I have often heard/read that it is only a very low percentage of stocked brown trout that survive the winter in rivers. The quoted survival rates can be as low as 1%

Can anyone confirm, or challenge, these low percentages through research carried out in his club water?

Many thanks

GF

I will challenge them!!

we had a visit this week from Tim Jacklin of the wild trout trust, His assesment wasnt as grim as yours!

They had researched somewhere and I am sure he said that 5% had survived! what an investment!!

I have plugged it before but Nick Gilles book on trout is a good read on this and the efects of stocking.
Or if you want to find out more email a question to Tim Jacklin at the wild trout trust.

Thank you WP. I will refer to the sources you are mentioning above.

In any event, it seems that reported numbers generally seem to be lower than 10%, but was wondering if there are significant deviations between fisheries, e.g. trout introduced in freestone rivers vs. chalkstreams, strains of trout etc.

I have no stats, but would be truly amazed if less than 10% survive.

Assume 50% are caught, 10% predated and 10% migrate or move between fisheries, that's still 30% that are in any river. If 250 fish are stocked iin a season, that's 75 fish. if half of these die, there would be 37 dead fish washed up on each stocking of 250. Seems high to me?

Then be truly amazed.
Quite simply you stock them at a weight achieved in false conditions,stock ponds, with survival priority and growth achieved by behaviour unsuitablle to life in a river system.
They lose weight on the whole during the summer as they cannot sustain that condition in a less protein rich enviroment. they weaken and drop back.They have learnt the wrong life lessons to survive in the flow. By the time the winter conditions comes they are not equiped to deal with the conditions.
The figures are there and avialable, They are quite shocking, and you can dispute them all you like. However the figures are not anecdotal, but based on field tests. By people qualified to do such trials.
sad thing is by stocking them where there is a natural population you are also increasing the stress and problems with the residents.

Don't know enough about it to agree or disagree - although as both a biologist (albeit years ago) and keen amateur naturalist (mostly birds and verging to the ornithological end of the birding spectrum) I'd have to say I understand the principles underlying what you say. The one thing I know about the beats I currently fish is that my own club doesn't know and has been attempting to find out what happens to stocked browns. Can you point me to any of the field trials you cite?
Thanks in anticipation.
GD-

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We come from dust; we return to dust. I'm going to fish

I'm not a scientist, but I have talked to many and read heaps on this subject. I have personal interest in a stocked/wild stream.
On a recent thread some one asked me to sum up what Nick Giles writes much better in his book.( The Nature of Trout, by Nick Giles, published by Perca Press).
About wild trout and in one section the effects of stock fish on the population, which in turn helps explain this, quite frankly shameful figure.
I first heard it about 5 years ago from Vaughn Lewis on an advisory visit and frankly was appalled at the waste of fish and club funds.
I believe he was talking from experience. However Tim Jacklin was talking about actual research carried out into the mortality rates.And he confimed that it is very low. I will try and cotact him to put the actual figure up.

If you want to read the Post that I wrote on this:- Why stock rainbows?
I would re-post it here,but I think that would seem a little egotistical, and I would hate to taint a very important issue with the kind of personal comments its likely to attract.

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I see the science behind this, and being a 'big fish' man, i am well aware of fish 'going back' after stocking, but only if they're unsuitable for the water in question, surely? Stick a 7 pounder in a chalkstream and itll lose weight, but would you have the same problem with a 1lb fish.? I also don't subscribe to their not being able to deal with the winter flows as this can be learned in the summer. Look, i don't know anything about this, and am just playing devil's advocate, but i just don't believe such a small % can survive. a far larger proportion survive in stillwater, and i think it's int he WTT and other similar group's interest to perhaps minimise the stocked fish's chances...

how about some references to some legitimate peer reviewed scientific publications, without that it is nothing more than anecdotal

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...''i think it's in the WTT and other similar group's interest to perhaps minimise the stocked fish's chances''.

The Wild Trout Trust dont have a vested interest and twist the figures to reduce the chances of stocked fish''. I have seen plenty of research from facilites, that have no vested interest in any other methodology than to get to the bottom of how things work. The wild trout trust publiches this research, invites these scientist to talk at WTT functions, and makes policy based on these findings

With all due respect you don't understand the science, You understand what you see as the logic of the situation. But its not actually the way it works. Size doesn't come into it, The same rules of stress and loss of condition is across the board.(even with stocked fish of a few ounces).
They simply cant re-learn in a summer, the behaviour patterns they survived with and developed from egg to fry to parr in a totally alien environment.

Honestly I used to see it the same way. My interest is to keep stocks up in our stream. And the catch records up.
I liked the idea of the wild trout waters, but I didn't think it was relevant to our stocking policy. Its just a case of having plenty of rising trout for the members.

The only way we where told, that we could keep stocked fish in condition in our brook was to feed them pellets which frankly would have not just been practical, and would have resulted in some exceedingly fat Chub!
Really read the book, or at least my clumsy attempt to sumarise it and you will understand a little more.