ISA found in Wild Fish

In November 199 the Scottish Executive confirmed that for the first time the Infectious Salmon Anaemia (ISA) virus, though not the disease, had been found in wild fish. These were sea trout in the Inverie river (Lochaber) River Snizort (Skye) and Laxo Voe (Shetland), and also an eel in Loch Uisg (Mull). It was also found on the east coast in brown trout from the Rivers Conon and Eisaidh and Tweed, and rainbow trout in farms in Aberdeenshire and Kinross-shire.

The disease was also suspected on a further six salmon farms, bringing the total to 24. Eleven other sites have been declared infected so far. In the WRFT area sites in Lochbroom (Wester Ross Salmon) and Loch Kishorn (Norsk Hydro GSP) have been suspected but not confirmed.

Sea trout are known to carry the virus but it is not known whether they suffer from the disease. Nor is it clear if the original ISA outbreak originated from wild fish or if it was introduced from outside the country, and only then spread to wild fish. The Government announced in December that it was intensifying the ISA surveillance over a wider area, particularly in England and Wales. The WRFT has been assisting with the blood sampling of wild fish in the WRFT area.