Dying salmon on the Isla tayside

martinthomson

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I was absolutely shocked to see 4 dying salmon on the river isla last week. All 4 were along the south bank of the river,the last just before the croy at balbrogie. They had massive white patches all over them,and had no fear of me they were that far gone. I could have lifted 1 out of the water with my hand. I contacted david summers of the TDSFB but haven't heard back yet.
 

wrongfoot

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Have a read https://www.tweedfoundation.org.uk/FAQ_Diseased_Autumn_Salmon.pdf

The white fungus isn't UDN, rather a secondary infection. It could be caused by UDN in this case but it could also be environmental stress. It is interesting that warmer water with a resulting higher metabolism makes fungal attack less common. Presumably only up to a point though and it has been very warm...
 

martinthomson

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Have a read https://www.tweedfoundation.org.uk/FAQ_Diseased_Autumn_Salmon.pdf

The white fungus isn't UDN, rather a secondary infection. It could be caused by UDN in this case but it could also be environmental stress. It is interesting that warmer water with a resulting higher metabolism makes fungal attack less common. Presumably only up to a point though and it has been very warm...
Ahh brilliant.
Yes UDN. These 4 fish I saw ALL had gaping ulcers which were right into the deeper flesh of the fish, especially the head! I actually thought that a predator had been trying to attack the fish these wounds were SO bad. A couple of them had like holes in their ulcerated heads,and their tail fins were in a right old state,1 nearly losing its tail completely.
It was sad to see anglers out trying to catch fish when these fish were only feet away from them
 

aenoon

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Ulcerative dermal necrosis (UDN) occurs after migration into freshwater. Cause is not known, but is related to the non feeding activity of salmon, and pre spawning stress, excacerbated in low water flows.
Open lessions form, which can subsequently become infected with various fungal growths such as Saprolegnia, also referred to as cotton wool disease, which looks from your video these fish have.
Most salmon infected this way will die before spawning.
Might be best practise to remove them from the river.
regards
Bert
 

bobmiddlepoint

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Almost all cases of salmon with fungus aren't actually UDN. Many rivers will see a number of the spring fish get fungus while other rivers almost never see it. Stress, damage and water temperature all seem to be things that can lead to fungal infection.
These might be UDN as you say they have ulcers or it might be the new, first seen last year, red belly disease (cause unknown) which starts with a red rash or ulcers on the belly/lower fins/throat area which become infected with saprolegnia which kills the fish. Red belly has reappeared in some northern rivers this year (and probably elsewhere).

Fish with red belly rot from the underside upwards and these do look more like the normal fungus affected fish that turn up in many rivers in spring.


Andy
 

martinthomson

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I'm a trout guy and very rarely fish for salmon. But I can't understand why a guy can fish for salmon 20feet away from really sick fish.
Just wanted to ask you guys, wouldn't it put you off fishing at that particular river or at the very least, at that particular beat? If it were trout that were this sick, I'd be giving the river a break. At least until the rain came and the water levels started to rise a bit so more fish came up river no?
 

bobmiddlepoint

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I'm a trout guy and very rarely fish for salmon. But I can't understand why a guy can fish for salmon 20feet away from really sick fish.
Just wanted to ask you guys, wouldn't it put you off fishing at that particular river or at the very least, at that particular beat? If it were trout that were this sick, I'd be giving the river a break. At least until the rain came and the water levels started to rise a bit so more fish came up river no?
It sort of depends on the scale of the problem. A handful of fish with fungus is nothing out of the ordinary on many rivers in the spring/early summer. If everyone stopped fishing every time there were a few mouldy salmon seen some rivers would hardly ever open. Finding a few wouldn't put me off fishing.
A major outbreak with dozens or hundreds dying is another matter and it wouldn't be something I'd be prepared to fish through.


Andy
 

Laxdale

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The Isla fish is just a normal fungi fish. The Isla/Ericht has them every year just like the N Esk.
However, a mate seen a few of the red belly fish on the main Tay, middle river, in early May (Just before a decent rise cleared them out).
 

liphooked

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It's very sad to see The Salmon with The Disease there was a video on U-tube about Wild Salmon in Canada catching A disease which was traced back to The Farmed Salmon Industry which was covered up as some prominent people had interests in The Farms.
The Pacific Salmon in Alaska look to have a similar Mould/Decay after Spawning
 

aenoon

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It's very sad to see The Salmon with The Disease there was a video on U-tube about Wild Salmon in Canada catching A disease which was traced back to The Farmed Salmon Industry which was covered up as some prominent people had interests in The Farms.
The Pacific Salmon in Alaska look to have a similar Mould/Decay after Spawning
All pacific salmon die after spawning, the growth of fungus on their spent bodies is part of same process.
It has absolutely nothing to do with Salmon Farming.
regards
Bert
 
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