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The Scottish Executive is taking seriously the threat of Gyrodactylus Salaris to salmon populations in this country. The Executive has asked the Atlantic Salmon Trust and the Association of Salmon Fisheries Boards to assist them in continuing work on this threat and a working group has been set up to consider further measures that could be taken at national and local level to prevent the disease from entering the country's rivers and lochs. They are talking about having strict policies in place, presumably regarding sterilising angling equipment being brought back into the country following angling trips abroad. Think this has nothing to do with canoeing? Well, as we pointed out in an article last year, our boats and wetsuits and shorty cags will have been in many of the same affected rivers in France, Norway etc. and a logical part of any plans would seek to extend control measures to anything brought back into the country that had been in an infected environment, and that is intended for subsequent use on Scottish rivers. We need to be prepared to take appropriate measures to prevent spread of infection, but also guard against calls to further restrict access to rivers on the basis of this threat. Gyrodactylus Salaris occurs originally in the Baltic, where fish have some natural immunity to it. It can survive several days in damp conditions (fishermens' waders, landing nets, lines etc) and reproduces very rapidly - even a single specimen could probably start an epidemic. The parasite has been detected in Russia, Finland, Sweden, Norway, Denmark, Germany, France, Spain & Portugal. GB & Ireland are free of the parasite - so far The only way to eradicate this parasite from infected rivers is to sacrifice the host species. Without the latter the parasite quickly disappears. The Norwegian method is to treat the infected rivers with rotenone. It is extremely toxic to most fish species and some invertebrates, while snails and freshwater mollusks are said to be only slightly affected. After so treating an infected river, it is restocked with clean, artificially-raised salmon and trout. So if you take your kayak (or open canoe, rubber dinghy, windsurfer, etc) abroad to Norway, Germany or France etc, what should you do on your return? The official recommended method is a minimum of ten minutes immersion in 1% Virkon/ 1% Wescodyne/ 0.2% sodium hydroxide or 3% sodium chloride. The concentration of salt in the sea is about 3%. So just go down to the sea and have an hour-long paddle, making sure to get everything thoroughly wet! The parasite is also killed by thorough drying out and/or heat; and it cannot survive away from salmon for more than about eight days. So if you are definitely not going to use your boat for two weeks you probably do not need to do anything else. But if you are going to go paddling in any river within the week, unless you get every part of your boat & equipment completely dry you might transfer the parasite. If so, when you paddle abroad & bring your gear back to the
UK, you must either |
