HC Deb 13 November 1989 vol 160 cc59-60W
Mr. Dalyell

To ask the Secretary of State for Scotland what assessment he has made of ctenolabrus rupestris, the gold sinny wrasse, as the alternative to pesticides as a means of removing sea lice from salmon in fish farms; and if he will make a statement.

Mr. Lang

The possible use of gold sinny wrasse to control sea lice infestation in farmed salmon is being investigated in trials by the Institute of Fishery Technology Research in Norway and in Scotland by the Sea Fish Industry Authority's sea farming unit in conjunction with the salmon farming industry. Preliminary results in aquarium observations and small-scale field trials with wrasse taken from the wild suggest that numbers of sea lice on farmed salmon are reduced in enclosures shared by wrasse.

The viability of this method for large-scale and long-term control of sea lice is uncertain as yet. Sea cage trials are still at a relatively early stage but the results of current work will be of considerable interest.

Investigation of other possible alternative controls on sea lice is also in progress. In particular, the Scottish Salmon Growers Association have commissioned the Institute of Aquaculture at the university of Stirling to investigate alternative treatment methods and the Department of Agriculture and Fisheries for Scotland is co-ordinating a large-scale project, part-funded by the European Communities research programme into possible development of a vaccine treatment. It is not possible to say if or when positive results or practical methods of treatment might emerge from these investigations.