Summary response to Consultation re Hydro scheme approval, NIEA July 2011.

Summary response to Consultation re Hydro scheme approval, NIEA July 2011.

Brendan Kerr, Natural Living Assets. 

 This consultation is welcomed providing an opportunity to produce a sustainable solution to achieving renewable energy targets whilst at the same time incorporating a salmonoid management strategy for those rivers where salmonids have significant value.

An investor planning hydro power energy production may or may not be aware of the value of the salmon, sea trout and trout resource in the river. Salmon and sea trout can be considered as net energy contributors as they deliver biomass from the sea back to their river of origin. After 2/3 years of river growth from eggs deposited in gravel habitat they leave the river as smolts weighing a few ounces and return perhaps up to 20 lb weight  feeding well at sea.

Restoration and Enhancement beyond Conservation

Over the years the salmon and sea trout resource has generally been devalued due largely to their diminishing abundance, as a consequence of pollution, degraded habitat and in recent years, problems with survival during the sea phase of their life cycle. (see salmon life cycle Appendix 1). Given the survival issues at sea it is even more critical to ensure that the downstream seaward migrating juveniles survive and that the smolt run to sea is maximised. With all the attention that hydro schemes are currently getting as a means to achieve renewable energy targets it would be beneficial to have a salmon and sea trout strategy included as part of a holistic plan for particular hydro schemes. The hydro operator would gain indirectly form the good will generated and from contributing to enhanced fish runs and other monitoring opportunities.

Principles of Sustainability

Ecologically sustainable targets for the environment are just as important as hydro power targets. If hydro generating schemes are to produce sustainable clean energy then it will be essential to deliver sustainable objectives for the environment and ecological standards as well as sustainable energy production. Many approvals would add sustainable value if they also take account of ecological environmental quality standards to facilitate a viable and productive salmon and sea trout run. The specific river flow parameters set by NIEA for dewatered areas Q95, Q80, Q mean, for flow conditions go some way to meeting these needs but additional ecology parameters need to be defined including an integrated salmonoid management strategy to achieve improved salmonid stocks.

A recent guidance document “Protecting Fish : Guidelines for water Abstractors” from  DCAL provides excellent advice regarding mitigations to assist thriving fish populations and can contribute to useful mitigations such as upstream fish passes and downstream screens which will help to achieve salmonoid runs where there are hydro schemes.  

Opportunities for mitigation measures

There are excellent opportunities to conserve, protect and enhance the salmon and sea trout run whilst innovating in hydro power provided commitments are made to maximising salmonoid runs in appropriate rivers. There are many salmonoid rivers in NI that can have their salmon run improved. Mitigation measures would enable innovation and development to generate energy which also ensured a commitment to conserve and enhance salmon production in any particular river.

Environmental Monitoring

Any particular hydro scheme could double up as an environmental monitoring site to assess downstream smolt migration, upstream adult migration and as a site for continuous monitoring of other environmental indicators including, chemistry, hydrology flows, daily/ hourly fluctuations, oxygen demand, phosphates, nitrates and other pollutants.

Habitat Assessment

The opportunity lies in knowing the habitat of the river system in totality, and taking responsibility for a holistic river basin approach and identifying how each bit of the river contributes or can contribute in the future. A total catchment approach provided by the river basin management planning process of the water framework provides a useful framework. Each hydro scheme needs to be uniquely assessed for its impact on productive salmonid habitat and migration. DCAL and AFBI have carried out some excellent work on this using a Life Cycle Unit Assessment of salmonid rivers in NI This work needs to be fully developed and integrated into decision making so that best economic, socio economic and environmental decisions can be made.

Life Cycle Unit Assessment

There are three main classes of habitat for salmon and trout. Spawning, Nursery and Holding. Each of these has a vital role to play in the salmon’s life cycle. All three are needed and the absence of one will reduce the salmonid productivity of particular streams. The bank side vegetation and riparian zone also have a key role in enhancing the salmon and sea trout run.

Objective outcome,

Smolt migration is the optimum measure for productive salmonoid river habitats. Even relatively small streams with appropriate salmon habitat can produce significant runs of smolts to sea. The Life Cycle Unit Analysis can provide predictions for egg deposition, growth and survival through out the various life stages. Fish counters and fish passes at any hydro scheme would provide data on fish migrations essential to complete the life cycles and maximise output. Each river can be assessed and given a value as a natural smolt production unit. Where there is river habitat suitable to natural spawning, fish need to migrate upstream to complete the cycle of life.

Conservation Limits

The expected productivity of a salmonoid stream is currently assessed by applying conservation limits. It may be more useful to set a conservation target, or target for abundance relative to habitat. Since there is a strong desire to restore lost habitat it is likely that conservation targets could be revised upwards providing future improved value.

Even small short rivers with suitable habitat have the potential to produce significant numbers of sea going smolts (1 per meter of nursery habitat). For example the Bush currently accommodates an adult salmon run of 2000-5000 fish with current poor sea survival. Maximising the smolt run would therefore be a useful target for each river or stream. Sea survival of smolts to returning adults was about 35 % or so in the past and could return to that some time in the future.

Habitat Mitigation and Enhancement

Many rivers have lost their spawning gravel beds of the required structure to facilitate optimum salmon production. Though many still have excellent habitat and there have been some excellent works carried out in recent years by local angling clubs, rivers trusts etc., to improve suitable habitats there needs to be a commitment to maximising smolts relative to habitat. Nursery habitat may or may not be available to accommodate the spawning habitat. There may be little spawning habitat to fully utilise available nursery.

Where there is more nursery habitat than spawning habitat it may be appropriate to utilise a well run hatchery to provide the necessary abundance. Where there is ample spawning habitat it will be essential to ensure sufficient fish are able to spawn to maximise output.  A Short term, short sighted planning individual approach will favour compromised decision making without reflecting the potential for future production. A more innovate strategy would consider future potential for increased smolt production and habitat improvements. 

Small spattey rivers, ( ie rise and fall quickly, levels fluctuating with rainfall) can produce significant runs of salmon and sea trout such as those in Glens of Antrim, for example  perhaps up to 500or so and it would be socio economically and environmentally prudent to ensure this continued and was improved upon.

Role for Hatchery Fry Stocking.

An unfinished debate continues with regard to the role of hatcheries in enhancing salmon stocks. There may be scope to utilise a well run local hatchery using best practice stocking principles and salmon hatchery principles to maximise the smolt run to sea.

A well run hatchery requires, careful selection of genetic stock (endogenous) suitable for that particular river and stocking out sparsely to appropriate nursery habitat. This requires a few days of intense man hours to spread the small hatched fish (Alevins) in appropriate habitat so that survival is optimised. If carried out correctly fish are less likely to be washed away by flood events since they bury under the stones and weed for security. A hatchery can be very successful when used carefully to enhance production in a way best suited to local habitat considerations and will succeed where there is good local support and commitment to spread stock. Also when a hatchery is used in this way it is sensitive to the needs of any biodiversity objectives.

Hatchery Fry to enhance productivity

Whilst the topic of hatchery reared fish raises much debate there is good data to support the use of genetically appropriate stock and sparse stocking (1or 2 Alevins of fry / Sq m and certainly no more than 10/sqm) . Only appropriate nursery habitat should be stocked to ensure maximum productivity and efficient use of scarce resources.

Habitat Survey

Each river system above or below a proposed hydro will be unique and the starting point for the best sustainable outcome would be to fully survey the habitat of each river for its potential as a natural producer of salmon and sea trout and whether this should be utilised by hatchery origin fish. The decision to use hatchery fry or not, will depend on the availability of habitat and the commitment from any local community / angling groups to drive forward with support from DCAL, AFBI, DARD etc. Any threats to juvenile fish migration could be diminished by appropriate mitigation measures such as screens, fish by passes. Such investments can be structured to enhance recruitment from good habitat and maximise the runs of fish producing a long term positive investment   

Summary Points


Much of this response for salmonoid development strategy as part of Hyrdo development strategy could also be incorporated into other requirement for development of  biodiversity.

Role for Local communities

Many local angling clubs and local community organisations can work effectively with landowners to develop a holistic strategy that will ensure community support for local hydro schemes by working to enhance a salmon and sea trout as well.

Stakeholder Involvement

Continuous involvement of stakeholders and development of River Basin Management Approach incorporating a salmonoid development strategy in conjunction with a hydro development strategy would provide the most valuable sustainable outcome and greatest added value.


There is a clearly a need to communicate the value of salmon and sea trout and their wider value as an indicator species

Continuous Monitoring

Any new development in hydro would provide opportunities to enhance the salmon and sea trout run by utilizing appropriate mitigation measures and by providing monitoring of their impact.

Enhancement opportunities for increased recruitment of fish.

Opportunities for enhancement need to be investigated before approval and construction. Whilst this response is focused on salmon and sea trout other critical habitats need to considered in a similar way. When river habitats are utilized effectively there will be improved opportunities for excellent runs of fish. If river habitats are not developed, an opportunity may be missed and hydro schemes will be less likely to be truly sustainable.

Opportunity for synergy.

A well run hydro scheme committed to enhancing the salmon and sea trout in addition to generating energy would provide a useful resource for fish counts and monitoring upstream and downstream movements and could also monitor other environmental indicators.

Habitat Assessment

Salmon and sea trout need 3 main habitats, spawning, nursery and secure holding, habitat, for adult fish. Where there is a scarcity of spawning habitat this can either be developed via a natural spawning habitat development programme or if the nursery habitat is good enough stocking with small fish (Alevins) at density of 5-10 /sq meter is shown to maximise output of young salmon smolts.

All planning applications for hydro should take place in the context of habitat assessment and a plan to improve the productivity of suitable habitat.

Holistic Habitat Approach

Need to take a holistic habitat approach so that the optimum best sustainable option can be achieved. The management of the salmon and trout resource requires a holistic approach to catchment management in contrast to simply seeing water flow as a source of energy alone.

Fisheries Protection

Depending on the unique scenario for each proposal, appropriate salmonid fishery protection measures need to fully understood by the planners and investors. The Fisheries Act can provide for this but a more innovative approach beyond the scope of the Fisheries Act would deliver greater outcomes.

Economic analysis.   

More work needs to be carried out to assign the appropriate economic and environmental

value to ecological resources such as a recent DCAL report on Angling.

These iconic fish still “hang on” in many of our rivers and streams despite years of decline due to pollution, drainage and general decline of river habitat quality. The 1966 Fisheries Act established to protect salmon trout and eels will go some way to affording protections to these endangered populations despite past declines and almost total destruction of many populations. However this may need to be adapted to accommodate common sense measures that will improve environmental performance of Atlantic salmon and the more local sea trout.  Salmon and sea trout stocks have been under pressure from environmental degradations over many years though there are many recent success stories regarding re habilitation and improved runs, even where there are hydro schemes already established. Most damage occurred in a different age when there was

less awareness of environmental agenda and less knowledge regarding total sustainable solutions.

Given the interest and concern from the public for protection of the salmon and sea trout population all measures should be taken to ensure full protection is given to migratory fish movement downstream (fry, parr, smolts, kelts and upstream movements at the appropriate times). Local monitoring and awareness of the key factors responsible for encouraging fish movements need to be factored into any decision making process, Accommodating the need for enhanced salmon and sea trout runs would lead to a win win situation satisfying the demand for hydro power and by maximising the congruent protection and enhancement of salmon, sea trout and trout stocks.

Appendix 1

Brief Life History of salmon

Salmon eggs are laid in spawning gravel habitat of particular morphology and structure in the late autumn / winter by adult salmon of up to 20 lbs. average 4-5 lbs ( approx 400 eggs per pound female fish) Male fish will fertilize eggs as they are laid in dug out gravel beds called Redds.

In the spring depending on the weather and water temperature the eggs hatch out and stay in the gravel until they have grown a little and lost their yolk sac. They develop through

Alevins, fry, parr smolt over a few years in the stream and then to post smolts and mature adults in the sea where they become large fish.    

As they begin to feed they will move away ( mostly downstream of spawning site and gradually grow to about 7 cms in first year and to approx 15 cms in 2 year ( perhaps 3 depending on growth rate, ecology etc) As they grow they require more space and will compete for space so different habitats and stream morphologies come into play. Bigger fish needs a bigger territory and the fish need to be separated in suitable stony habitat as they grow larger.  

.Thus they will have a tendency to seek more suitable habitat and perhaps even swim upstream. There is a need for various habitats to support the different stages.  

Around early spring in 2/ 3./4 fourth year they go through a physiological change that prepares them for their seaward journey and for a life in the sea.

They migrate downstream and eventually enter the sea ( Smolt run)

They begin the ocean phase of their life and eventually follow their food source to feeding grounds of Greenland, Icelend, Norway.

After a year nor two at sea putting on massive weight they return mostly to their river of origin and migrate upstream. This can happen at any time of the year but tends to be from March through to October. An early fish that enters the river in March for example will find a place to hold up all the way through to winter or spawning time and will lay the eggs in gravel. Through out all this time in the river adult salmon need to survive droughts and floods taking security in pools ( Holding Habitat) and will conserve energy lying deep during droughts only moving during floods and other particular times. The main spawning run tends to occur later in the year where many fish both fresh from the sea and those that have been in the river will move upstream. A key factor in survival is that the fish can migrate up and down stream as required despite water flow impoundments.   

Brendan Kerr

Natural Living Assets 22 July 2011

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