Know Your Rivers - Salmon and Sea Trout Catchment Summary River Wye
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Know Your Rivers -
Salmon and Sea Trout
Catchment Summary
River Wye
Introduction
This report describes the status of the salmon and sea trout populations in the Wye
catchments. Bringing together data from rod catches, stock assessments and juvenile
monitoring, it will describe the factors limiting the populations and set out the challenges
faced in the catchment.
Action tables set out habitat improvements to restore freshwater productivity of salmon and
sea trout populations. These tables also include some work which will be carried out by our
partner organisations, not just Natural Resources Wales (NRW).
NRW has a duty, defined in the Environment (Wales) Act 2016 to have Sustainable
Management of Natural Resources (SMNR) at the core of everything that we do. By applying
the principles of SMNR in all of our activities - from agriculture, forestry and flood defence to
development planning - we are undertaking catchment-wide initiatives that will deliver for
fish stock improvements. Our reports highlight the importance of considering the whole
catchment when identifying and addressing fisheries issues; and of working with partners.
NRW is committed to reporting on the status of salmon stocks in all of our principal salmon
rivers for the Salmon Action Plans and condition assessments under the Habitats Directive
in SAC rivers; all fish species in all of our rivers are reported for the Water Framework
Directive (WFD). This report will fulfil these commitments and provide an informative and
useful summary of stock status and remedial work planned, for our customers, specifically
anglers, fishery and land owners; as well as our partners.
Catchment
The River Wye rises from an altitude of 741m in the Welsh mountains at Plynlimon and at
250km in length it is the 6th largest river in the UK. The principal tributaries are the Elan,
Ithon, Irfon, Lugg and Arrow, and the Monnow. The Lugg and Arrow rise in Wales and then
flow east through England before joining the Wye at Hereford, in addition significant parts of
the Monnow catchment and main river Wye also lie within England.
Land-use in the catchment is predominantly agriculture (with some woodland and residential
areas). Higher grounds and poorer soils to the north and west supporting largely
monoculture conifer forestry and pastoral farming, give way to higher quality and more
intensive arable agriculture in the south and east of the catchment. In the upper catchment
the headwaters of the Elan River are impounded, creating the Elan Valley system of
reservoirs.
The Wye catchment is one of great ecological value. It has many SSSIs and the main river
and many of its tributaries are designated as a riverine SAC under the Habitats Directive for
ten rare or threatened nationally and internationally important species. These species
include seven fish species - Atlantic salmon; allis and twaite shad; brook, river and sea
lamprey; and bullhead.
www.cyfoethnaturiolcymru.gov.uk www.environment-agency.gov.uk
www.naturalresourceswales.gov.uk Page |1
The River Wye is a well-established and nationally significant salmon rod fishery with the most recent reported rod catch (2015) of 1212. Salmon are found throughout the Wye catchment except in the upper reaches of the Elan, above the reservoirs. Fish passes installed at numerous weirs across the Lugg and Arrow, and at Osbaston on the Monnow have opened up these catchments and have resulted in the inclusion of these catchments in the Salmon Conservation Targets. The Wye catchment has suffered from declining rod catches, and after some years of promoting voluntary catch and release, a Wye specific byelaw was introduced in June 2012 which mandated the release of all rod caught salmon. A small number of sea trout are caught on the Wye (84 fish in 2015). Because sea trout rod catch is low and they are rarely targeted by anglers on the wye, we will not further consider sea trout within this report. The River Wye and its tributaries are also a locally important brown trout, coarse fish and grayling fishery. Elver fishing takes within the tidal reaches of the Wye. www.cyfoethnaturiolcymru.gov.uk www.environment-agency.gov.uk www.naturalresourceswales.gov.uk Page |2
Rod catches
The following graph shows the total declared rod catches, including numbers released or
killed for salmon on the Wye, since 1960. Returns are collected from the Wye Owners Group,
and more recently we use the data which the Wye and Usk Foundation (WUF) collect from
the fishery owners. Release data is taken from the rod licence returns, these are likely to be
a slight underestimate as the full returns are invariably lower than the owners returns.
The trend is dramatically downwards since the 1960s, but has considerable variability within
it, peaking at 7854 in 1967 and dropping as low as 320 in 1992. Signs of an upturn in the
trend are apparent in recent years.
Salmon rod catch, River Wye
9000 1960-2015
No. of salmon
6000
Released
Killed
3000
0
1960
1964
1968
1972
1976
1980
1984
1988
1992
1996
2000
2004
2008
2012
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www.naturalresourceswales.gov.uk Page |3
Monnow Fish Counter
The Monnow catchment had been entirely inaccessible to migratory fish for the best part of
300 years, due to the large weir at Osbaston. In 2008 we installed a pool and traverse fish
pass and a Vaki river watcher fish counter to assess the extent of the re-colonisation of the
catchment. The Vaki fish counter produces images using infrared light. As fish pass through
the infrared scanner plates an image is produced. Underwater cameras were also installed
to help with species identification. With the opening of Osbaston fish pass and the removal
of Kentchurch weir (in 2011), 200km of the river Monnow catchment have become
accessible for migratory fish. Since Osbaston fish pass was opened, salmon and large
numbers of brown trout have been recorded migrating upstream.
Vaki image of a Salmon
Camera image of a Salmon
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www.naturalresourceswales.gov.uk Page |4
Stock Status
Conservation of Salmon
Salmon stock status is assessed through the use of ‘Conservation Limits’ (CL) which
provide an objective reference point against which to assess the status of salmon stocks
in individual rivers. The numbers of salmon a river can produce (and consequently the
catches that the stocks support) are a function of the quality and quantity of accessible
spawning and rearing area. This is why, in general, big rivers have larger catches and have
correspondingly bigger total spawning requirements (or Egg Deposition Targets - EDT)
than small rivers. Thus, for any given rivers there should be an optimum level of stock
which the CL seeks to protect. The Conservation Limit represents the number of eggs that
must be deposited each year within a given catchment in order to conserve salmon stocks
in the future.
River Wye
Estimates of egg deposition, and compliance with conservation limit
3.0
2.5
Log (egg deposition, millions)
2.0
1.5
1.0
0.5
0.0
2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
Year
The Conservation Limit for the Wye is set at 38.57 million eggs, represented by the red
line on the graph. The current estimate of number of eggs is being deposited is marginally
below the Conservation Limit which puts the Wye salmon stock ‘Probably At Risk’ but
with an improving trend. In 5 years’ time, the predicted status of the Wye salmon stock will
be ‘Probably Not At Risk’. Based on current and predicted trends, the Wye salmon stock
will continue to improve. This is a very positive improvement on recent years.
To describe the estimate of compliance as salmon available to spawn; we would need
around 8000 salmon running the river to spawn to meet the conservation limit, our estimate
for 2015 was 7300 fish.
www.cyfoethnaturiolcymru.gov.uk www.environment-agency.gov.uk
www.naturalresourceswales.gov.uk Page |5Juvenile Abundance Monitoring
The following maps show the results of the routine juvenile salmonid population surveys
from 2015 in Wales and England. The surveying programme (and responsibility for the river)
is split between Natural Resources Wales, who are responsible for the Welsh Wye, and the
Environment Agency on the English side. Results from the Monnow salmon investigations
can be seen in the Appendix.
The symbols display the National Fish Classification Scheme (NFCS) grades which have
been developed to evaluate and compare the results of fish population surveys in a
consistent manner. The NFCS ranks survey data by comparing fish abundance at the survey
sites with sites nationally where juvenile salmonids are present. Sites are classified into
categories A to F, depending on densities of juvenile salmonids at the site. The following
table shows the values and classification of NFCS.
Grade Descriptor Interpretation
A Excellent In the top 20% for a fishery of this type
B Good In the top 40% for a fishery of this type
C Fair In the middle 20% for a fishery of this type
D Fair In the bottom 40% for a fishery of this type
E Poor In the bottom 20% for a fishery of this type
F Fishless No fish of this type present
Juvenile salmon were recorded in at 22 of 28 Wye sites in 2015; the exceptions being the
sites on the Monnow and upper Lugg and upper Arrow catchments.
Salmon have never been recorded at the three Monnow sites due to man-made barriers,
some but not all of which have now been made passable or removed. The Lugg, Arrow and
Hindwell brook sites also have migration barriers, and records of salmon are patchy in these
areas.
Eleven of the 28 sites had salmon fry classifications of Excellent (A) or Good (B), although
salmon parr classifications were considerably lower, with none Excellent and just three
Good.
Juvenile brown trout were recorded at 27 of 28 Wye sites in 2015; the exception being the
site on the Ithon at Dol y Dre which has only had three records of trout since 1985 and none
since 2004.
Just eight of the 28 sites had trout fry classifications of Excellent (A) or Good (B), and as
seen with the salmon parr, trout parr and adult (>0+) classifications considerably lower, with
none Excellent and just two Good.
www.cyfoethnaturiolcymru.gov.uk www.environment-agency.gov.uk
www.naturalresourceswales.gov.uk Page |6www.cyfoethnaturiolcymru.gov.uk www.environment-agency.gov.uk www.naturalresourceswales.gov.uk Page |7
Juvenile salmon distribution within the Wye catchment In 2014 a full spatial programme, comprising 179 sites, was undertaken on the Wye. The distribution of juvenile salmon from these surveys is shown in the map below. Data from a further 44 sites surveyed in 2013 in the Irfon catchment as part of the ISAC project; and 18 in 2013 and 2015 on Monnow and Lugg are also included for a more complete picture. As can be seen, juvenile salmon were recorded at most of the sites in the catchment (162/241). The majority of sites with salmon absent are on the upper Lugg, Lugg and Arrow tributaries, the Frome and Lodon, and the Monnow catchments, all of which have migratory access problems that are not yet fully resolved. It is worth noting that for the first time in many years, salmon were found at every site on the main Lugg and Arrow up to the English / Welsh border. NB – the absences which appear on this map to be on the River Lugg downstream of Hereford are in fact on the Wellington and Moreton Brooks. www.cyfoethnaturiolcymru.gov.uk www.environment-agency.gov.uk www.naturalresourceswales.gov.uk Page |8
Juvenile Trend Analysis Trends in the population data for juvenile salmon and brown trout were assessed using Bayesian statistical linear and non-linear models. The linear model fits a straight line to the data in order to determine whether a trend (upwards or downwards) is present. The statistical significance of the trend is denoted by the P value, P>0.975 indicates a statistically significant upward trend (or a 97.5% chance of an upward trend) and P0+ densities have also shown some improvement. www.cyfoethnaturiolcymru.gov.uk www.environment-agency.gov.uk www.naturalresourceswales.gov.uk Page |9
Juvenile Salmon Trends
1 95% Confidence Interval around trend
median
Temporal variation around trend, with 95% CI
0
Log Density
-1
-2
-3
1985
1987
1989
1991
1993
1995
1997
1999
2001
2003
2005
2007
2009
2011
2013
2015
Linear analysis of salmon population in Wye catchment, 1985 to 2015 (P = 0)
2
Median trend
Temporal variation around trend, with 95% CI
95% confidence interval around trend
1
Log Density
0
-1
-2
1997
1985
1987
1989
1991
1993
1995
1999
2001
2003
2005
2007
2009
2011
2013
2015
Non-linear analysis of salmon population in Wye catchment, 1985 to 2015
1
0
Log Density
-1
-2 95% confidence interval around trend
median
Temporal variation around trend, with 95% CI
-3
2008
2002
2003
2004
2005
2006
2007
2009
2010
2011
2012
2013
2014
2015
Linear analysis of salmon population in Wye catchment, 2002 to 2015 (P = 0.9271)
www.cyfoethnaturiolcymru.gov.uk www.environment-agency.gov.uk
www.naturalresourceswales.gov.uk P a g e | 10Juvenile Brown Trout Trends
95% confidence interval around trend
-1 Temporal variation around trend, with 95% CI
median
-2
Log Density
-3
-4
-5
1985
1987
1989
1991
1993
1995
1997
1999
2001
2003
2005
2007
2009
2011
2013
2015
Linear analysis of brown trout population in Wye catchment, 1985 to 2015 (P = 0.0184)
Median trend
0 Temporal variation around trend, with 95% CI
95% confidence interval around trend
-1
Log Density
-2
-3
-4
1991
1985
1987
1989
1993
1995
1997
1999
2001
2003
2005
2007
2009
2011
2013
2015
Non-linear analysis of brown trout population in Wye catchment, 1985 to 2015
95% confidence interval around trend
median
-1 Temporal variation around trend, with 95% CI
-2
Log Density
-3
-4
-5
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
Linear analysis of brown trout population in Wye catchment, 2002 to 2015 (P = 0.9962)
www.cyfoethnaturiolcymru.gov.uk www.environment-agency.gov.uk
www.naturalresourceswales.gov.uk P a g e | 11Fisheries Actions – Wye
Timescales
Site Action Benefits Lead Partner(s)
for delivery
Barriers in Wales to be addressed: The last remaining significant
Crucorney Weir (SO3172220959) rock ramp below barriers to salmon migration in the
weir; work is waiting suitable legal mechanisms for Monnow catchment. Making them NRW WUF 2017
Monnow delivery accessible increases the spawning
Barriers in England to be addressed: habitat available to salmon and EA WUF 2016
Monnow at Clodock (SO3269427496) - managed trout; improving population size
through enforcement action. and viability.
Barriers in Wales to be addressed:
Dolley Green Weir (SO275655) – lowering or removal. NRW WUF 2016/17
Alternative Mitigation Action
Gerwen (tributary) pipe bridge at SO223677 TBC WUF TBC
Belddfa (tributary) weir/pipe bridge at SO207684 TBC WUF TBC
Barriers in England to be addressed, funded from FCRM More habitat accessible to salmon
Lugg Environment linked funding: and trout; increased population
Ballsgate (SO418660) fish passage option and build size and viability.
EA WUF 2016/17
Lugg Green (SO451619) reduction easement
2016
Crowards Weir (SO484605) option appraisal
2018
Coxall Weir (SO477606) option appraisal 2016
Gilberts Weir (SO465613) option appraisal 2016/17
Holgate (SO462613) option appraisal 2016/17
Lyepole Weir (SO392651) removal option appraisal 2016/17
Barriers in Wales to be addressed:
Llanpica Weir (SO2330750258) – lowering or rock NRW 2016/17
More habitat accessible to salmon
ramp. Alternative Mitigation Action
Arrow and trout; increased population WUF
Barriers in England to be addressed:
size and viability.
Turners Mill (SO298564), to be managed through EA 2016
enforcement action.
www.cyfoethnaturiolcymru.gov.uk www.environment-agency.gov.uk
www.naturalresourceswales.gov.uk P a g e | 12Fisheries Actions – Wye
Garth Dulas Habitat remains accessible to
Maintenance on fish pass at Garth to improve fish migration NRW WUF 2016
(Irfon) spawning salmon and trout
Barriers to be addressed:
Fernant (A470 crossing). Falls with fence causing a More habitat accessible to salmon
Aran (Ithon) blockage. and trout; increased population NRW WUF TBC
A483 (SO0888073670). Pipebridge size and viability.
Dolau tributary. Stone weir in village
Upper Ithon Habitat improvement
Cooler, cleaner rivers, mitigating
(other sites As part of the Keeping Rivers Cool initiative, sites have been
climate change and so benefitting
in the Wye identified for fencing in order to promote natural re-generation NRW WUF 2016/17
salmon and trout spawning and
to be of trees/shrubs leading to increased shade and associated
egg/juvenile survival.
confirmed) reductions in temperatures. Alternative Mitigation Action.
Habitat Improvement
Financed by fisheries improvement funds from Rod Licence
Revenue; the Joint Working Partnership Fund and Reduced siltation, improved HWT
Whole Competitive Fund spawning gravels. Improved NRW WUF
Riparian improvements 2016
catchment juvenile habitat. Restoration of EA NE
In-stream habitat work favourable condition. FC
Invasive plant control
Farm liaison - better land management practices
Allowable catch for the Historical
Ongoing
Instruments is dictated by
Severn Manage Exploitation NRW until 2018
management levels set in the EA
Estuary Management of the Severn Estuary mixed stock net fishery. NE review of
habitats regulatory assessment to
NLO
protect Wye Salmon stocks
www.cyfoethnaturiolcymru.gov.uk www.environment-agency.gov.uk
www.naturalresourceswales.gov.uk P a g e | 13Fisheries Actions – Wye
Agriculture
Focusing on the Llynfi, Trothy and Ithon catchments in Wales;
Lugg in England WUF
Wet weather inspections FC
Whole Improved water quality for salmon NRW
Water quality investigations MCC Ongoing
catchment and trout EA
Farm compliance checks and associated ADAS
enforcement. GWT
Referral to Rural Payments Agency (RPA) when x-
compliance breaches identified – England
Water Framework Directive
We will continue to monitor the status of the environment Water environment protected and
and investigate causes of failures. improved.
Whole NRW WUF
Refer to Severn River Basin Management Plan for more Ongoing
catchment EA WCP
details More WFD waterbodies achieving
https://www.gov.uk/government/publications/severn-river- Good Ecological Status.
basin-district-river-basin-management-plan
Wye Catchment Partnership
Improved water quality in the Wye
Continue to develop a broad based partnership of interested
catchment.
parties & bodies with the objective of addressing all the
Whole Projects effectively developed and NRW
issues affecting the Wye catchment, specifically to improve EA Ongoing
catchment delivered. WUF
water quality and quantity.
Opportunities and issues
Refer to Wye Catchment Partnership for more details
highlighted and discussed.
www.wyecatchment.org
www.cyfoethnaturiolcymru.gov.uk www.environment-agency.gov.uk
www.naturalresourceswales.gov.uk P a g e | 14Fisheries Actions – Wye
Habitats Directive Review of Licenced Abstraction
Consents
Licence
NRW licences water abstractions from the river Wye. Over
DCWW changes
several years we have been reviewing these licences to Enough water will remain in the
Whole NRW STW 2016
ensure they do no harm to the features of the Wye Special river to allow salmon and other
catchment EA WUF
Area of Conservation (SAC). Salmon are a feature of the Wye features of the SAC to thrive.
Compliance
SAC. Many agricultural licences have already been changed.
by 2018
Changes for the remaining water company licences are now
being completed.
NRW Natural Resources Wales NE Natural England MCC Monmouthshire County
Council
EA Environment Agency WCP Wye Catchment Partnership GWT Gwent Wildlife Trust
DCWW Dwr Cymru Welsh Water STW Severn Trent Water FC Farming Connect
WUF Wye and Usk Foundation HWT Hereford Wildlife Trust
www.cyfoethnaturiolcymru.gov.uk www.environment-agency.gov.uk
www.naturalresourceswales.gov.uk P a g e | 15APPENDIX In 2014 and 2015 we undertook investigations into the spread of salmon in the Monnow catchment. This follows the installation of the fish pass at Osbaston (2008) and the removal of the weir at Kentchurch (2011). In 2015, several 5-minute riffle surveys were carried out in addition to the three temporal (one Welsh W020 and two English Llanveynoe and Abbey Dore Court) sites in the catchment. The following map shows the results of this investigation using a simple presence absence of juvenile salmon. www.cyfoethnaturiolcymru.gov.uk www.environment-agency.gov.uk www.naturalresourceswales.gov.uk P a g e | 16
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