SARF041: Developing practical strategies for reducing the spread of harmful organisms during the transportation of live fish

Start Date: 1st April 2008
End Date: 31st March 2009
Main Contractor(s): University of Stirling
Other Sponsor(s): BTA

Objectives

1. Obtain necessary licences and permissions to hold live crayfish, discharge chemicals and conduct animal experimentation.

2. Review of existing transport procedures and examine options for physical water treatmen

3. Conduct laboratory trials for efficacy and safety of potential chemical water treatments. .

4. Develop and test pilot strategies on small scale fish transport.

5. Commercial scale trial for safety of treatments.

6. Produce a briefing note, which will be referred to in the BTA Code of Practice, and prepare manuscripts.

Summary

The UK trout industry routinely moves live fish throughout England, Wales and Scotland. The British Trout Association (BTA) has suggested that the majority of the 50 million+ trout grown each year in the UK are moved at least once in their life. With the transportation of live fish there is a risk of spreading non-native crayfish and other aquatic animal pathogens. Both the UK trout industry and government wish to minimise this risk. The purpose of this project is to provide the UK trout industry with practical strategies for reducing the risk of transferring potentially harmful and environmentally damaging organisms during transportation of live fish. This problem has been identified as a research priority by the BTA and has been highlighted in a recent report on crayfish in Scottish waters commissioned by Scottish Natural Heritage (SNH)1. The potentially harmful organisms considered in this application are fish pathogens and crayfish. Fish pathogens in transport water Fish pathogens may be present in the water used to transport live fish and as a consequence may be introduced to the recipient farms. Any such pathogens would most likely also be present in or on the fish and it is likely that the treatment of transport water would not necessarily protect the recipient of the fish against infection. Prophylactic treatments are an option for addressing this problem but are not permitted under the current BTA Code of Practice2. However, in some cases transport water is exchanged at sites other than that of the final recipient of the fish. For example during lengthy transports water may be exchanged, the old water is discharged and replaced with fresh water. In this case ensuring that the water is free from significant pathogens could reduce the risk of accidental spread of infection. Crayfish Crayfish are non-native animals in Scotland with the potential to have a significant detrimental effect on ecosystems, biodiversity and the physical structure of Scotland's inland water. In particular the signal crayfish, Pacifastacus leniusculus, is a highly invasive species and accidental translocation of this species during the movement of live fish is thought to be one means by which it can spread1. Ensuring that there are no live crayfish in transport water prior to water release could significantly reduce this risk of further spread of this species.