AST Response to Natural Resources Wales Consultation on Salmon Stocking
I attach the response form to this consultation on behalf of the Atlantic Salmon
Trust. The AST is a UK based charity which seeks to encourage scientific and other
research into all aspects of salmon and sea trout biology, conservation and
management, to disseminate the results of research and to influence policy makers,
managers and the public to base the conservation and management of salmon and
sea trout on scientific and other evidence.
In November the AST and the IBIS interreg project organised a conference on
salmon stocking. The conference examined the potential role of stocking in
restoring, sustaining and enhancing salmon populations and fisheries, bringing
together experts on salmon science and management - including those with direct
experience of stocking -, anglers, and fishery managers. It considered the different
types of stocking, the effectiveness of stocking as a means of increasing numbers of
returning adults, the impact of stocking on the productivity and genetic integrity of
salmon populations and the cost-effectiveness of stocking as a management
measure. While the conference itself did not seek to reach conclusions, in our view
the presentations and cases studies clearly demonstrated:
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That stocking is rarely effective as a means of increasing significantly
numbers of returning adults;
In the longer term, sustained stocking over a period of years is likely to reduce
the fitness, and hence productivity, of salmon populations;
Stocking is only cost-effective in exceptional conditions (for example, salmon
ranching in Iceland).
There may, nevertheless, be occasions when stocking is justifiable, and
provided managers are clear about what they are seeking to achieve, and
about the costs and the risks involved, stocking should not be ruled out as
management measure if other options have been exhausted.
These conclusions seem consistent with the recommendations of the review, which
in principle we support, subject to the detailed comments in our response. Details of
the
stocking
conference
can
be
found
at
http://www.atlanticsalmontrust.org/blogs/stocking-conference-in-glasgow.html.
I should add that we are surprised that the review does not refer to the NASCO
Stock Rebuilding Protocols. These clearly outline the steps which should be taken to
identify the causes and nature of any stock decline and to establish the requirement
for a stocking programme. They advise that the exact reasons for the stock decline
may be unknown, but possible causes and potential threats should be described and
evaluated. References to these are included at the end of our response.
Ivor Llewelyn
Director (England and Wales)
Atlantic Salmon Trust
A consultation on NRW’s salmon stocking, third party
salmon stocking and the future of NRW’s hatcheries
Q1. Do you agree or disagree with the definition of effectiveness used for the review
and with the conclusion that there is little evidence available to demonstrate that
mitigation and enhancement stocking is effective? If you believe you have evidence,
please provide it.
AST agrees that the policy of NRW should, in principle, be geared towards maintaining the fitness of
salmon populations, thereby maximising the number of fish. It should also seek to preserve the
adaptive life history characteristics of each population and avoid reduction in genetic diversity within
and among populations, these aspects being important for the continued survival of the species
under changing environmental conditions.
Only if there are problems that cannot be overcome through habitat and other environmental
restoration should the last resort of stocking with the offspring of native (same population) salmon
be considered. In this case genetic and other guidelines as to obtaining broodstock, carrying out
crosses, rearing conditions and stocking out should be followed meticulously (e.g. NASCO stock guide
lines – see bibliography below) to reduce the risk of damage to the wild stocks. Failure to do so can
result in fewer fish being produced than if the broodstock had been left to reproduce naturally.
.
We agree that there is little evidence in the great majority of cases that stocking
programmes have led to any long term increase in productivity; while stocking can
(but often does not) produce a temporary increase in the number of adults returning
to a river, it is likely in the longer term to lead to a reduction in productivity.
We also believe that effectiveness should be considered in terms of cost –
effectiveness, and in particular in terms of opportunities foregone. NRW has limited
resources to devote to salmon and sea trout conservation, and these need to be
spent in the ways that deliver the greatest conservation benefit. These are unlikely
to include stocking
Q2: Do you agree or disagree that there is enough evidence available to influence a
substantial change to NRW’s existing salmon stocking activity?
Agree. Research work and management experience across a wide range of different
salmonid species and over many decades, clearly indicates that the establishment of
hatchery programmes should only be considered when the need for such
programmes has been clearly established and the risks associated with such
programmes minimised. The vast majority of research shows that when released into
the wild, hatchery reared salmonids have lower survival than wild juveniles of the
same age. Those that do survive often have poor homing ability and less success in
reproducing. Such shortfalls are thought to be the result of hatchery practices (small
number of broodstock, forced matings, insufficient crossings, artificial diet, lack of
natural selection, and so on) which can lead to behavioural defects, domestication,
inbreeding and a loss of genetic diversity in the receiving wild population
Q3: Do you agree or disagree with our interpretation of the Habitats Directive as it
may apply to all our own and third party salmon stocking on rivers designated under
this legislation?
Agree.
Q4. Do you agree or disagree that mitigation and enhancement stocking are not
consistent with an Ecosystem Approach?
In our view it is necessary to distinguish between enhancement and mitigation
stocking.
We agree that enhancement stocking is not consistent with the Ecosystem
approach, in that if resources devoted to stocking were used for habitat improvement
the benefits would be to the ecosystem as a whole, and not simply to salmon.
In our view mitigation stocking needs to be considered on a case by case basis. In
many cases habitat improvement will be the most effective mitigation strategy.
However, where there is a substantial loss of spawning habitat, and the impact of
this cannot be mitigated by habitat improvement elsewhere in the catchment, there
may be a case for mitigation stocking with fish bred from broodstock taken from the
wild elsewhere in the catchment.. This would not be contrary to the ecosystem
approach, since the damage being mitigated would be exclusively to migratory fish.
In such a case stocking should take the form of supportive breeding. Supportive
breeding involves capturing a fraction of a wild population, breeding the fish in
captivity and releasing their progeny back into their native habitat to mix with the wild
segment of the same population. All of the broodstock is obtained from the wild
each year. There is now a wealth of evidence clearly indicating that the risks
involved in supportive breeding schemes are substantial and these must be
minimised by adherence to strict guidance and stocking protocols. However, in some
circumstances such actions are justifiable and It is the AST’s strongly held view that
no other form of salmonid stocking should be considered to enhance wild stocks,
unless the wild population in a system is effectively extinct.
We do therefore accept that river specific, stocking programmes may be undertaken to:
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Mitigate the partial loss of a stock due to manmade factors such as hydroelectric
dams
For investigative reasons
As a component of an historic statutory/legal obligation.
__________________
Q5 .Do you agree or disagree that it would be more cost effective for NRW to
improve habitats and thereby secure further reductions in mortality of wild fish as an
alternative form of mitigation to stocking?
Agree that in most cases habitat improvements, including barrier removal, will be the
most cost- effective of utilising resources provided for mitigation, but, as indicated
above, this needs to be considered on a case by case basis.
Q6. Do you agree or disagree with the recommendation that NRW should bring all
our own mitigation and enhancement stocking in Wales to an end and work with
others to end all salmon stocking in Wales? What would you regard as a practical
timetable for achieving this? Should we include sea trout in this recommendation?
Agree so far as enhancement stocking is concerned, and in principle on mitigation
stocking, subject to the points made above. Sea trout stocking should be included,
and the changes should be introduced as soon as is feasible.
Q7. Do you agree or disagree that NRW should focus its efforts and resources on
improvements to habitat? What mitigation and enhancement measures would you
suggest NRW and partners adopt as an alternative to stocking?
Agree. Particular attention should be paid to reducing, and wherever possible
removing, barriers to migration. This is important for downstream migration of smolts
as well as for upstream migration of adults. Recent studies on the Tweed, for
example, have shown very high levels of mortality from predation around barriers (up
to 50% in low flow conditions) and delays to smolt migration, as well as exposing
them to increased predation, may also reduce their ability to adapt to saltwater. Flow
regimes are also important for both upstream and downstream migration, and the
need to ensure adequate flows during migration periods should be taken into
account in abstraction regimes on salmon and sea trout rivers.
Q8. Do you agree or disagree that NRW should reduce its hatchery capacity and
investigate the feasibility of adapting the Cynrig facility to develop a broad-based
freshwater and fisheries research facility for Wales, in partnership with other
interested bodies? We would particularly welcome suggestions from relevant
organisations about potential collaboration opportunities at Cynrig.
We would welcome a well designed research facility in Wales. However, it is
essential that the facility is linked from the outset to a carefully thought out and
funded research programme, properly co-ordinated with other research being carried
out on migratory salmonids. The AST would be happy to be involved in the
development of such a programme; it would be particularly appropriate for Cynrig to
specialise in research into sea trout, following up the Celtic Sea Trout Project.
Bibliography and weblinks:
NASCO
Fisheries Management Guidelines
http://www.nasco.int/pdf/far_fisheries/Fisheries%20Guidelines%20Brochure.pdf
Habitat Protection and Restoration
Guidelines http://www.nasco.int/pdf/far_habitat/Habitat%20Guidelines%20Brochure.pdf
Aquaculture, Introductions and Transfers and Transgenics (including stocking guidelines)
http://www.nasco.int/pdf/agreements/williamsburg.pdf
Guidelines on Stock Rebuilding Programmes
http://www.nasco.int/pdf/agreements/stockrebuilding.pdf
Environment Agency
Operation Instruction Leaflet: Schemes to stock rivers with salmon. sea trout and brown trout from
locally sourced broodstock
http://www.wyeuskfoundation.org/issues/downloads/EA%20Stocking%20Policy.pdf
Agri-Food and Biosciences Institute, Northern Ireland
Transfer and stocking of freshwater fish. Review and Advisory report for the Loughs Agency (need
weblink or full ref? )
Institute of Fisheries Management
Code of Good Practice for Freshwater Fisheries Management.
http://www.ifm.org.uk/sites/default/files/page/Fishery%20Management%20COGP_1.pdf
Prof Andy Ferguson – letter on genetics of stocked trout. Fly Fishing and Fly Tying Magazine
(http://www.flyfishing-and-flytying.co.uk/) - March 2014.