Policy Areas

Aquaculture

Fish Farm. Image by Alan Wells

Farmed salmon production has increased rapidly in the West Highlands and Islands of Scotland. There are a number of significant concerns with regard to the sustainability of the salmon aquaculture industry in Scotland, including the release of harmful chemicals, benthic impacts due to organic enrichment from waste food and faeces and the sustainability of food sources. However, the most significant concerns for wild fish interests are the potential negative effects of sea lice and escapes.

Sea lice: A number of reviews have considered the effects of interactions between salmon farms and wild salmonids (e.g. Revie et al. 2009). There is now compelling scientific evidence that sea lice emanating from salmon farms have the potential to pose a very serious risk to wild migratory salmonid populations
Escapes: Farm escapees (from both cages in freshwater and marine cages) have the potential to interbreed with wild fish. Scottish salmon have unique genetic lineage specific to each river system (and sometimes unique to individual tributaries). Cross-bred offspring are less fit for survival at sea thereby putting the wild population at risk. In addition, escaped juvenile fish in freshwater may out-compete wild fish prior to migration and can develop to sexual maturity as parr, interbreeding with adult returning fish

ASFB provides guidance to Boards/Trusts with regard to the aquaculture planning process, including the current Audit and Review Process set up to transfer aquaculture operations from Crown Estate development consents to planning consent under the Town and Country Planning Act. In addition, ASFB plays a central role in working with Government, Parliament, Local Authority Planners, Marine Scotland Science, SEPA and SNH in an attempt to ensure that the industry operates in a manner compatible with the needs of wild salmonids.

ASFB sit on the Ministerial Group on Aquaculture and are involved in various working groups as part of that process. ASFB are also playing a key role in the Scottish Government’s ‘Managing Interactions’ programme.

The Scottish Government have, with the agreement of Scotland’s wild fish organisations and salmon farming industry, set up a facilitated discussion process to support the development of a positive way ahead for both sectors. The ultimate aim of this process is to maximise the benefits to Scotland from the contributions of wild fish and the aquaculture industry. Our initial input to this process, which is coordinated with RAFTS, S&TA, Fish Legal and AST, is set out in the briefing below.

ASFB continues to work with the other key organisations in the wild fisheries and environmental sector with the shared aim of protecting wild populations of salmon and sea trout from the environmental consequences of aquaculture.

Beaver Reintroductions

Beaver dam in Perthshire. Photo: Bob Laughton

There is a great deal of interest in the licensed trial reintroduction of European beavers in Knapdale, Argyll. This has inspired discussion and debate about future reintroduction of beavers to Scotland. Fishery interests in Scotland hold concerns about the potential effect of beavers on migratory fish, principally due to construction of dams which could impede fish movement. In light of these concerns, the Beaver/Salmon Working Group was set up to consider the issues surrounding beavers and migratory fish.

ASFB is a member of the Group which is presently examining the potential impacts of beavers on salmon habitat and how these might be modelled to gain a better understanding. The Group, which is chaired by Professor Roger Wheater, comprises a range of experts on fish, beavers and general ecology.

Climate Change

Earth - Image by NASA

Climate change has been identified as a threat to Atlantic salmon. The species’ developmental rate is directly related to water temperature, and increasing temperature in freshwater may result in smolts developing more rapidly and entering the ocean at a suboptimal time in relation to their planktonic food sources.

In addition, as air temperatures warm, much of the snow that feeds the river systems is expected to melt earlier. This will lead to a reduction in the flow of many rivers in the spring and summer, which will increase water temperatures further and may reduce the overall optimal habitat available to the Atlantic salmon.

The effects of climate change on river ecosystems are now becoming apparent. River temperatures have increased over the last 20–30 years in upland Scotland by up to 1°C per decade in ways that reflect global trends in air temperature.

The first priority in mitigating these effects is to control atmospheric concentrations of greenhouse gases. However, with further climate change inevitable in the short to medium term, attention is now focusing on the development of accommodation and adaptation strategies, through which adverse effects on species or ecosystems can be minimized. Some of the key needs with respect to developing adaptation strategies for rivers and their biodiversity were summarised by Ormerod (2009 – Aquatic Conserv: Mar. Freshw. Ecosyst. 19: 609–613):

1. To quantify and predict the direct effects of climate change on species distribution, population processes, life cycles, community composition, species interactions and ecological processes.

2. To assess which river ecosystems are most vulnerable to climate change: for example alpine, montane, lowland or urban.

3. To minimize the adverse effects on river biodiversity of actions taken to mitigate climate change, for example large-scale hydropower development or land-use change for biofuels and carbon sequestration.

4. To control stressors that will exacerbate climate-change effects.

5. To buffer rivers against temperature gain. At least in climatic zones that have riparian trees as natural ecosystem features, the restoration of riparian zones appears to be an effective mechanism for offsetting the highest temperatures and creating thermal refuges. The benefits from effective riparian management are multiple; for example from energy flow, sediment control, nutrient retention and habitat enhancement (Larsen et al., 2009).

6. To increase resilience or resistance to climate change in rivers and their associated ecosystems. There are likely to be conservation benefits in restoring water retention in catchment soils; restoring functional linkages among catchments, riparian zones, floodplains and rivers; and making integrated land–water conservation a reality.

It is clear that survival of salmon and sea trout during their marine migration phase has fallen over the last 40 years. Some of this reduced survival can be explained by changes in sea surface temperature and subsequent contraction of feeding grounds. These issues can only be addressed by controlling atmospheric concentrations of greenhouse gases and as highlighted in point 4 above, a key strategy for managing adaptation of species sensitive to climate change is to minimise additional pressures such as those which are man- induced.

In the specific case of Atlantic salmon and sea trout, this involves concentrating on those factors which fishery managers and the Scottish Government can address. These include the improvement of degraded freshwater habitat, removal of barriers to migration, reduction in exploitation where necessary – including mixed stock fisheries, ensuring marine and terrestrial renewables are deployed in an environmentally sensitive and well-informed manner and addressing the negative effects of salmon farming.

In Scotland, individual DSFBs promote conservation policies appropriate to individual rivers. In 2010, the overall catch and release rate for salmon was 70%, rising to 86% for spring salmon. In addition, ASFB is working with Marine Scotland in the development of a Climate Change Adaptation Plan for Scotland, working to minimise and mitigate the potential negative consequences of fish farming and marine renewables and seeking to reduce exploitation in mixed stock fisheries (where such action is necessary to conserve threatened stocks).

Diffuse Pollution

Run-off from agriculture (Cattie burn) - Image Dee DSFB

Diffuse pollution is the release of potential pollutants from a range of activities that individually may have no effect on the water environment, but at the scale of a catchment can have a significant impact (i.e. reduction in water quality, decrease in wildlife, etc.). Diffuse sources of pollution include run-off from roads, houses and commercial areas, run-off from farmland, and seepage into groundwater from developed landscapes of all kinds.

Diffuse pollution from land use activities has a significant impact on water quality. To achieve the objectives of the Water Framework Directive (WFD), the quality of Scotland’s water environment must be maintained and, where necessary, improved.

Rural diffuse pollution arises from land use activities such as livestock grazing, cultivation of land to grow crops and from forestry operations. Such activities can give rise to a release of potential pollutants the pressures and impacts of which include: eutrophication; loss of biodiversity; silting of fish spawning grounds; and impacts on human health through drinking water or bathing water pollution. The pollutants of concern include the nutrients nitrogen and phosphorus, sediment, pesticides, biodegradable substances, ammonia and micro-organisms.

ASFB is a member of the Diffuse Pollution Management Advisory Group, a partnership that focuses on improving Scotland’s water environment by reducing rural diffuse pollution. The main purpose of this advisory group is to: help create a robust governance, decision-making and coordination framework for the effective delivery of rural diffuse pollution RBMP actions in Scotland; and ensure input from a cross section of rural, environmental and biodiversity interests.

DPMAG have developed a two tiered strategy approach to reduce diffuse pollution in Scotland:

a national campaign to prevent water bodies from deterioration in status and make improvement where they are not far from a status boundary. DPMAG has developed a national awareness campaign to support the national campaign;
a targeted approach in catchments where the extent of diffuse pollution problem on the water environment requires a more focused approach. Fourteen priority catchments have been selected for the first RBMP cycle.

A major output from DPMAG is the rural diffuse pollution plan for Scotland which is designed to ensure that the key stakeholders in Scotland work in a coordinated way to reduce diffuse pollution from rural sources.

Fish Movement/Stocking

Alevins – Image courtesy of P Minting

DSFBs are statutory regulators and written consent must be obtained from the relevant Board prior to the artificial stocking of salmon and sea trout in the Board’s district. ASFB, in conjunction with RAFTS, have produced guidelines to assist Boards in this regulatory function; hatcheries and restocking projects can be effective management actions if carried out in the appropriate circumstances. Inappropriate stocking practice can be ineffective and costly at best, and at worst positively damaging to native stocks and sub-stocks of salmon. This is becoming more evident as our understanding deepens in relation to the genetic structures of salmon. The guidelines are designed to assist Boards in the decision making process.

Gyrodactylus salaris (GS)

More information on GS can be found here.

Hydro Electricity

River Cuaich (Spey Fishery Board). Image by Paul Kemp

The first large hydro-electric scheme in Scotland was built in the 1890s. The establishment of the North of Scotland Hydro-electric Board in 1943 led to a succession of new schemes in the following 30 years. Many of these major hydro schemes were built before the full ecological impact was understood and at a time when methods to resolve the problems were poorly developed. There is currently a renewed interest in hydro-electric power, arising from Government incentives to achieve a higher proportion of energy from renewable sources.

The effect of a hydro-electric scheme on fish depends on the site, the type of scheme, and the design, construction and operation of its various elements. There are four main types: run of river; storage;
pump-storage; and catchment transfer. The potential effects on fish are:

Barriers to migration and access to spawning grounds
Physical damage from turbines
Pollution
Transfer of water between catchments
Other changes in hydrology

Generators of electricity are required to, “avoid, so far as possible, causing injury to fisheries or to the stocks of fish in any waters” (Schedule 9 of the Electricity Act 1989).

Obstructions: Weirs and impounding dams may obstruct the passage of salmon or other fish unless an effective fish pass is provided. Temporary obstructions may also occur during the construction of a scheme (e.g. building of coffer dams or culverts on temporary roads) and the needs of fish must be considered.

Turbines and tailrace: Depending on the design of a turbine, fish passing through it may be killed or injured from changes in pressure or by being struck by turbine blades. It may therefore be necessary to provide screens at the intake to keep fish out. Screens may also be necessary at the downstream end of a tailrace to prevent fish entering it.

Pollution: Fish may be adversely affected by pollution arising during the construction and operation of a scheme.

Catchment transfer: As well as the hydrological effects of catchment transfer, fish can gain access to previously uninhabited watercourses via the tunnel used to transfer water. This could potentially lead to the transfer of water-borne infection. Salmon are thought to recognize chemical attractants in their home waters, so catchment transfer also has the potential to mislead fish up a ‘wrong’ tributary.

Changes in hydrology: Hydro-electric schemes change the hydrology within the area of the development, and, in cases of catchment transfer, beyond it. These changes include:

In run of river schemes there is usually a large reduction of flow in the river channel between the water intake and the discharge from the power station. This may also occur downstream from the impounding dam of a storage scheme. If a sufficient residual flow is not provided, the stocks of fish in these areas will be lost or significantly reduced and the passage of migratory salmon will be prevented. A required residual flow is usually called a ‘compensation flow’.
If a stretch of river is dammed, the resulting reservoir may destroy fish spawning grounds or nursery areas. In storage schemes, depending on the pattern of generation, the flow downstream of the power station may fluctuate markedly and this could adversely affect fish or fisheries. The water level in the reservoir may also fluctuate, affecting fish stocks.
Catchment transfers can result in substantial changes in flow in the affected catchments with consequential effects on fish or fisheries.
There are other indirect effects, such as changes in sediment transport which can alter the character of a river bed, which in turn may affect fish stocks.

ASFB have established a specific working group to address the issues surrounding hydro-electricity production. ASFB will continue to work at a strategic level, in order to influence the prioritisation of the CAR-license review process towards ensuring free passage of wild salmonids and ensuring that adequate compensation flows are provided to allow fish to migrate through the river.

SEPA run of river hydro guidance (pdf)

Invasive non-native species

More information on invasive non-native species can be found here.

More information on the ‘check, clean, dry‘ campaign can be found here.

Marine Planning

The Marine (Scotland) Act 2010 introduced, for the first time, a marine planning system in Scotland. The planning system will be based on three tiers:

A UK-wide Marine policy statement
A national marine plan
Regional marine plans

The marine planning system will set out the Scottish Ministers policies for the sustainable development of the Scottish Marine Area. The planning system will also contribute to marine conservation via the Scottish Government’s 3-pillar approach to marine nature conservation. It is therefore important to ensure that the plans take appropriate account of the protection of wild salmonids, especially with regard to aquaculture, marine renewables and mixed stock fisheries.

ASFB has responded to the National Marine Plan pre-consultation, and continues to work with officials across Marine Scotland to ensure that the final National Marine Plan is compatible with the needs of wild salmonids.

Marine Renewables

Offshore wind turbine. Image by Calum Duncan, MCS

The Scottish Government is committed to the development of a successful marine renewable energy industry in Scotland. It has committed to meeting a stated target of 50% of Scotland’s electricity demand from renewable sources by 2020. Last year the Sustainable Development Commission undertook a comprehensive study of Tidal Power in the UK. The study found that tidal stream technology could provide 5% of the UK’s electricity – 58% of this potential is around the Pentland Firth in Scotland. However, there are significant uncertainties as to the environmental effects of marine renewable devices due to the large number of different, novel devices under development. The Scottish Government and Renewables Industry therefore propose to adopt a survey, deploy and monitor approach. The main concerns with regard to the effects of marine renewables on migratory salmonids are the effects of noise during construction and operation and the effects of electro-magnetic fields (EMFs) during operation and from associated cabling. The potential effects of EMFs and sub-sea noise on migratory salmonids must be considered in the light of the considerable uncertainties regarding the behaviour and migratory routes of these fish.

ASFB is working with Marine Scotland, Marine Scotland Science, SNH and the renewables industry to find the best way to fill these knowledge gaps in order that proper assessments of the potential impacts of proposed schemes on wild salmonids can be made.

Mixed Stock Fisheries

Montrose Nets. Image by Alan Wells.

Mixed Stock Fisheries (MSFs) are defined by the North Atlantic Salmon Conservation Organisation (NASCO) as fisheries that exploit a significant number of salmon from two or more river stocks. Whilst mixed stock fisheries are not inherently detrimental to stock status (any fishery, single stock or mixed stock, only poses a problem if it exploits stocks where there is no exploitable surplus) without knowing how many fish come from which rivers it is not possible to know the impact of the catch on individual catchments or to apply targeted conservation measures in the fisheries to protect individual catchments. Mixed stock fisheries are therefore considered by all interested northern hemisphere countries to present particular difficulties for management and species conservation.

Focus Area Reports (FARs) on the measures being taken by each jurisdiction to implement NASCO’s agreements have now been completed. The FARs have been reviewed and the review group’s findings for Scotland included the following statements:

‘The FAR provides some information on a proposed method for using catch data to assess stock status in the absence of CLs, but the Group notes that it is unclear whether this approach is being used and whether it provides a reliable reference point for satisfactory stock status. A strategy is being developed for the management of mixed-stock fisheries, but at present there is no clear policy. The Group is concerned that these fisheries are still being operated despite a lack of information to characterise the exploited stocks. These issues are not consistent with the NASCO agreements and guidelines and need additional actions.

Carcass Tagging
A carcass tagging scheme has been in operation in England and Wales since January 2009 . Any salmon and sea trout caught by means other than rod and line (i.e. by licensed net or trap) must be tagged with a uniquely numbered Environment Agency carcass tag. This must be attached immediately after capture and remain attached until the fish is processed. Details of the fish and the tag reference numbers must be recorded in an annual log-book (supplied) and returned to the Environment Agency at the end of the year. Similar schemes have been in operation in the Republic of Ireland since 2001 and Northern Ireland since 2002. Carcass tagging has been considered both as a quality control measure and as a means to minimise the possibility of illegally caught fish reaching markets or dealers. In combination with the ban on sale of rod caught fish across the UK, any untagged fish would be made unmarketable and clearly identifiable as illegally taken.

ASFB have established a specific working group to address the issues surrounding mixed stock fisheries. We continue to work with Marine Scotland in an attempt to develop a positive solution to some of the issues surrounding, in particular, exploitation of the fragile spring stock component where such action is warranted. ASFB also coordinated the recent application by Scotland’s District Salmon Fishery Boards to Scottish Ministers for compulsory carcass tagging of all wild net-caught salmon and sea trout. The proposal is for a mandatory, uniquely numbered scheme for all wild salmon and sea trout offered for sale.

Predation

Cormorant – Image Stuart Brabbs

A variety of birds and animals can cause serious damage to fisheries. The law recognises this and permits licences to be granted to control piscivorous birds and seals. Licences to shoot seals are granted under the Marine (Scotland) Act 2010. Control of piscivorous birds is determined under the Wildlife and Countryside Act 1981.

Crucial to granting of a licence to control piscivorous birds is the gathering of evidence to demonstrate ‘serious damage’ with which to support licence applications. ASFB supports its member Boards in the collection of the relevant evidence. Experience shows that predation can be particularly high at certain times, for example during the seaward migration of smolts in Spring. By this stage, young salmon preparing for the marine environment have left their natal streams and are effectively ‘irreplaceable’. It is important therefore that predation ‘bottlenecks’ such as these can be dealt with through appropriate, evidence based licensing.

Wind farm Developments

‘Wind Turbine – Image Stuart Brabbs

Scotland is now facing an unprecedented number of terrestrial windfarm development applications as the Scottish Government strives to meet renewables targets. By their very nature these developments will occur in freshwater catchments and some of them will have the potential to impact sensitive parts of river catchments for migratory and non-migratory fish species. Most wind farm developments are now large scale industrial projects often taking place in fragile upland landscapes and ecologies that require a full assessment of the risks associated with such projects. Not only do the turbine bases require a considerable amount of excavation but there also tends to be extensive road building and river crossings required to build and service wind farm developments. Risks associated with such projects include:

Impacts on hydrology and habitat during construction due to large scale excavation in fragile habitats
Extensive road building with accompany culverting, drainage, run off and sedimentation issues
Possible long term impacts on the hydrology in the catchment
Impacts on fish behaviour relating to turbine movement
Impacts relating to transit of high voltage cabling

Large scale terrestrial wind farms have been built in important river catchments with little or no observable impact on either water quality, quantity or fish populations. Equally, there are have been examples of catastrophic failure of wind farm developments (Derry Bran – Republic of Ireland) and also significant water quality impacts during construction – particularly during periods of high run off. There is therefore potential for considerable long and short term damage to the freshwater environment. By deploying a proper risk assessment, appropriate construction methods and good contractor supervision, these risks can be reduced to manageable levels.

ASFB Wind Farm Policy (Apr 2009) (pdf)