Gyrodactylus salaris is a parasite which infects the skin, gills and fins of salmon, trout and some other types of freshwater fish. The parasite is less than a half millimetre in size, and is barely visible to the naked eye and can cause serious damage to some strains of Atlantic salmon. The parasite is very hardy and may be introduced by fishermen as it is capable of surviving for several days in damp conditions such as plastic bags, wet angling equipment and on the surface of dead fish.
Gyrodactylus salaris occurs naturally in the Baltic rivers of Finland and Russia, where the native fish are tolerant to the parasite and normally any infection causes them no harm. In areas where the parasite does not occur naturally, salmon trout and other freshwater fish have little or no tolerance.
In Norway between 1970 and 2002 salmon stocks on 44 rivers have been infected as a result of infection by Gyrodactylus salaris. Means to eradicate the parasite are very costly. The Norwegian remedial work is very destructive and this work has involved treating whole catchment areas.
At present the UK is free from this parasite, and in order to ensure that it remains so, a Working Group has been formed. This group will also look at the various ways in which the parasite can be contained and eradicated, should it ever appear in the UK. A news release giving notification of this was issued on 31 August 2005. http://www.scotland.gov.uk/News/Releases/2005/08/31142749
Further information and a leaflet on Gyrodactylus salaris can be found on the Scottish Government website at: http://www.scotland.gov.uk/Resource/Doc/1062/0000273.pdf and the Fisheries Research Service website which gives information on Gyrodactylus salaris at: http://www.frs-scotland.gov.uk/Delivery/standaloneM.aspx?contentid=861 and the FRS Code of Practice : http://www.frs-scotland.gov.uk/Uploads/Documents/CoPGyrod.pdf
Further information on the group and the minutes of these meetings are contained in the following pages.