton-Brock, T., Dawsons, A., Edwards, M., Elliott, M., Harrington, R., Johns, D., Jones, I.D., Jones, J.T., Leech, D.I., Roy, D.B., Scott, W.A., Smith, M., Smithers, R.I., Winfield, I.J. & Wanless, S. (2010) Trophic level asynchrony in rates of phonological change for marine, freshwater and terrestrial environments. Global Change Biology 16, 3304–3313.
Consultancy
Dr. Nick Everall MIFM C Env ���� rnaquaconsult@aol.com ℡℡℡℡ 01246 239344 38
Townsend, C.R., Uhlmann, S.S. and Matthaei, C.D. (2008). Individual and combined responses of stream ecosystems to multiple stressors. Journal of Applied Ecology, 45, 6, 1810-1819. van Vliet, M, T.H., Ludwig, F., Zwolsman, J.J.G., Weedon, G.P. & Kabat, P. (2011) Global river temperatures and sensitivity to atmospheric warming and changes in river flow. Water Resources Research 47, 10.1029/2010WR009198. Ward, J.V. & Stanford, J.A. (1982) Thermal responses in the evolutionary ecology of aquatic insects. Annual Review of Entomology 27, 97–117. Wood, P.J., Armitage, P.D., Cannan, C.E. and Petts, G.E. (1999). In stream mesohabitat biodiversity in three groundwater streams under base-flow conditions. Aquatic Conservation: Marine and Freshwater Ecosystems, 9, 265-278. Wood, P.J., Gunn, J., Smith, H. and Abas-Kutty, A.(2005). Flow permanence and macroinvertebrate community diversity within groundwater dominated headwater streams and springs. Hydrobiologia 545: 55–64. Woodiwiss, F.S. (1964). The biological system of stream classification used by the Trent River Board, Chemy. Indust., 11, 443-447. Wright, J.F., J H Blackburn, J.H., Gunn, R.J., Symes, K.L. & Bowker, J. (1996). Scoping Study on the Ephemeroptera of Southern Chalk Streams. Institute Freshwater Ecology, Wareham, 48pp.
Wright, J.F., Sutcliffe, D.W. and Furse, M.T. (2000). Assessing the Biological Quality of Fresh Waters. RIVPACS and Other Techniques. Freshwater Biological Association, Windermere. Zelinka, M. and Marven, P. (1966). Bemerkung zu neuen Methoden der saprobiologischen Wasserbeurteilung. Verh int. Verein. Theor. Angew. Limnol, 16, 817-822. Appendices
Details of biometric testing used on the species macroinvertebrate community data across the various river case studies highlighted in this report.
Consultancy
Dr. Nick Everall MIFM C Env ���� rnaquaconsult@aol.com ℡℡℡℡ 01246 239344 39
Appendix 1 - Details of biometric testing used on the species macroinvertebrate
community data across the various river case studies highlighted in this report.
A number of pressure-sensitive biometrics are now available to determine fingerprints for siltation (Proportion of Sediment Sensitive Invertebrates or PSI), flow velocity conditions (Lotic Invertebrate Flow Evaluation or LIFE), organic enrichment (Saprobic index) and phosphate enrichment (Total Reactive Phosphorous Index or TRPI) from family and species level sample macroinvertebrate community data. These pressure-sensitive biometric tests were applied to both, where available, the historic EA GQA and the current 2013 macroinvertebrate sample data for all of the survey sites in the Bourne Rivulet catchment. Siltation from Proportion of Sediment-sensitive Invertebrates or PSI Physical assessment methods have traditionally been used to quantify riverine sedimentation, but Extence et. al. (2010) have proposed an alternative approach, the use of a sediment-sensitive macro-invertebrate metric, PSI (Proportion of Sediment-sensitive Invertebrates) which can act as a proxy to describe temporal and spatial impacts. Such techniques have also been used successfully at a large catchment scale to assess the spatial and temporal patterns of siltation in a watershed (Extence et. al., 2010, Everall, 2010 and Extence et. al., 2011). The PSI score describes the percentage of sediment-sensitive taxa (Table 1 overleaf) present in a sample and the metric is calculated using the matrix shown in Table 2 overleaf and then applying the following formula:
ε Sediment Scores for Sensitivity Groups A & B PSI (Ψ) = X 100
ε Sediment Scores for all Sensitivity Groups A, B, C & D
Table 1 Group Silt Tolerance Definition
A Taxa highly sensitive to sedimentation B Taxa moderately sensitive to sedimentation C Taxa moderately insensitive to sedimentation D Taxa highly insensitive to sedimentation E Taxa indifferent to sedimentation or excluded from the method for other
reasons.
Consultancy
Dr. Nick Everall MIFM C Env ���� rnaquaconsult@aol.com ℡℡℡℡ 01246 239344 40
Table 2 Group Sediment Sensitivity Log Abundance. Rating (SSR) 1-9 10-99 100-999 1000+ A Highly Sensitive 2 3 4 5
B Moderately Sensitive 1 2 3 4 C Moderately
Insensitive 1 2 3 4
D Highly Insensitive 2 3 4 5 E Excluded - - - -
From the literature review in Extence et. al. (2010), appropriate abundance and affinity weightings have been incorporated into Table 2 to give the final PSI metric better definition. PSI scores range from 0 (entirely silted river bed) to 100 (entirely silt-free river bed). Extence et. al. (2010) suggested that when applied to species and family data respectively, the terms PSI (S) and PSI (F) are used. A provisional interpretation scheme for the data is shown in Table 3 below (Extence et. al., 2010). Table 3 PSI River Bed Condition
81 -100 Naturally sedimented/Unsedimented 61 - 80 Slightly sedimented 41 - 60 Moderately sedimented 21 - 40 Sedimented 0 - 20 Heavily sedimented
In the current study of the Bourne Rivulet catchment the macroinvertebrate results for siltation expressed as PSI are in fact PSI(S) as there was sufficient resolution at species level across the biological data sets (Appendix 2) to facilitate PSI(S) analysis. For EA GQA dataset evaluations this was not the case and here the macroinvertebrate results for siltation expressed as PSI are in fact PSI(F). Flow velocity conditions from Lotic Invertebrate Flow Evaluation or LIFE Many freshwater invertebrates have precise requirements for particular current velocities or flow ranges (Chutter, 1969; Hynes, 1970; Statzner et al., 1988; Brooks, 1990), and certain taxa are ideal indicators of prevailing flow conditions. As well as qualitative responses to flow changes, site specific studies also show that most taxa associated with slow flow tend to increase in abundance as flows decline, whereas most species associated with faster flows exhibit the opposite response (Moth Iversen et al., 1978; Extence, 1981; Cowx et al., 1984; Wright and Berrie, 1987; Boulton and Lake, 1992 and Wright, 1992). Alterations in community structure may occur as a direct consequence of varying flow patterns, or indirectly through associated habitat change (Petts and Maddock, 1994 and Petts and Bickerton, 1997).
Consultancy
Dr. Nick Everall MIFM C Env ���� rnaquaconsult@aol.com ℡℡℡℡ 01246 239344 41
The Lotic-invertebrate Index for Flow Evaluation (LIFE) technique is based on data derived from established 3 minute kick-sweep net sampling of macroinvertebrates in order to assess the impact of variable flows on benthic populations (Extence et. al., 1999). The method links qualitative and semi-quantitative change in riverine benthic macroinvertebrate communities to prevailing flow regimes. The higher the LIFE score in comparable flow-habitat sections of watercourse the higher the prevailing flow conditions and vice versa. A close correlation anticipated by Extence et al., (2011) ‘in many instances’ was between LIFE and PSI. Extence et al., (2011) devised PSI and Extence et al., (1999) devised LIFE, but the relationship in the field has not been tested until recently. There was a clear correlation (r=0.91, p<0.01) between PSI and Life in the Everall (2010) study as recently highlighted in Farmer (2010). It may seem logical that affinity for high flows and low siltation are related, but this was not the complete picture in all preliminary studies to date. Extence et. al. (1999) suggested that when applied to species and family data respectively, the terms LIFE (S) and LIFE (F) are used. Organic pollution and enrichment from Saprobic index Many studies have compared the results of different benthic macroinvertebrate metrics used to assess the impact of organic pollution (Hellawell, 1987, Calow & Petts, 1993, Hauer & Lamberti, 1996 and Eurolimpacs, 2004,). The Average Score Per Taxon (ASPT) used by the Environment Agency with the computer model RIVPACS in the UK has been well correlated with the stress gradient in most stream types but the Saprobic Index worked better than ASPT in those countries (e.g. Germany, Austria and the Czech Republic) where macroinvertebrates were generally identified to a lower (species) as opposed to a higher (genus or family) level of identification (Leonard and Daniel, 2004). Saprobic indexing at the species and family level allowed a greater insight into the nature and quantum of organic pollution in watercourses than other methods since it accounted for species differences in tolerance to organic pollutants (e.g. elevated ammonia and lowering dissolved oxygen regimes) as opposed to generic estimates of whole family responses. The link between biological water quality and the saprobic system of watercourse classification was because benthic invertebrates are important within the stream community as a fundamental link in the food web between organic matter resources and ecosystem fishery health. A standardised method to assess the biological water quality in European watercourses is the saprobic classification system (saprobity = amount of degradable organic material). This classification system is based upon selected index organisms (indicators), whose appearance is related to the impact of degradable organic material. The saprobic value (s) is a number from 1,0 to 4,0. The category groups of the saprobic values are shown in Table 5 overleaf:
Consultancy
Dr. Nick Everall MIFM C Env ���� rnaquaconsult@aol.com ℡℡℡℡ 01246 239344 42
Classification s
oligosaprobic 1,0 - <1,5
oligosaprobic – ß-mesosaprobic 1,5 - <1,8 ß-mesosaprobic 1,8 - <2,3
ß-mesosaprobic – α-mesosaprobic 2,3 - <2,7 α-mesosaprobic 2,7 - <3,2
α-mesosaprobic – polysaprobic 3,2 - <3,5 polysaprobic 3,5 – 4,0
In the calculation of the saprobic classification there are two values that are dedicated to each species: 1. the saprobic value (s) and 2. the indicator value (G) The saprobic value shows the appearance of the species in a specific range of water quality. Some species have a narrow tolerance range, this means that they are good indicators. The specific tolerance of the species is expressed by the indication value. The third term to calculate the saprobic classification is: 3. the frequency (A) of a particular species. Formula for the saprobic index:: S = ∑A*s*G ∑A*G S = saprobic index A = frequency s = saprobic value G = indicator value The latest Saprobic values (s) and indicator values (G) used throughout Europe were obtained by formal permission in writing from and Dr. Everall was granted (password) access to the EUROLIMPACS database (via www.freshwaterecology.info). Interpretation of Saprobic indices for levels of organic pollution and inferred chemical status was provided by Laenderarbeitsgemeinschaft Wasser (LAWA), Mainz, Germany, 1976 shown in Table 6 overleaf:
Consultancy
Dr. Nick Everall MIFM C Env ���� rnaquaconsult@aol.com ℡℡℡℡ 01246 239344 43
Quality class Degree
of
organic
load
Saprobic state Saprobic
index
Usual
BOD5
in mg/L
Usual
NH4-
N in
mg/L
Usual
O2-
minima
in mg/L
I no or
minimal oligosaprobic 1,0-<1,5 1 <0,1 8
I-II small oligo-betamesosaprobic 1,5-<1,8 1-2 ~0,1 8
II mild betamesosaprob 1,8-<2,3 2-6 <0,3 6
II-III critical beta-alphamesosaprobic 2,3-<2,7 5-10 <1 4
III strongly polluted alphamesosaprobic 2,7-<3,2 7-13
0,5- several mg/L
2
III-IV very
strongly polluted
alphamesosaprobic transition zone 3,2-<3,5 10-20 several
mg/L <2
IV extremely
polluted polysaprobic 3,5-<4,0 15 several
mg/L <2
For EA GQA dataset the macroinvertebrate results for organic enrichment expressed as Saprobic index are in fact the best mix of family with species resolution data when and where available. Inorganic (Phosphorous) enrichment from Total Reactive Phosphorous Index or TRPI Eutrophication, defined as the enrichment of waters by nutrients resulting in an array of biological changes, is widespread in the lakes and rivers of industrialised countries (Schindler, 2006 and Lampert and Sommer, 2007). Typical symptoms include increased algae production (Walling andWebb, 1992) and sometimes enhanced growth of higher aquatic plants (Dodds, 2006). Traditionally Water Framework Directive (WFD) biological assessment of nutrient enrichment in watercourses has utilised both plant (macrophyte) and benthic algal (phytobenthos) assessments but these have latterly been found to have some flaws for some watercourse types. It has long been recognised that nutrient enrichment causes complexation of ecosystems through changes in primary producers (algae and plants) with studies variably recording e.g. a reduction in faunal (consumer) biodiversity following changes in species composition (Smith, 2003 and Hilton et. al., 2006) and measurable stress to macroinvertebrate communities (Weitjers et. al., 2009 and Miltner, 2010). During the last decade workers have been developing a diagnostic model based upon a Bayesian belief network to detect total reactive phosphorous (TRP) fingerprints from macroinvertebrate community data in receiving watercourses over a wide geographic area of England and Wales (Paisley et. al., 2003, Everall, 2004, Everall, 2005, Everall, 2010 and Paisley et. al., 2011). Eutrophication often occurs in combination with other anthropogenic stresses in rivers in a way that was historically difficult to disentangle, further disrupting simple relationships between nutrient availability and biological response. In the latest TRP diagnostic model developed by the author with Dr. Martin Paisley at Staffs University the benchmark datasets in the model were screened to minimise the confounding effects of organic pollution and split according to site type and season. This is a new biometric developed by Dr. Everall (Aquascience Consultancy) and Dr. Martin Paisley (University of
Consultancy
Dr. Nick Everall MIFM C Env ���� rnaquaconsult@aol.com ℡℡℡℡ 01246 239344 44
Staffordshire) which is based upon the phosphate and macroinvertebrate studies of Paisley et. al. (2003 and 2011) and Everall (2005 and 2006). The Total Reactive Phosphorous Index or TRPI describes the TRP-sensitive taxa groupings in Table 7 overleaf present in a sample and the metric is calculated from the formula below using the ‘look up’ matrix shown in Table 8 overleaf:
ε Nutrient Scores for A & B TRPI = X 100 ε Nutrient Scores A&B&C&D
The TRPI, unlike some previous biometrics e.g. PSI (Extence et. al., 2011) has to allow for both positive and negative changes in the abundance of TRP indicator macroinvertebrate families associated with the findings from large field datasets upon the impacts of TRP in watercourses (Paisley et. al., 2011). Table 7 - Nutrient (TRP) tolerance bandings Group TRP Tolerance Definition
A Taxa very sensitive to [TRP] B Taxa sensitive to [TRP] C Taxa tolerant to [TRP] D Taxa very tolerant to [TRP] E Taxa indifferent to [TRP] at P>0.05 or excluded from the method for
other reasons.
Table 8 - Nutrient scores based on tolerance bandings and abundance Group TRP Sensitivity Log Abundance. Rating (PSR) 1-9 10-99 100-999 1000+ A Very Sensitive 2 3 4 5 B Sensitive 1 2 3 4 C Tolerant 1 2 3 4 D Very Tolerant 2 3 4 5 E Excluded
A tabular ‘look-up’ matrix is then used for TRP indicator macroinvertebrate families from Paisley et. al. (2011) associated with river site Types, season and alkalinity. For example, Type 1-3 are generally associated with upland rivers and Type 3-5 with increasingly lowland rivers respectively. The model calculation formula then generates the season and river type weighted phosphate-sensitive macro-invertebrate metric, the TRPI and a provisional interpretation scheme for the data is shown in Table 9 below. Effectively, the more TRP sensitive families present the lower the
Consultancy
Dr. Nick Everall MIFM C Env ���� rnaquaconsult@aol.com ℡℡℡℡ 01246 239344 45
TRPI% and the less chemical TRP present in the watercourse at that site at that time but recording fingerprint from previous temporal exposure as with and other biometric index. Table 9 - Look up formula results TRPI Nutrient Condition
81 -100 Very low [TRP] 61 - 80 Low [TRP] 41 - 60 Moderate [TRP] 21 - 40 High [TRP] 0 - 20 Very high [TRP]
Biometric section references only
Boulton, A.J. and Lake, P.S. (1992). The ecology of two intermittent streams in Victoria Australia. III. Temporal changes in faunal composition. Freshwater Biology, 27, 123-138. Brooks, A. (1990). Channelized Rivers Perspectives for Environmental Management. Wiley, Chichester. Calow, P. & G. Petts: The Rivers Handbook I: Hydrological and Ecological Principles; Wiley and Sons, 1993. Chutter, F.M. (1969). The distribution of some stream invertebrates in relation to current speed. Int. Revue ges Hydrobiol., 54, 413-422. Chadd R and Extence C. (2004). The conservation of freshwater macroinvertebrate populations: a community-based classification scheme. Aquatic Conservation: Marine and Freshwater Ecosystems, 14, 597-624. Chutter, F.M. (1969). The effects of silt and sand on the invertebrate fauna of streams and rivers. Hydrobiologia, 34, 57-76. Clements, W.H. and Newman, M.C. (2002). Community Ecotoxicology. Hierarchical Ecotoxicology Series, John Wiley and Sons Ltd., Chichester, 336pp. Commission of the European Communities (CEC), 2000. Directive 2000/60/EC of the European Parliament and of the Council Establishing a Framework for the Community Action in the Field of Water Policy. http://ec.europa.eu/environment/ water/water-framework/index_en.html (last accessed August 2008).
Consultancy
Dr. Nick Everall MIFM C Env ���� rnaquaconsult@aol.com ℡℡℡℡ 01246 239344 46
Cordone, A.J. and Kelley D.W. (1961). The influences of inorganic sediment on the aquatic life of streams. California Fish and Game, 47, 189-228. California Department of Fish and Game, Inland Fisheries Branch: Sacramento, US. Cowx, I.G., Young, W.O. and Hellawell, J.M. (1984). The effect of drought on the fish and invertebrate populations of an upland stream in Wales. Freshwater Biology, 14, 165-177. Davies-Colley, R.J., Hickey, C.W., Quinn, J.M. and Ryan, P.A. (1992). Effects of clay discharges on streams 1, Optical properties and epilithon. Hydrobiologia, 248, 215-234. Environment Agency (1997). Procedures for collecting and analysing macro-invertebrate samples. Environment Agency, Bristol, 82pp. Everall, NC. (2010). The aquatic ecological status of the rivers of the Upper Dove Catchment in 2009. Natural England Commissioned Report NECR046. Natural England: Sheffield. Extence, C.A. (1981). The effect of drought on benthic invertebrate communities in a lowland river, Hydrobiologia, 83, 217–224. Extence C. A., Balbi D.M. and Chadd R.P. (1999). River Flow Indexing using British benthic macroinvertebrates: A framework for setting hydro ecological objectives. Regulated Rivers Research and Management. 15, 543-574. Extence, C.A, Chadd, R.P, England, J., Dunbar, M.J., Taylor, E.D. and Everall, N.C. (2010). The assessment of fine sediment accumulation in rivers using macroinvertebrate community response. BHS Third International Symposium, Managing Consequences of a Changing Global Environment, Newcastle, 2010. Extence, C.A., Chadd, R.P., England, J., Dunbar, M.J., Wood, P.J. and Taylor, E.D. (2011). The Assessment of Fine Sediment Accumulation in Rivers Using Macro-invertebrate Community Response. River Research and Applications, 30pp. Hellawell, J.M. (1986). Biological indicators of freshwater pollution and environmental management. Pollution Monitoring Series. London, Elsevier Applied Science, 546pp. Hauer, F. R. and Lamberti, G. A. (1996). Methods in Stream Ecology, Academic Press, 1996. Hilton, J., O'Hare, M., Bowes, M.J. and Jones, J.I. (2006). How green is my river? A new paradigm of eutrophication in rivers. Science of the Total Environment 365, 66-83. Hynes, H.B.N. (1970). The Ecology of Running Waters. Liverpool University Press, Liverpool, 555pp.
Consultancy
Dr. Nick Everall MIFM C Env ���� rnaquaconsult@aol.com ℡℡℡℡ 01246 239344 47
Hynes, H.B.N. (1973). The Effects of Sediment on the Biota in Running water. in Fluvial Processes and Sedimentation, Proceeding of a Hydrology Symposium, University of Alberta, Edmonton: 653-663. National Research Council, Environment Canada. Moss, D., Furse, M.T., Wright, J.F. and Armitage, P.D. (1987). The prediction of the macroinvertebrate fauna of unpolluted running-water sites in Great Britain using environmental data. Freshwater Biology 17, 41-52. Moth Iversen, T., Wiberg-Larsen, P., Birkholm Hansen, S. and Hansen, F.S. (1978). The effect of partial and total drought on the macroinvertebrate communities of three small Danish streams. Hydrobiologia, 60, 235-242. Paisley, M.F., Walley, W.J., Nikhade, J. and Dils, R. (2003). Identification of the key biological indicators of nutrient enrichment in rivers for use in predictive/diagnostic models. Proceeding of the 7th International Specialised IWA Conference on Diffuse Pollution and Basin Management, Dublin, Ireland. Paisley, M.F., Walley, W.J. and Trigg, D.J. (2011). Identification of macro-invertebrate taxa as indicators of nutrient enrichment in rivers. Ecological Informatics, 6, 399–406. doi:10.1016/j.ecoinf.2011.09.002. Parkhill, K.L. and Gulliver, J.S. (2002). Effect of inorganic sediment on whole-stream productivity, Hydrobiologia, 472, 5–17. Percival, E. and Whitehead, H. (1929). A quantitative study of some types of stream bed. Journal of Ecology, 17, 282-314. Petts, G.E. and Maddock, I. (1994). Flow allocation for in-river needs, in Calow, P. and Petts, G.E. (Eds), The Rivers Handbook, Volume 2. Hydrological and Ecological Principles, Blackwell Scientific Publications, London. Petts, G., Maddock, I., Bickerton, M. and Ferguson, A.J.D. (1995). Linking hydrology and ecology: the scientific basis for river management. In: The Ecological Basis for River Management. Edited by D..M. Harper and A.J.D. Ferguson. John Wiley & Sons, Chichester. Petts, G.E. and Bickerton, M.A. (1997). River Wissey lnvestigations: linking hydrology & ecology. Execective summary, Environment Agency Project Report, 01: 526 :1A, Environment Agency, Bristol, UK. Richards, C. and Bacon, K.L. (1994). Influence of fine sediment on macroinvertebrate colonization of surface and hyporheic stream substrates. Great Basin Naturalist, 54, 106–113. Richards, C., Haro R.J., Johnson L.B. and Host G.E. (1997). Catchment and reach-scale properties as indicators of macroinvertebrate species traits. Freshwater Biology, 37, 219-230.
Consultancy
Dr. Nick Everall MIFM C Env ���� rnaquaconsult@aol.com ℡℡℡℡ 01246 239344 48
Ryan PA. 1991. Environmental effects of sediment on New Zealand streams: a review. New Zealand Journal of Marine and Freshwater Research, 25, 207-221. Statzner, B., Gore, J.A. and Resh, V.H. (1988). Hydraulic stream ecology: observed patterns & potential applications. Journal North American Benthological Society, 7, 307-360. Walley, W.J. and, Fontama, V.N., 1998. Neural network predictors of average score per taxon and number of families at unpolluted river sites in Great Britain. Water Research 32 , 3, 613-622. Woodiwiss, F.S. (1964). The biological system of stream classification used by the Trent River Board, Chemy. Indust., 11, 443-447. Wright, J.F. and Berrie, A.D. (1987). Ecological effects of groundwater pumping and a natural drought on upper reaches of a chalk stream. Regulatory Rivers, 1, 145-160. Wright, J.F. (1992). Spatial and temporal occurrence of invertebrates in a chalk stream. Berkshire, England, Hydrobiologia, 248, 11-30.
Wright, J.F., Sutcliffe, D.W. and Furse, M.T. (2000). Assessing the Biological Quality of Fresh Waters. RIVPACS and Other Techniques. Freshwater Biological Association, Windermere.
Recommended