An over reaction is not necessary, but we think it is better to inform, rather than allow rumours to grow arms and legs.
It looks like we have a light infestation of Argulus foliaceus, again this is freshwater lice, it is a parasite, if the infestation goes unchecked, it can basically kill fish, light infestations are not uncommon, in stocked waters, also waters with heavy pike or perch populations, if it is left to spread and multiply the fish can become heavily invested, the following statement is the biology of the louse,
{The common fish louse lives in marine, brackish, and freshwater environments.[5] All life stages of both sexes are parasitic.[4] It attaches to its host, usually a fish, via its suction cups, pierces the skin with its sharp stylet, and feeds on blood.[5] It may live in the gills.[6] A heavy infestation causes inflammation of the skin, open haemorrhaging wounds, increased production of mucus, loss of scales, and corrosion of the fins. The wounds are often infected with bacteria and fungi, which further degrade the skin layers.[5] The fish can become anaemic. During feeding, the louse also injects digestive enzymes into the flesh. Infested fish may exhibit loss of appetite and slowed growth, and behavioural signs such as erratic swimming and rubbing up against aquarium walls.[6] The damage and infection cause stress and mortality.[7] }
At the Goldenloch we have had this threat hanging over us for 30+ years, ever since Lindores Loch, a very close neighbour, basically became one of the heaviest invested waters in Europe, eventually it was forced to close to trout fishing because of the lice infestation, recently being the last six or so years, various individuals, clubs groups have restocked Lindores Loch, for trout fishing, all failing and walking away from the Loch, this allowed the broken chain to reconnect, thus completing the cycle that has allowed the parasite to breed, I am pretty certain that the Argulus has again managed to multiply into vast numbers, as it can in warm water very quickly grow from thousands to billions, birds such as ducks, swans, Osprey etc spread it, but it needs fish to be the host, now fortunately there are some things that can be done and there are some remedies and things that can be done to reduce the infestation
Our bio security here is probably unrivalled and is the best there is, for 20 years we have operated disinfectant tubs, rinse nets and motors, which I must congratulate anglers for using, as pretty much 100% of clients use them, and it is vital that this continues, we have supplied nets for the same time, they are located around the loch at various points and we urge anglers to use our nets, Other lochs need to do likewise or they too will suffer this fate, so we have here a moderate infestation and today or rather tonight, 7 fish were closely examined, no lice were found, yet fish were caught at the weekend with Argulus attached but they very quickly fell off , at this stage these lice present no threat to the fish or humans, or the fishing, it is when the fish are severely infected which cause secondary infections, help us eradicate these fish, in each boat there will be Heavy Duty bin bags, if you think you have caught an infected fish, please bin it and tell us, if there a problem, at this moment in time no there isn’t, however Marine Scotland have been notified and we wait a reply, there are a few other infected waters around and anglers must declare or rinse there equipment in the disinfectant tanks as a dry net can have thousands of live eggs on it, remember the infected lochs in the 1990s were Lindores, Loch Fitty, being the worst, Argulus lives in pike, eels, or perch other smaller places were also infected however there were five key areas in Fife
Here simplified is the problem, the adult louse lay strings of eggs, thousands which are 0.01 mm in size, they are very sticky and attach themselves to anything i.e. a trout or an engine / electric motor / net / line / flies even when dried out they are still live eggs, transported to another water say equipment or birds feet they can very quickly attach themselves to another fish or even just the water and the next cycle begins, the louse get on the fish and as the fish go for cover on bright days the sticky eggs are rubbed off on vegetation awaiting hatching once that happens they swim around attaching themselves to a new host,
Disinfectant is the only way that anglers can combat this so dipping nets / equipment is vital, places without dip tanks just don’t get it or they don’t care, this is a problem that is here to stay and there are many places already infected that do very little to prevent further spread of Argulus, Please be aware and help to control this parasite its not going to go away. Proper approved disinfectant must be used as they contain the vital ingredients, jiff or pine just don’t cut it disinfecting now is really good as this is when the lice lay their eggs, but there are many other things that can be done that are much more succesfull,