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Study to identify ways of reducing farmed fish fin damage in hatcheries. - AW1209

A key priority of Defra is to “support and develop British farming and encourage sustainable food production.” The UK’s fish-farming industry is largely a success story. It is an important contributor to the national economy, a key employer in rural areas, and the main provider of oily fish to UK consumers. However, the sustainability of the industry has been challenged on two aspects – environmental impacts and the welfare of stocks.

Despite progress in addressing many welfare concerns, fin damage is an issue that has persisted in both the salmon and trout sectors. Injury to fins is thought to cause pain and damage to live tissue and its supporting skeletal structure. Fin damage may also compromise swimming and provide a foothold for disease causing organisms.

Our previous Defra-funded research (classified as “outstanding” by the external review) has demonstrated that all UK farmed trout suffer fin damage: the fins on an average fish are reduced by at least 25% from their natural length. Fin damage is similarly ubiquitous in farmed salmon, although the severity is less well documented. This welfare issue affects a very large number of animals with UK hatcheries incubating around 135 million salmon and trout eggs each year.

The recent research on fin damage in UK trout targeted the final stages of production, and suggested various potential control strategies. However, the gathered evidence demonstrated that fin damage starts earlier in the production cycle in salmon and trout, and that these earlier stages (fry/parr) should be the prime target for reducing the problem. The UK’s Farm Animal Welfare Committee has endorsed the approach of tackling fin damage at its initiation.

This proposal brings together researchers (with experience and the necessary skills) with farmers (both salmon and trout, and producer organisations) and the dominant welfare certification scheme (RSPCA Freedom Food). The project will build upon our previous research in this area (funded by Defra, EU and others) with the latest tools and understanding. We are confident we can produce a better understanding of fin damage and help farmers develop practical strategies to reduce the problem of fin damage. The project will consist of 5 main parts:
1. We will quantify fin damage on freshwater salmon farms and collect relevant information on husbandry factors. This will provide an objective assessment of the current state of the problem, the range of industry practices, and highlight risk factors that might contribute to fin damage;
2. We will then conduct laboratory trials to allow us to understand the time delays between injury and the appearance of observable fin damage, and for recovery from damage;
3. We will develop non-invasive methods to more accurately monitor fin damage and aggression on commercial farms;
4. With the understanding and methods developed in the first three parts, we will monitor fish on commercial farms over time to identify the circumstances that contribute most to fin damage;
5. Finally, we will bring farmers and stakeholders together in a workshop to discuss the findings and develop practical on-farm strategies.
Develop and apply measures of fin damage to freshwater salmon to assess the extent of the problem, its development, and variability within the industry

Develop and apply simple measures of aggression on commercial sites to assess the variability within the freshwater salmon sector and association with the level of fin damage

Determine the risk factors (environmental factors and episodic events) that increase aggression and fin damage in freshwater salmon populations
Propose practical strategies that will reduce aggression and fin damage during commercial production of salmon and trout
Project Documents
• EVID4 - Final project report : AW 1209 evid4 V2   (1392k)
• ANX - Annex : Appendix 4 part A   (634k)
• ANX - Annex : Appendix 1 part A   (187k)
• ANX - Annex : Appendix 2   (498k)
• ANX - Annex : Appendix 3   (12618k)
• ANX - Annex : Appendix 5   (5057k)
• ANX - Annex : Appendix 6   (565k)
Time-Scale and Cost
From: 2012

To: 2016

Cost: £515,919
Contractor / Funded Organisations
Silsoe Livestock Systems Ltd, University of Stirling, C E F A S (CEFAS), University of Bristol
Animal Welfare              
Fields of Study
Animal Welfare