Crayfish Action Sheffield
EXECUTIVE SUMMARY REPORT
1.
Introduction
1.1.
Crayfish Action Sheffield (CAS) has been a wide ranging project that has set out to deliver
through 13 key aims a range of initiatives and targets. The overall output of the aims can be
summarised in two basic objectives:
 To protect and enhance the white clawed crayfish population in Sheffield
 To raise public awareness of the conservation requirements of white clawed
crayfish.
1.2.
There was a recognition for a number of years within Sheffield City Council, the
Environment Agency and a number conservation organisations including the Sheffield
Wildlife Trust and the Sorby Natural History Society that native crayfish (Autropotamobius
pallipes), an important indicator of a healthy aquatic environment were threatened with
extinction in the district. These concerns were responded to by studies undertaken in the
Sheffield district one of which was the Crayfish in the Sheffield District (Eades 2009) which
proposed several actions that would be necessary for the conservation of native crayfish in
Sheffield. These included: raising awareness of crayfish issues with partner organisations
and the general public, the use of various barrier to protect native crayfish and improving
water quality and habitats. These concerns, articulated through the work of Phil Eades work
and the willingness of key players to address them became the basis of an ambitious
project.
2.
Background to the CAS project
2.1.
The establishment of the Sheffield Crayfish Working Group brought together a number of
people who had a keen interest in the conservation of native white clawed crayfish in the
Sheffield district. The long history of nature conservation, biological recording and the
unique character of Sheffield’s urban rivers that originate in moorland catchments also
provided significant incentives to tackle this priority issue. It had been identified by Eades
(2009) and through survey work carried out by locally based freshwater ecologists that the
influx of non-indigenous crayfish species (NICS) represented by the American signal crayfish
(Pacifastacus leniusculus) posed a threat to Sheffield’s existing population of white clawed
crayfish. The outbreak of crayfish plague in 2009 and the subsequent rescue of native
crayfish made it clear that the white clawed crayfish in Sheffield were under threat and
action was required.
2.2.
The Crayfish Action Sheffield project was established through the actions of the Ecology
Unit at Sheffield City Council, local ecologists, the Sheffield Crayfish Working Group and the
generous funding of the Esmée Fairburn Foundation. The project officer was based at the
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Ecology Unit offices which provided admin support and access to data management and GIS
facilities. The project was established in April 2010 and has delivered successfully over its
two year life.
3.
National Conservation Strategy for White Clawed Crayfish
3.1.
Leading crayfish ecologists have been seeking to emphasise the need for both national and
local initiatives to help secure the survival of white clawed crayfish conservation. Peay
(2011) discussed this need by identifying the UK Biodiversity Action Plan for white clawed
crayfish 1995 as the first UK strategy for this species. A growth in crayfish conservation
groups and local initiatives developed a momentum in recognising that the threat to native
crayfish was becoming more evident and that the aim of the BAP ‘attempt to maintain the
present distribution by limiting the spread of crayfish plague, limiting the spread of nonnative species and by maintaining habitat conditions’ had not been achieved. The
Environment Agency developed a 5 year Biodiversity Strategy in 2009 (Christmas 2009): it
stated that it would require ‘ regional delivery plans appropriate to the needs of the
regional and conservation need’ (Christmas 2009). The understanding that a catchment
scale approach was required led to further work to provide a ‘toolkit’ in order to risk assess
catchment areas for large scale conservation strategies (Peay et al. 2011) The approach
recommended using a flowchart with a range of topics to assess the specific needs of a
catchment area. These topics are :
 the existing status and trend of white claw population in the catchment
 the incidence or risk of crayfish plague.
 the risk of non native crayfish in the catchment
 the water quality especially from anthropogenic influences and ;
 the condition of the physical habitat
3.2.
The topics provide a practical guide through the necessary steps that have to be addressed
if the issues of crayfish conservation are fully considered. Parts 4 to 8 of this executive
report will use the above topics to summarise the achievements of the CAS project in
relation to the topics. This will ensure the range of achievements and outcomes relate to a
way forward for native crayfish conservation within catchment scale strategy. This will then
be followed by a brief account of the CAS project achievements and a way forward section.
4.
CAS Project Summary
4.1.
The existing status and trend of white claw population in the catchment- The survey data
available at the start of the project was from a range of sources and suggested that
recording of white clawed crayfish and NICS had been included in general freshwater survey
work either through statutory agencies, local authorities or naturalist societies. The CAS
project developed a survey strategy that would target the main tributaries that run
generally west/east through Sheffield . By targeting specific waterways and tributaries of
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the R. Don, more immediate information could be gained about the location of strong
populations of white clawed crayfish, the extent of NICS expansion especially in water
courses where they may threaten native species and identify stretches of river where there
is an absence of all crayfish species. The surveys identified two strong populations of white
clawed crayfish on the Porter Brook and Limb Brook. The compilation of records over the
preceding decades along with a tranche of new records from CAS surveys provided the
spatial/temporal data that could be mapped through GIS applications. This in turn provided
indications of trends and distributions. Although more work can be done in this area to
increase the accuracy of the distribution mapping, the survey programme provided
valuable information on location and level of threat from NICS to native population
centres. All of the survey results have been made available to a range of individuals and
organisation for academic/research use thus increasing the value of the data. The survey
and recording of crayfish was supervised by experienced ecologist but a number of
volunteers who participated in the surveys gained valuable experience in survey, biometric
recording and crayfish handling throughout the survey programme. The output of the
survey programme also informed the Ark site selection process, identifying potential donor
population and increased knowledge of crayfish movements. From that information Ark
sites were selected with more confidence about their potential success.
4.2.
Extending a survey programme into a catchment scale operation would require coordination by statutory agencies managed in-house or contracted out. The management of
data across a range of Biological Records Centres would require regional co-ordination by
an umbrella organisation. In the Don catchment this is the Yorkshire and Humber
Environmental Data Network. This in turn would require GIS provision to provide mapping
and analysis and data interpretation. There would also be issues of the match between
catchments and local authority /BRC boundaries. The CAS experience of survey
programming, involving volunteers and data handling and management would be of value
to a wider survey programme.
5.
The incidence or risk of crayfish plague. Prior to the establishment of the CAS project an
outbreak of crayfish plague forced local ecologists, members of the Crayfish Working
Group and Sheffield City Council to carry out a rescue operation which then involved the
Environment Agency providing access to their quarantine facilities in North Yorkshire.
While the operation required careful handling procedures due to the infectious nature of
crayfish plague, the outcome of the operation provided a new Ark site upstream from the
plague occurrence. The involvement of volunteers also contributed to the successful
outcome of the operation. Combatting crayfish plague can only be achieved through
adherence to strict biosecurity measures from the single individual to a large scale project
perspective. Cleaning fishing tackle, wellingtons and fishing nets of individuals is as
important as the biosecurity required when pumps, wooden shuttering, sand bags and
plant are used in works in or near to water bodies. By creating a Method Statement for
such works the CAS project has ensured that all works carried out by or on behalf of
Sheffield City Council will adhere to the most stringent biosecurity to ensure that crayfish
plague is not transferred from one water body to another. It is hoped that the Method
Statement will become more widely distributed and accepted. Getting the message of
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biosecurity across to other waterway users: canoeists, anglers and children with fishing
nets is a matter of a consistent message in the right place as frequently as possible.
Bankside surveys with anglers and discussions about their attitude to crayfish plague and
NICS have proved to be valuable in reinforcing the message about biosecurity.
5.1.
Taking biosecurity measures to combat crayfish plague into a larger project should not pose
great difficulties if the biosecurity Method Statement or a similar document is approved by
all of the parties involved. Historical data on the incidence of crayfish plague would be
valuable in identifying any large scale pattern of occurrence and researching factors
influencing its movement and distribution. A wider scale programme of raising the
awareness of crayfish plague amongst river users should really consider how resources can
be used most effectively and the use of volunteer ambassadors amongst anglers and other
groups to provide a consistent message.
6.
The risk of non- native crayfish in the catchment. The CAS survey programme has
provided clear evidence of the threat to native crayfish from NICS. This has shown where
priority actions should be directed so that habitat improvements and other initiatives are
not benefiting non-native species. The risk of invasion from NICS takes into account the
use of barriers which Peay (2011) identifies as being able to prevent or at least significantly
delay invasion by NICS if they are substantial and configured correctly. While barriers could
be a useful tool in the conservation of native crayfish they can also be considered as
‘adverse features’ under the Water Framework Directive. This is a factor that should
receive further consideration as the Don Catchment Rivers Trust look towards further
work to facilitate the movement of migratory fish in the catchment rivers. The Ark sites
that have been established through the CAS project could not have functioned were it not
for the existence of substantial barriers which will hopefully make them biosecure. Where
crayfish are moved through human activity it is more difficult to find a single solution. The
CAS project has used a wide range of publicity and public engagement events to first of all
inform interest groups such as anglers of the dangers of spreading NICS: and secondly the
general public about the threat to our native crayfish. As a project legacy further work is
being carried out by an undergraduate student which will identify relevant research in this
field. Other research work is being undertaken to identify the movements and distribution
over time of signal crayfish in the Don catchment rivers.
6.1.
The research project to establish a distribution pattern for signal crayfish in the Sheffield
district will provide a methodology for further work to extend survey work into a wider
catchment are. Co-ordination of survey data as mentioned in 4.2 above will be important in
planning any large scale strategy to prevent and restrict further movements of NICS. It may
be that a strategy which takes on a type of ‘managed retreat’ (Peay 2011) will be the most
effective way of preserving native crayfish populations where there are substantial
numbers and barriers to movement, both physical and based on raised public awareness.
7.
The water quality especially from anthropogenic influences Poor water quality can
exclude native crayfish from otherwise physically good habitats which in turn may
pressurise populations over a restricted distribution. The CAS project identified water
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quality issues as being both vitally important to the conservation of native crayfish but also
difficult to address even over a two year period. Land management in the headwater areas
of the Don tributaries is generally pastoral and or open moorland. Being able to
communicate with a large number of land owners and riparian managers proved to be
difficult due to lack of time and the difficulties in arranging meetings. The pressures of
farming may mean that issues of run-off and streamside poaching are low priority and
getting these issues more fully appreciated may require much more in the way of
resources and a strategic approach through Countryside Stewardship and associated cross
compliance measures such as soil protection plans. These will also broadly contribute to
the achievement of Water Framework Directive goals on water quality. The influence of
other forms of pollution seem to have diminished with tighter environmental controls and
a general decline in manufacturing but there are still threats to water quality through
sewage pollution incidents which still seem to occur at rare times notwithstanding water
treatment and flood management improvements that have recently taken place. Water
quality testing in native crayfish populated watercourses has been carried out over a the
past 3-4 years by the University of Sheffield using RIVPACS analysis. Such sampling over a
number of years will be extremely valuable in being able to manage crayfish conservation.
7.1.
Transferring water quality standards to a catchment scale project would obviously place
responsibilities onto the Environment Agency in respect of discharges into water courses.
However the Flood and Water Management Act 2010 will place greater responsibilities on
local authorities to manage rivers and other water courses. Extending crayfish conservation
into a catchment scale project would require additional information both temporal and
spatial on water quality to be made available so that problem areas would be identified and
cross referenced with crayfish records.
8.
The condition of the physical habitat. The relationship between the presence of native
crayfish and physical habitat has been commented upon by Sheffield based freshwater
ecologist, Paul Bradley “ The native species is associated with a diverse freshwater
community and valued traditional fishing interests such as fly-fishing for indigenous brown
trout. The non-native species is associated with declining freshwater biodiversity and
potentially severe impacts on traditional recreational fishing.”(Pers com.). There has been
a link between the CAS project and local river environment organisation such as the
SPRITE, an organisation that promotes sustainable fly fishing and is deeply involved in
environmental improvement projects in association with the EA. The CAS project officer
linked with SPRITE and worked on ways of including native crayfish in their publicity on
sustainable fisheries management in urban rivers.
8.1.
There are significant issues of scale and where to direct effort and resources to improve the
physical habitat of watercourses on a catchment scale. Again this may be a matter of
further survey work identifying priority areas where native crayfish can benefit. Linking in
with the Environment Agency and the Don Catchment Rivers Trust can provide access to
projects and initiatives that are linked with the Water Framework Directive.
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9.
Findings of the CAS project
9.1.
As an executive summary this is not a precise analysis of outcomes and findings but an
expression of the general success that the project has achieved and how it has improved
the conditions for crayfish conservation in the Sheffield district and hopefully beyond. Two
local ecologists who have made important contributions to the success of the project have
commented:
“Perhaps the most important message to come out of the Sheffield (CAS) project is the folly of
allowing continued commodification of such an aggressive and invasive species in this country and
the urgent need for Defra to put in place much stricter restrictions- not only to protect our native
species but also to conserve the amenity and economic values associated with indigenous
freshwater communities.”
Paul Bradley, March 2012
And:
“My involvement with the CAS project over the past two years has been very fruitful involving the
translocation, quarantine and introduction of white clawed crayfish into a new Ark site in the
Porter Valley, strategic surveys for crayfish throughout Sheffield and the translocation of white
clawed crayfish to a second Ark site in the Limb valley. The work has been of great personal and
professional interest to me and it is very satisfying to have ben involved in a project that has been
of direct conservation benefit to a threatened species”
Dr Phil Eades, March 2012
9.2.
The involvement of volunteers in surveying and data collection has been an important
function of the project. Training a large number of people in crayfish conservation has been
a significant outcome and one that is reflected in their enthusiasm. The high spot for many
volunteers was direct involvement with crayfish rescue, physical searches and full
involvement in the establishment of two Ark sites. Public perceptions through attendance
at large public events have been changed with those who were engaged with. It was found
that a majority of the public had no idea that white clawed crayfish existed in our local
waters or even in the UK. This helped the conservation message to be more meaningful and
informed people on how they could help and contribute. Several volunteers were recruited
in this way.
9.3.
The approach to anglers and other leisure user groups concentrated on publicity on site at
angling venues. This warned anglers of the dangers posed by non native crayfish and signal
crayfish in particular. The bankside survey of anglers towards the end of the project did
identify some increased awareness but it is accepted that more work could be done in the
future with this group who are important users of our local rivers. A lifelong local angler
was recruited to act as an ambassador to help pass the message onto to other anglers that
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he came across and further recruitment such as this is a possible way forward for raising
awareness amongst anglers.
9.4.
The creation of two ark sites exceeded expectations and has put Sheffield at the forefront of
white clawed crayfish conservation in the UK along with several other partners. These
partners in crayfish conservation have shared best practice through conference
proceedings and other communications. The CAS project was helped in its achievements
through having broad involvement with other parties within the Sheffield district and
throughout the UK. Local ecologists Paul Bradley and Dr Phil Eades have been invaluable in
offering advice and their skills to the project. Organisation such as the University of
Sheffield, Environment Agency. Sheffield and Rotherham Wildlife Trust, and Natural
England have been involved in the CAS project in a variety of ways.. Being open about
sharing data, experiences and best practice methods has been essential to ensure that
crayfish conservation moves forward. A bid to fund the work of the informal Sheffield
Crayfish Monitoring Group has been submitted to the Don Catchment Rivers Trust and if
successful will provide a valuable legacy to maintain some of the important project
outcomes.
9.5.
Trying to influence land owners who have land next to important water courses has not
been wholly successful as time is needed to meet a range of individuals and maintain
contact with them to. Maintaining contact is important in these cases where relatively
straightforward measures can have a significant impact on reducing negative impact on
rivers. The Method Statement to cover works near water is a means by which a great deal
of coverage can be achieved with concentrated effort. If such a Method Statement can
achieve its conservation objectives and at the same time make sense to and be
manageable by contractors and site foremen it can be considered as successful. Making
sure the Method Statement is widely distributed will increase its positive impact. The
planning system also has a role to play in crayfish conservation and having the clear
guidance provided through the CAS project in the form of a Species Action Plan for native
crayfish provides all of the background, mitigation and compensation information required
to address crayfish needs in relevant areas.
9.6.
The CAS project does have a legacy to address and maintain. The establishment of a crayfish
database containing a large number of crayfish records should be added to by further
surveys. Each of the Ark sites will have to be subject to future monitoring to assess their
success in securing a strong and viable population of white clawed crayfish that is free from
the threat of NICS invasion. Public information on crayfish should be maintained where
possible and displays and leaflets should be continued to be used by Sheffield City Council
staff at public events. The public reaction to crayfish is surprisingly positive and this should
be built upon.
9.7.
The direct and in- kind support from Sheffield City Council should be recognised. The
importance of a reliable and stable base for the project officer cannot be overstressed.
Knowing that support, encouragement and assistance is at hand made the project officers
job less difficult and more enjoyable. Experienced staff colleagues who can access
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information, advice, and simple resources that could take a lone project worker
considerable time to collect, proved to be invaluable. Local knowledge also goes a long way
in smoothing the path and helping the CAS projects achieve more that it envisaged.
10.
The way forward
10.1.
The legacy of the CAS project is that it has created enough ideas to develop a further
project which would focus on identified priorities. This could run from April 2013 to March
2014 and look at maintaining areas of success through a firmer legacy of a long term survey
and monitoring programme. Further work on working with landowners in the riparian and
headwater areas of the Don tributaries could secure better land management in proximity
to water. Involving ‘Friend of’ groups in targeted habitat improvements could provide small
scale but locally important benefits to freshwater biodiversity. Organisations such as the
Environment Agency and Buglife can have a role in co-ordinating project networks.
10.2.
As stated above, moving a small project into catchment scale initiatives to conserve native
crayfish is considered to be a logical step up from the CAS project (P Bradley pers.com.)
Strategic initiatives in rivers management and areas of policy are important in gaining large
scale and long term benefits for native crayfish conservation. Survey and monitoring
should be maintained and extended into critical sites to track NICS movements.
Engagement with Yorkshire Water to investigate other Ark sites using reservoirs, catchment
action planning, and further work on barriers to invasion should be a priority. As well as
succeeding substantially in delivering the its aims and objectives, the CAS project has also
identified the large amount of work that still needs to be done locally, regionally and
nationally to secure a future for native white clawed crayfish.
References
Christmas M, (2009) England Biodiversity Strategy 2010 to 2015 Atlantic Steam or White Clawed Crayfish –
Autropotamobius pallipes. Environment Agency, Leeds, UK
Eades P, (2009) Crayfish in the Sheffield District, Environment Agency, Leeds, UK
Peay S, Guthrie N, Spees J, Nilsson E and Bradley P (2009). The impact of signal crayfish (Pacifastacus
leniusculus) on the recruitment of salmonid fish in a headwater stream in Yorkshire, England. Knowledge and
Management of Aquatic Ecosystems 394-395: 12. D 10.1051/kmae/2010003.
Peay S, (2011) Developing conservation strategy for white clawed crayfish at catchment scale in England and
Wales.- a way forward? In Rees .M, Nightingale J, Holdich DM, (eds.) Species Survival: Securing white clawed
crayfish in a changing environment. Proceedings of a conference held on 16th and 17th November 2010 in Bristol,
UK.
Peay S, Kindemba V, Attwood F, and Christmas M, (2011) A toolkit for developing catchment scale conservation
strategy for White clawed crayfish . Version 1 October 2011, Buglife The Invertebrate Conservation Trust,
Peterborough UK ISBN 978-1-908657-00-8
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