COMPULSORY CATCH AND RELEASE

[williegunn]

Just a thought, but the Deveron and the Spey are close neighbours, the Spey run starts early in the season and has a very low autumn element, the Deveron has its main run in October.
Why ?
If genetics does not matter surely these two rivers seperated by a few miles would be the same.

[wilbert]

Posted by Willie Gunn on Today at 8:19am
Just a thought, but the Deveron and the Spey are close neighbours, the Spey run starts early in the season and has a very low autumn element, the Deveron has its main run in October.
Why ?
If genetics does not matter surely these two rivers separated by a few miles would be the same.

Dont know the answer to this one, but the Deveron fish seen to have evolved a little smarter, why spend all year in the river when you can swim up at the last minute shoot your muck then bugger off again?

It would be interesting to see if you put Deveron Fish in the Spey and vice versa if you would get good runs all year round. A little Victorian in my thinking but who says its wrong?

[dunbar]

Just a couple of brief points about the Tyne. I am neither for or against stocking, it has its place as one of many management tools at a fishery managers disposal. The box of tools will include many other items, including C&R.

I think it is generally accepted stocking is of greatest value where there is a need to rehabilitate a river, for example the Tyne. Where there has been a catastrophic problem, ie pollution.

- It is reckoned that the Tyne is still to reach its full capacity of spawning stock, and it is still on this upward projectory despite the closure of the hatchery.

- why have the sea trout stocks increased in parallel with the salmon stocks, despite virtually no sea trout stocking?

- Surely the greatest bottleneck in the Tyne was the horrendous estuarial pollution - of course the hatchery will have kick started the recovery progress but the massive estuarial clean up simply cannot be pushed conveniently away from the equation.

Why is the Clyde stock regenerting despite no stocking? Exactly same situation as the Tyne.

Why does the Tweed not need to rely on hatcheries?

Why unnecessarily remove healthy fish from the spawning beds and 'soften' the progeny by putting them under artificial conditions, thus reducing their ability to cope in the wild?

Sorry for digressing away from the main focus of this thread, but there are too many imponderables to simply say hatcheries are the answer to everything.

[charlieh]

dunbar said:

Just a couple of brief points about the Tyne. I am neither for or against stocking, it has its place as one of many management tools at a fishery managers disposal. The box of tools will include many other items, including C&R.

I think it is generally accepted stocking is of greatest value where there is a need to rehabilitate a river, for example the Tyne. Where there has been a catastrophic problem, ie pollution.

- It is reckoned that the Tyne is still to reach its full capacity of spawning stock, and it is still on this upward projectory despite the closure of the hatchery.

- why have the sea trout stocks increased in parallel with the salmon stocks, despite virtually no sea trout stocking?

- Surely the greatest bottleneck in the Tyne was the horrendous estuarial pollution - of course the hatchery will have kick started the recovery progress but the massive estuarial clean up simply cannot be pushed conveniently away from the equation.

Why is the Clyde stock regenerting despite no stocking? Exactly same situation as the Tyne.

Why does the Tweed not need to rely on hatcheries?

Why unnecessarily remove healthy fish from the spawning beds and 'soften' the progeny by putting them under artificial conditions, thus reducing their ability to cope in the wild?

Sorry for digressing away from the main focus of this thread, but there are too many imponderables to simply say hatcheries are the answer to everything.

I very much agree. It's also worth looking at the story of the Wye - I don't have the book with me, but H A Gilbert's 'Tale of a Wye Fisherman' describes how that river recovered from being netted to a point where rod fishing was almost useless, to being the best river in England and Wales, in the space of 20-30 years around the turn of the last century. There may have been a little pump priming, but this regeneration was essentially achieved without artificial help.

It's true to say that marine survival rates were much higher then, so the recovery would have taken fewer generations than now. Also, river conditions were probably better, with no sheep dip issues, the banks cleared and fenced (as the Wye & Usk Foundation is trying to do now) etc.

Nevertheless, it goes to show how a river can recover largely on its own. And this is why I support the work of the W&UF in sorting out the habitat issues, in spite of the endless barrage of pro-hatchery stuff from Geoff Franks et al.

[para1]

bobrobert said:

Sainsbury's get them from a fish farm, not wild fish but bread in captivity and living in a cage offshore, fed shite and swimming in it.

I would rather eat someone else's toe nails

All of them? I mean the fish that Sainsbury's stock

You must be a food critic of great experience.
The reason I say this is, one of the food programmes the wife watches had to make a meal for the Queen.
To cut a long story short, Richard Corrigan an Irish chef, coudn't get his organic salmon for the the finals and had to use farmed fish.
None of the 3 judges had a clue that it was farmed fish and he won his round with three judges praising him.
The thing that puzzled me at the time was on the first round eliminator he said he would only use "organic" salmon and not wild fish as he said they were in decline and wanted to preserve them.
How more organic can you get on than a wild fish?

[charlieh]

para1 said:

The thing that puzzled me at the time was on the first round eliminator he said he would only use "organic" salmon and not wild fish as he said they were in decline and wanted to preserve them.
How more organic can you get on than a wild fish?

In fact, wild fish is not eligible for the organic label as governed by the Soil Association. Something of an anomaly, perhaps, but that's the fact.

Corrigan did a television programme last year in which he was filmed singing the praises of organic farmed salmon from the salmon farms situated by Clare Island in Co Mayo. Ask anyone who fishes the Bunowen, Belclare or Newport rivers, or Loughs Furnace and Feeagh, all of which discharge into Clew Bay, what has happened to the sea trout since that farm was put there. It's a joke to suggest that organic salmon farms are less damaging to wild fish.

If you want to eat salmon, consider the fresh pacific salmon that is available in an increasing number of supermarkets. It comes from an MSC certified fishery - in other words, it is sustainable.

[para1]

Charlie H,
thanks for that info on organic salmon.

[woodcockandsewin]

When we are left in a state of listening to "THE SOIL ASSOCIATION" telling us what is and isn't organic salmon, it's time to use your 15 footer as a pole vault and ask the Clangers their opinion.

With respect,

The Iron Chicken.

[Tyne Angler]

Alan

Alleged stocking stats from Kielder hatchery for 2005:

1. Salmon stocking
A salmon stocking programme began on the Tyne in 1981 to compensate for the loss
of spawning area brought about by the construction of Kielder Reservoir. This
involves stocking a minimum of 160,000 hatchery-reared juvenile salmon into the
river and its tributaries each year. Stocking has since been extended, first to mitigate
for losses in the estuary arising from poor water quality during dry summers and
second, as a precautionary measure for any impacts of the second Tyne Tunnel
construction.
The fish are stocked either as 0+ (young of the year) in the autumn or 1+ (overwintered)
fish in the spring. Areas with good nursery habitat but supporting relatively
low densities of wild juvenile salmon, as determined from electrofishing fisheries
survey data, are selected as stocking locations.
560,000 hatchery-reared juvenile salmon were stocked into the Tyne catchment in
2005. Table 4 details the number of salmon stocked at each stocking location.
Table 4. Stockings from the Kielder Hatchery in 2005
Location Spring Autumn
1+ 0+
North Tyne 30,000 135,000
River Rede 10,000 85,000
Kielder Burn 10,000 40,000
South Tyne 30,000 110,000
Main Tyne 30,000 80,000
Total 110,000 450,000

Data taken from www.environment-agency.gov.uk/commondata/acrobat/tyne_report_2005_1675381.pdf

The salmon rod catch returns graph on the above document also makes interesting reading, showing the catches beginning to show an improvement from the late 1970's early 1980's.

[castlikeaghille]

dunbar said:

- why have the sea trout stocks increased in parallel with the salmon stocks, despite virtually no sea trout stocking?


Why is the Clyde stock regenerting despite no stocking? Exactly same situation as the Tyne.

Why does the Tweed not need to rely on hatcheries?

A thoughtful post. In response to three of your points:

1. Aside from the kick start Springer has pointed out, Sea Trout stocks will usually recover quickly naturally if spawning habitat is improved and where there is minimal competition from adult salmon (as on the Tyne). Even now, by all reports, the Tyne is below its critical mass of spawning adult salmon. An adult sea trout will typically spawn annually anywhere from 4 - 9 times after two/three years old; very few adult salmon will spawn more than once, and only once they are at least 4 and usually 5 years old.

2. Yes a few fish are trickling back to the Clyde, but I suggest it is hardly a parallel with the Tyne recovery from a few hundred rod caught fish in 1980 to 4000+ now

3. The Tweed catches are going backward at a rate of knots (do not be fooled by all the 15,000 a year most productive river in Europe hype - that is a highly dubious use of stats - the underlying trends are poor). No river in Scotland is more in need of a serious recovery programme because while it is still in some semblance of health the time to do it is now. If the Tweed keeps going like it is it will, like the Tay, soon be on its knees; a shadow of its former self while a few profiteers will have cashed in.

I have previously posted a hatchery is not the answer; it is part of a wider solution. No point stocking vast numbers of fry or smolts unless you have the river and inshore conditions that can support them until they go out to sea, and provide enough spawning ground for when they come back. 25 years ago you could fish the Upper Tweed for trout in August and fish with a whickhams fancy or any other gold bodied fly and easily catch 30 salmon parr in an afternoon; now you'd be lucky to catch 2 or 3. So yes there may be marine issues, but the reality is there is a fraction of the number of fish going to the marine in the first place (at least in the Tweed and Tay, and I suspect all other rivers cf The Border Esk chat ongoing in T&S et al). So "the all the problems are at sea" argument (note emphasis) is yet more busted flush talk.

Regardeth

CLaG

[Fruin]

Clag,

I could not agree more with your sentiments. The "all the problems are at sea" argument is presently being used by many to evade their responsibilities in looking after the freshwater environment.
We now have more knowledge of the fish and their environmant, and for that I'm afraid that we all have to thank the scientists, like it or not. However, this wealth of knowledge is sometimes having a negative impact by limiting the work that can be done on certain rivers. I fear that on some rivers we have done plenty of research, but there is probably less work being done to improve stocks than ever before.
There have been mistakes made in the past with erroneous stocking and poor habitat improvement, but the sheer volume of work being done by fisherman and river managers/ghillies/associations, meant that overall the work done had a positive impact.

[charlieh]

ClaG, do you attribute the lack of salmon parr in the upper Tweed to a lack of spawners, or to problems with the river conditions?

It doesn't take many successful redds stock a river to its maximum fry carrying capacity, and as I understand it, the greatest % mortality in a salmon's life cycle occurs in the period from hatching to the first river winter of a fish's life. In a natural environment, salmon produce many, many times more eggs and fry than is needed and the population is regulated principally be environmental factors. In simple terms, if 20 redds will produce sufficient fry to stock a section of river to capacity, 200 redds will add precisely nothing in terms of numbers; indeed I think there is evidence from the Spey that it may result in a slight decrease in fry numbers! The example I mentioned earlier of the recovery of the Wye shows how a severely depleted spawning stock can rebuild the population in quite a small number of generations; all that happens is that the % mortality in the first year of life is much reduced because there isn't the same level of overproduction.

Frankly, I would be surprised if the number of spawners in the Tweed, even if much reduced from where it was 20 years ago, isn't still more than adequate to stock the river to its capacity several times over. If I am correct in this, and if you are correct in your assessment of the decrease in parr numbers, then surely the finger must point to problems with the in-river conditions. Precisely what these are is another question - predation (saw billed ducks), pollution (sheep dips etc), loss of habitat (bank erosion, overshading), reduction in water quality (acidification, siltation) all could be contributory factors.

If the problems lie in the river, a hatchery is of little benefit. The population of fry and parr will always regulate itself down to the level that the river can support. Chucking in any number of fry or parr will not address this except where they are used to seed streams above barriers, where there is no natural salmon population. Rearing to smolt stage (in effect a salmon ranching programme) will improve the catches and the number of returning fish, but does nothing to address the real issues, and in fact simply masks the gravity of the problem. It would be better to spend the money needed to run a hatchery on habitat restoration.

[castlikeaghille]

charlieh said:

ClaG,

1) Do you attribute the lack of salmon parr in the upper Tweed to a lack of spawners, or to problems with the river conditions?


2) Frankly, I would be surprised if the number of spawners in the Tweed, even if much reduced from where it was 20 years ago, isn't still more than adequate to stock the river to its capacity several times over.

3) If I am correct in this, and if you are correct in your assessment of the decrease in parr numbers, then surely the finger must point to problems with the in-river conditions. Precisely what these are is another question - predation (saw billed ducks), pollution (sheep dips etc), loss of habitat (bank erosion, overshading), reduction in water quality (acidification, siltation) all could be contributory factors.

4) If the problems lie in the river, a hatchery is of little benefit. The population of fry and parr will always regulate itself down to the level that the river can support. Chucking in any number of fry or parr will not address this except where they are used to seed streams above barriers, where there is no natural salmon population. Rearing to smolt stage (in effect a salmon ranching programme) will improve the catches and the number of returning fish, but does nothing to address the real issues, and in fact simply masks the gravity of the problem. It would be better to spend the money needed to run a hatchery on habitat restoration.

Another thoughtful post. In response:

1) It is a mixture of both. Although I believe matters are improving on point 2. The major problem to date is most of the improvement work goes on the Ettrick/Yarrow where the spring fish go. The vast spawning areas of Upper Tweed (which produces mostly late summer and autumn fish) receive relatively scant attention.

2) Disagree. By your own observations, a river, all things being equal, will sustain a natural maximum spawning population. I do not believe the current spawning population, even given some changes in the conditions is where the Tweed needs to be by a quantum mile. The Upper and Middle Tweed have showed good hatches of fly life over the last few seasons - I also believe the water quality has improved significantly over the last ten years. I don't believe there are enough eggs being laid is the main reason not increased juvenile mortality.

3) Agreed on the principle. Agreed very highly on the Tay less so in practice on the Tweed

4) Agreed. I think you have to make sure the habitat is in some sort of reasonable order before giving nature a boost. However, I don't think it is a choice between one or other (and certainly not from a cost perspective of a river like the Tweed). Focus your resources on one first, then the other. On smolts, better to have anglers coming to your river and investing money in it while you improve the habitat; although I think they are the option of last resort (typified of systems where they have been used).

Regards

CLaG

[Fruin]

springer said:

Don't kill the spawners we already have, wild and genetically correct (if that bothers you) then we won't need to re-stock.
It might just be that simple.

You may be right for some systems, or for some parts of a system.
Fly-fishing for salmon has to be the most inefficient way of catching fish, especially on medium to large rivers, and as such, I think that the ratio of fish ran to fish caught must be very large. I am all for catch and release but hatcheries, habitat improvements, and a co-ordinated approach to protecting the environment in the estuaries and feeding grounds will do more to assist stocks than simple catch and release.
Having said that, if on some systems like the Tyne, a small band of anglers are just taking the p**s with the number of fish they are killing, something must be done to stop these anglers.

[sagecaster]

charlieh said:

It doesn't take many successful redds stock a river to its maximum fry carrying capacity, and as I understand it, the greatest % mortality in a salmon's life cycle occurs in the period from hatching to the first river winter of a fish's life.

This is the nub, a paradox if you will. You do need a large number of spawners because mortality is so high. A spate or gravel movement at the wrong time could wipe out those few successful redds in a vital part of the river, for eg the Brahn on the Tay, a small, distinct, but vital population are lost for a year. AST have proven this to be the case. So in Utopia you would have ideal spawning conditions the length of the river's catchment each year hence preserving each distinct population. A simplification, but I think you'll get my drift.

Another point regarding smolt mortality. Three or four years ago massive losses of around 50% were recorded off the east coast as the smolts were acclimatising to the saline water. AST investigations suggested that for some reason the smolts ability to adapt to the saline water had been compromised somewhere down the line. They could not establish whether this was a one off or a natural phenomena.

So here's the conundrum, although this 50% is likely to be a very small proportion of the initial hatched alevins, it is still half of the viable stock that was left. So do we try and maximise the half that survives or improve the smolt survival rate. I suspect hatcheries influence the former, just a hunch.

[charlieh]

sagecaster said:

This is the nub, a paradox if you will. You do need a large number of spawners because mortality is so high. A spate or gravel movement at the wrong time could wipe out those few successful redds in a vital part of the river, for eg the Brahn on the Tay, a small, distinct, but vital population are lost for a year. AST have proven this to be the case. So in Utopia you would have ideal spawning conditions the length of the river's catchment each year hence preserving each distinct population. A simplification, but I think you'll get my drift.

Another point regarding smolt mortality. Three or four years ago massive losses of around 50% were recorded off the east coast as the smolts were acclimatising to the saline water. AST investigations suggested that for some reason the smolts ability to adapt to the saline water had been compromised somewhere down the line. They could not establish whether this was a one off or a natural phenomena.

So here's the conundrum, although this 50% is likely to be a very small proportion of the initial hatched alevins, it is still half of the viable stock that was left. So do we try and maximise the half that survives or improve the smolt survival rate. I suspect hatcheries influence the former, just a hunch.

I see where you’re coming from, Sagecaster, but don’t agree with your reasoning. Certainly there will always be redds that fail utterly. However, I maintain that the greatest mortality in a salmon population occurs in the months after hatching, and is largely down to habitat and availability of food.

To illustrate my point, let’s look at a notional example. The figures are arbitrary, but I hope not so wildly unrealistic as to be meaningless.

Say a stretch of river has sufficient habitat and food to support 1000 year-old fry.

Say we have 8 redds in that stretch, each containing on average 5000 fertilised ova.

Say we lose 50% of those redds (to gravel movement, predation and other causes), but that the other 50% suffer no mortality – a bit simplistic I know, but bear with me!

That means we have 20,000 alevins. The river is unable to provide habitat for this number, so they will fairly rapidly be thinned down to the 1000 that we have established this stretch can support.

Now imagine the same stretch of river with half the number of spawners, i.e. 4 redds. Assuming the same rate of failure before hatching we will still have 10,000 alevins. Again this number will be thinned down to the 1,000 carrying capacity.

Now halve the number of redds again to 2, and allow for the same wastage. You still have 5,000 alevins. Just 2 redds (of which one fails) will produce 5 times the number of fish the river can support.

Incidentally, you can continue to play with the figures. Let’s say those 1000 one year olds are reduced to 500 by the time they smolt. With a very pessimistic return rate of only 4% (far worse than a recent North Esk survey that indicated a 7% return rate – down, incidentally from a figure of about 40% in the 1970s), they will provide 20 returning salmon. Assuming the river is very well fished, let’s allow for a 20% catch rate, and assume they are all killed. This brings us (rather neatly ) to a spawning stock of 16 fish, which equates to our 8 redds.

While I accept this is very much simplified, and arbitrary, I think it illustrates the point I’m trying to make. The Wye, given good conditions in the river and at sea, recovered in a matter of a few generations from a state of decimated runs.

[sagecaster]

CH

Succinctly put and I do agree with the theory and for fertile rivers like the Wye/lower Spey this could and probably does work.

However, I mentioned somewhere much early in the thread about the findings of a small west coast river (Applecross) which had been well looked after for generations and thanks to all the problems associated with lice etc fell to one known pair of spawners. This didn't happen over night it took at least 10 years to decline and ultimately a hatchery was introduced to reestablish acceptable stocking levels. As I understand it there were effectively no parr left in the river, why is that?

The practical thinking behind it was that the river reached a critical point where too few salmon were returning to sustain parr stocking densities, hence a gradual decline to zero. For a river as small as that even one pair should have been enough to maintain a semblance of a run. So there must be a point where predation/losses/losses at sea/etc become too overwhelming for the lower densities of spawners.

[charlieh]

The Applecross example is an interesting one - I didn't pick up on it earlier as I hadn't been following the C&R debate closely - having discussed it many, many times both here and on other boards!

I quite agree that there is a critical level below which a stock is not self-sustaining. Quite apart from the fact that, if that one redd is lost, the enitre stock is gone, there is also the issue of the size of the gene pool to consider. While I am a firm believer in the desirability of genetic integrity, I equally wouldn't think that a stock composed entirely of the progeny of just two fish was a good idea. And when stocks fall below a certain level, we can enter an 'extinction spiral', such as happened with the cod stocks on the Grand Banks.

Like others, I'm not completely opposed to hatcheries; they certainly have their place, but I would very much prefer to see them used as a pump priming aid where stocks have fallen to a dangerously low level, rather than a long term solution.

[sagecaster]

charlieh said:

Like others, I'm not completely opposed to hatcheries; they certainly have their place, but I would very much prefer to see them used as a pump priming aid where stocks have fallen to a dangerously low level, rather than a long term solution.

Agreed! ;D The difficulty here is that there is a grey (idealogical) area between 'pump priming' and supplementing the natural stock to a point where stocking is no longer required.

[castlikeaghille]

sagecaster said:

charlieh said:

Like others, I'm not completely opposed to hatcheries; they certainly have their place, but I would very much prefer to see them used as a pump priming aid where stocks have fallen to a dangerously low level, rather than a long term solution.

Agreed! ;D The difficulty here is that there is a grey (idealogical) area between 'pump priming' and supplementing the natural stock to a point where stocking is no longer required.

You might find this observation from Ian Gordon's web site to be of interest:

www.speycaster.co.uk/atlanticsalmon_simplisticview.htm

Regards

CLaG