The return of perch disease?

[tiddlertamer]

There was an article today in the Angling Times about the discovery of 10,000 mainly two inch dead perch in an intake between Farnmoor reservoir in Oxford and the river Thames.

 

Fears are growing that this discovery heralds the return of virus which decimated perch stocks back in the 1970s and 1980s.

 

Anglers Net aficionado and regular contributor, who is also one of three founder members of ‘The Perchfishers’ Steve Burke, was quoted in the article.

Steve, who was also a co editor of ‘The Book of the Perch’ said: “that it could be the same disease...”

He spoke of two main causes: “the aeromonas bacteria...thought to be spread by seabirds, and a nematode worm, the tell tale signs of which are tail rot and ulcers... and that there hasn’t been a national epidemic since the mid 1980’s.”

He went on to say: “that when it strikes, between 90 per cent and 100 per cent of the water are wiped out.”

 

Others sounded more cautious and the EA is examining water samples.

Nonetheless, it sounds very ominous. Anyone know anymore about this potentially worrying disease and incident?

Edited November 17, 2009 by tiddlertamer

[Anderoo]

There was a topic about it here:

 

http://www.anglersnet.co.uk/forums/Thousan...d-t2214778.html

 

We're waiting to hear what the EA have to say. It sounds like a localised incident, and probably pollution-related, but no-one knows yet. If it is perch disease, it's extremely bad news, but the fact that the AT are spreading scare stories before they have any facts makes me feel better!

[tiddlertamer]

If it is perch disease, it's extremely bad news, but the fact that the AT are spreading scare stories before they have any facts makes me feel better!

 

Hi Anderoo

 

I'm sure we all hope it's an isolated pollution incident.

 

Nonetheless, a very well respected perch expert has expressed fears it could be the perch virus that caused so much damage to the species.

 

So let’s not necessarily knock the Angling Times.

 

Perhaps there is a journalist at the Angling Times with his own agenda about getting the story he wants and is willing to trick an expert into giving him the quote he wants to 'prove' his article. But that sounds a touch disingenuous.

 

So accusing the Angling Times about 'scare stories' may be a touch unfair. The quotes are from one of the UK's leading perch experts.

 

Journalists may have their own agenda sometimes (or their editors) but they don’t make up the quotes which form the bulk of their copy. (Well they often mangle the odd quote but not normally maliciously...)

 

If I was a journalist, it would be the perch experts that hang out here that I'd be seeking out for a quote or background information.

[chevin]

I remember the perch problem of the '70s quite well as it hit just about every water in Britain. However, the odd thing was that I did not see any dead perch on the fisheries that used to produce so many of them for me. What was even stranger though was their return was sudden and straight away we were catching perch of respecatble sizes where, just a few weeks earlier, we were catching none. The phenomenon was discussed pretty widely and indeed, I discussed with anglers such as Dick Walker and F.J. Taylor after being the first among us to suddenly begin to catch perch again on the uppper Ouse. I hope that whatever is happening isn't so wide spread this time, but if it is, I hope that someone is able to make sense of it all.

[Leon Roskilly]

However, the odd thing was that I did not see any dead perch on the fisheries that used to produce so many of them for me.

 

 

I believe that 'perch disease' is actually a combination of two factors.

 

Firstly the perch are infected with a parasite that weakens their immune system, but doesn't kill them.

 

Then the weakened perch become infected with a bacteria or virus which wouldn't normally kill them, but because of the infection they already carry, now does.

 

And it is this second infection that decides upon what happens next.

 

In one outbreak, all the dead perch floated, but in another they all sank to the bottom so that there was no sign of dead perch.

 

But I remember reading of a diver coming across banks of dead perch piled up in the depths of a resevoir.

 

I hope that it hasn't returned, the perch fishing was really starting to be good.

[Anderoo]

I haven't read the article, but just took it from the “that it could be the same disease...” quote - it could be, but it could equally be many other things. As I said, if it is the dreaded perch disease, it's extremely bad news, speaking as something of a perch fanatic and an angler very local to this incident.

 

Unless the AT have data or information that we don't, I consider this nothing more than speculation. I have a great deal of respect for Steve and I don't think he's been tricked or has said an aything other than - well, it might be!

 

I'm a 'wait and see' kind of person, and I'm afraid the fact that the AT has run a story on this based around the most serious and senasational outcome doesn't surprise me, but maybe I'm getting too cynical in my old age!

 

If I've misunderstood and Steve is saying that perch disease is the most likely cause of this type of terrible incident, I am both apologetic and very saddened. That is the worst possible outcome.

[Steve Walker]

It would be good to hear from Steve directly - I mean there is more than one conversation those quotes could have come from, and it's not clear whether Steve suggested it or the reporter asked about it.

 

You know how newspapers are, answering "well, yes, I suppose it could be bubonic plague, but we've not had a case since the 14th century" becomes "Black Death Might Kill Us All says expert!"

[Anderoo]

I just spoke to Steve. He says hi to everyone, he is still lurking but has been so busy lately that he hasn't had time to post much.

 

On the perch incident, he told me that he stressed to the AT journalist that it could be any number of things (one of which could be the infamous perch disease) and feels that he may have been slightly misquoted. However, he hasn't seen the article yet. To be clear, he wasn't suggesting that in this incident perch disease is the most likely cause of the fish deaths.

 

I'm not sure if it's been mentioned yet, but other species did make up a small part of the fatalities, although perch made up the majority of deaths. I know that part of the Thames quite well, and perch are the predominant species, so that needs to be bourne in mind.

[gozzer]

I too remember the 'perch' disease that chevin mentioned, and wondering what exactly happened. Yeadon Tarn near Leeds had a massive head of perch, and they disappeared seemingly overnight, without any visible trace.

 

This report from what I've read, doesn't seem the same. If reports are correct, they say approx 10,000 fish, mainly small perch. That could mean that 2 or 3 thousand could be other species, so whatever caused it is not exclusive to perch.

The EA must be puzzled, because they hoped to have an answer by Friday morning, so unless some are privy to extra info' it's just speculation on the part of the AT. I doubt it would be the first time that they have taken a 'quote' from an expert out of context.

 

John.

 

Cross posting with Andrew. Glad Steve's OK and still looking in.

Edited November 18, 2009 by gozzer

[Steve Walker]

If there were other species mixed in it seems far more likely to have been a pollution or even a natural event. Deoxygenation of a backwater somewhere, perhaps? Minor pollution incident on a shallow sidestream? It's not uncommon in my experience to find bits of river containing very little but small perch, particularly where the water quality is a bit dubious in the first place.