SARF021: Development of practical 'on-farm' cod welfare indices

Start Date: 01/03/2006
End Date: 28/02/2008
Main Contractor(s): SARF, Defra
Other Sponsor(s): Johnson Seafarms Ltd

Objectives

1) Undertake a replicated pilot study of a current crowding and pre-harvest handling procedure to apply and investigate an initial set of welfare indicators and to establish the level of variability in key physiological, environmental and behavioural parameters, so that subsequent experiments take account of this.

2. Organise a preliminary workshop on cod welfare. This workshop will appraise the findings of the pilot study so as to develop an agreed set of welfare indicators for investigation in the later replicated main trials and revise the sampling protocol if required.

3. Run a series of replicated trials during commercial harvests that will further investigate and validate the chosen welfare indicators (derived through assessment of the results of the pilot study and the initial workshop), so that they are the most valuable to the industry.

4. Produce and present a report of cod welfare indices and in addition, recommended pre-harvest handling protocols to the industry by the end of 2007.

5. Organise a final workshop. The final workshop will disseminate the results of the whole project to the wider industry and other interested parties

Summary

This study will take advantage of direct access to a large cod on-growing facility by undertaking on-farm trials of direct relevance to full-scale commercial practices. It is our opinion that tank based studies should be avoided in this context since their relevance to commercial practices is often questionable. Tank based trials often involve subjection of fish to artificial levels of discomfort that raise stress responses for the deliberate assessment of responses. The value of this approach for our proposed studies would be questionable as the purpose of this study is to develop indices from existing knowledge, and many reactions of fish, including cod, to stressors are generic. This is particularly true in relation to the proposed detailed assessment of pre- harvest handling. Furthermore, such stress inducing experimentation would go against both the ethos of JSF and the 3Rs principles of SARF itself. By conducting an initial pilot study of a commercial pre-harvest handling procedure using the sampling and analysis techniques proposed for the later main replicated trials, parameters that are indicative of fish welfare will be measured and recorded. Where necessary the results from this pilot study will be used to refine the sampling protocol in later replicated pre-harvest handling trials. Here we plan to investigate the effect of introduced variables that are perceived to improve current procedures with respect to welfare, and consider the practicality and economic implications of doing so alongside their actual measured benefits