[Hamish Young]

The water is very low and water temperature has increased dramatically over last few weeks, maybe this has contributed to the recent condition of some trout??

Absolutely, yes.

[Andy Finlay]

not sure if anyone has noticed but there is a road being built pretty close by, not saying it's the cause obviously.

[Ali Mcewan]

I have a good friend who is very up on his fish diseases etc..
I forwarded the photos & spoke to him on the phone to see what he thought..

It looks either bacterial or viral,
He sees colminarus (sp) in fish quite a bit, it's naturally occurring in most body's of water & signs start around the fishes mouth, as in Scott's photo..
A bacterial infection is the best we can hope for as it's harder to spread & easier for the fish to fight, were as a viral infection will spread like wild fire & is ver hard for a fish to fight off..
These things are usually triggered by either
Unusual water temps
Large water temp fluctuations
Issues with water chemistry
Or worst of all some idiot introducing fish into the river from a unknown source ..

He's offered to send up swab kits so he can get cultures grown off them to see if & what bacteria it is.  These need to be done sterile ie no hand , ground contact etc.. But I'm sure the fishery board will be onto this as quick..

The person who he thinks is the at the top of such issues is out the country till Wednesday, but has forward photos to them to see what they think, il let you know the reply in due course..👍

[Gordon Dempsey]

Great work Alimac. As well as swabs would it be beneficial to have tissue samples too? I guess any fish caught in this condition should be put out of their misery so any amount of tissue could be collected from the affected parts.

[Mike Barrio]

Jim said that if an angler does get a very fresh one, could they bag it and freeze it please, so he can then get it collected.

It can then be taken to Marine Scotland to be examined.

[Ali Mcewan]

We discussed skin scrapes too look at under the microscope, but it's unlikley to be a parasitic problem & if it was, the said parasites would die during transit..
Viruses could be checked, but this needs blood taken from a live fish..
He also echoed earlier talk of being very careful with flys nets, hands etc that come into contact with fish, even if no visual signs are seen..

[Mike Thornton]

Jim Kerr will probably get Jamie Urquhart, the Dee/Don Board biologist, to chase all these things up.

[Kev Graham]

Jees, this is a worry and sad to see infected fish like that .  With salmon numbers on the Don having a hard time these days, this is all we need with our Browns.  Perhaps not panic stations yet, but I sincerely hope i dont come across any fish displaying any of these signs.  Geographical spread of the infected fish on the Don needs understood. I will pass on details of this thread, and cross contamination measures to any angler i meet out there.

KG

[Ali Mcewan]

Jim said that if an angler does get a very fresh one, could they bag it and freeze it please, so he can then get it collected
It can then be taken to Marine Scotland to be examined.

Jim..
Has marine scotland said they can do much with a frozen fish? Just because as far as I'm aware once a fish is frozen it kills all the things you'd be looking to test, or bacteria, fungus etc  so basically renders it useless for testing.. 
Id think this will require some good fishermen, a biologist & a day on the river to get any sort of definite results..

[Derek Roxborough]

Sounds as though it could be Saprolegnia, a fungal disease, usually on salmon,could be caused by Costia feeding on the slime and destroying the protective coating, we used to see it in a hatchery I worked at,one treatment, if I remember right was Malachite Green to kill the fungus and the costia , it's now banned,
easgach1

[Gordon Dempsey]

Saprolegnia is an opportunistic fungus that will grow on absolutely anything in water, the furry stuff that grows on uneaten fish food in tanks for example is Saprolegnia. It only attacks fish where there is something exposed and unprotected such as, like you said,  slime removal in the case of a Costia infestation or where there has been a physical injury, and cannot attack a healthy fish. The presence of Saprolegnia is therefore a symptom of an ailment but not an ailment in itself. I believe methylene blue may still be a component of current preparations to get rid of it although I do remember malachite green in the dim and distant past and how it stained the silicone in tanks forever!

I am fairly certain that my fish didn't have any Saprolegnia growing on the affected parts which suggests to me that whatever happened happened quickly because a Saprolegnia secondary infection is virtually inevitable when bare flesh is exposed.

[Gordon Dempsey]

This article about UDN makes very interesting reading. Perhaps it is significant that all the affected fish reported so far have been large - the article states that juvenile fish are generally not affected by UDN and also explains the part played by Saprolegnia. There is also a photo in the article that looks a bit familiar.

http://flyfishing.co.uk/news/news/6396-deadly-wild-salmon-disease-found-in-river-spey-fish.html

[Duncan McRae]

Guys

Wish I'd noticed this post earlier.
Had a couple of Trout last night off Ardmurdo and both had a very small patch of fungus on their snouts.They weighed around 2lb and 1lb respectively.Didn't think much of it and returned them.
Last week a couple of Anglers at Ardmurdo had to give up their evening fishing as there was so much raw sewage floating down the water.Presumably from Inverurie sewage plant.
Could this be a factor?

Duncan

[Jim Kerr]

To all

I have had consultation  with  Aberdeen Fish health inspector from Marine Scotland today advising , that if any angler catches a Trout that is on the verge of dyeing or very badly diseased, could they keep the fish alive in their landing net and phone 01330 830080  it can then be collected at the river bank alive if possible.

With Thanks
Jim Kerr
Senior Fishery Officer
Don DSFB

[Rob Brownfield]

It is interesting that there does indeed appear to be an issue with an unidentified disease/bacterial infection, yet the river is still open for angling.

With the close proximity of the Dee, Ythan and Deveron, I would have thought the sensible measure wound be to stop angling, get the problem identified, and then, if not serious, carry on as normal, or if infectious, you have already put in preventative measure.

Yes it would pee people off, but we could have a potential time bomb about to wipe out our rivers, yet we are still allowed to fish. If it proves to be a false alarm, then we have lost a few weeks fishing....