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  1. #31
    Join Date
    Feb 2010
    Location
    France, near Sancerre
    Posts
    226

    Default Re: Does Stocking Help Salmon Returns? Results Using 50-years of Monitoring Data

    Quote Originally Posted by bobmiddlepoint View Post
    The point is our rivers can (or could) produce salmon without having to stock and if the only way you could get a viable salmon catch from them now was by smolt stocking it would be a staggering admission of our failure
    We've got exactly that problem here: after years and years of hesitating restoration policy, facts are that people are superstitiously thinking that things are done for salmon and that they are back thanks to stocking and so why doing something else when millions are already spent? No! The stocked fish represents only half of the population in the best case (with total population of less than one thousand, i.e 2% of the original one!). And of course there are still impassable weirs scattered everywhere, hydro-plant poorly equipped (if only they are!) that are crushing up to one third of the smolts, etc, etc... But that is "so easy" to put young not viable fish in the river.
    Notwithstanding the big degenerating threat that this artificially bred fish represents to the wild ones.
    What is civilization? A distinct thing or an advanced stage in barbarity? (H.Melville)

  2. #32
    Join Date
    Feb 2013
    Location
    Co. Armagh.
    Posts
    1,451

    Default Re: Does Stocking Help Salmon Returns? Results Using 50-years of Monitoring Data

    I don't have a dog in this race but, everyone's speaking in absolutes here and I don't think we can do that safely. As an example, what about the Lagan in Northern Ireland? Salmon were declared extinct here and were re-introduced by Professor Robert Rozell's team from Queen's University Belfast. Various stocks were sampled and fed fry introduced. The first returns were confirmed in 1990 and for several years the returning fish were captured on feeder streams and used as brood stock. The theory was along the lines that survivors of this 'shotgun' stocking must contain enough of the required genetics or they wouldn't have made it back. All stocking has now ceased as the run is considered self sustaining if fragile. Monitoring continues of course. Several years on and the Lagan has a small run of salmon again after an absence of two centuries. Perhaps they aren't native as such, but they are certainly wild and have been for several generations now. Furthermore, the new, cross bred fish have now been established as distinct from their progenitors. Whether the run survives the various threats it faces, predation, pollution, poaching etc. etc. is in the lap of the gods but the fact is wild salmon are back in the Lagan because of the stocking. Perhaps it's the naive environment but it has worked.
    Perhaps we should say that in general stocking seems not to help but more research is needed.

    S.
    "There are a thousand ways to make a fishing rod....most of them are right:- R.L. Nunley.

  3. #33
    Join Date
    May 2006
    Location
    White City, Oregon, USA.
    Posts
    22,372

    Default Re: Does Stocking Help Salmon Returns? Results Using 50-years of Monitoring Data

    Quote Originally Posted by petevicar View Post
    Surely catch returns are a measure.
    Here in Washington/Oregon State's you purchase a general fishing lic., if you want to fish for Salmon/Steelhead that's a second/separate ticket. Ditto for salt water fishing.

    With your second card you get what's called a 'punch card' where you record your 'landings,' C & R included. As all the river's (in some cases sections of larger river's) are given 'number's' to record the date/location the game people can get a very good idea of how a river produced in a given year.

    Above and beyond punch card a given number of fish get a 'tag' connected to one of the fins with a 'control number.' Each is individual but the 'number' gives their 'life history.'
    Fred Evans - White City, Oregon

  4. #34

    Default Re: Does Stocking Help Salmon Returns? Results Using 50-years of Monitoring Data

    Im a bit confused about this wild fish you go on about. Most rivers in Scotland at some time over the last 50 years have had hatcheries on them. All the netting stations also ran hatcheries.
    On the Norway issue, I fished rivers, that were Brough back threw hatchery fish. And they produce some big fish.
    If these hatcheries have been around for years surely the wild fish will have crossed at some time ?
    Was the river Wye not stocked with Ryne fish years ago ?

  5. #35
    Join Date
    Feb 2010
    Location
    France, near Sancerre
    Posts
    226

    Default Re: Does Stocking Help Salmon Returns? Results Using 50-years of Monitoring Data

    Yes they've been stocked. But then you've got to distinguish several situations:

    1- population extinct: stocking has no effect, the introduced fish can not establish; as far as I know, from all the scientific papers I gathered (and there are even publication about the efficiency of stocking) there is absolutely not a single example where there has been any kind of success...

    2- population depleted, stocked with non native fish: usually, the non native are getting much diluted in the natural strain as soon as natural conditions improve and original population recover (there are many, many examples but here is one: some French rivers were stocked with Scottish and Canadian salmon for decades and genetics are showing that the ingress of external characteristics is almost not detectable; one river from Normandy was stocked with French Southwestern fish just to give a boost... and those fish are now in minority; that was completely useless).

    3- population depleted, stocked with native or very neighboring fish: effect on the population is null, you can only expect better adult return but in no case an improvement in salmon population (that's not the same: when stocking is stopped, population is collapsing); it is moreover harmful to wild strain as they are very close and can mix, and therefore transmit inherited domestic traits. That is the case here in the Allier but also in Norway on the Vosso.

    That's just to make it short as there are hundreds of pages of dedicated literacy on the subject. Yes , it looks easy to think that we just have to put fish in the river to get some, but it is not working. We've got to accept that and work on some other solutions, may be less easy at first but only long term lasting... Anyway, as somebody else said above, a "put and take fishery" is not my idea about a wild river. One may tell you to let him make everything for industry and agriculture, let's say transform the river in a pipe, provided he buys you some fish to put in it and have some fun. Would you accept? Till what point? Is that the life we expect to live?
    What is civilization? A distinct thing or an advanced stage in barbarity? (H.Melville)

  6. #36

    Default Re: Does Stocking Help Salmon Returns? Results Using 50-years of Monitoring Data

    As has been noted, there is stocking and then there is stocking.

    For example, everyone is mentioning the Rangas. What about the Tungfluot? Another Icelandic river, but unlike the Rangas did have a very small population of self sustaining salmon, which were used to create a ranching system. Along with fish passes which opened up more spawning ground the catches have gone from c 200 p/a to 2500 p/a.

    I don't think ranching is exclusively the answer, but it seems silly to dismiss it as never part of the answer. We must improve habitat and access to spawning, buy out nets, eliminate open cage farming, promote catch and release, tackle avian and other sources of predation and I am sure in some cases, consider proper stocking / ranching.

    I would like to see a small self contained system, such as some of the Hebridean rivers, which have far below historic levels of returning salmon, tested with some Icelandic style ranching...

  7. #37
    Join Date
    Sep 2017
    Location
    Thick end of the stick.
    Posts
    622

    Default Re: Does Stocking Help Salmon Returns? Results Using 50-years of Monitoring Data

    Quote Originally Posted by sammyc View Post
    I would like to see a small self contained system, such as some of the Hebridean rivers, which have far below historic levels of returning salmon, tested with some Icelandic style ranching...
    Of course it would work the same way that it worked at Delphi but it would be an artificial fishery. Yes there would be salmon to keep the anglers happy but there still wouldn't be a self sustaining population of fish. As soon as you stop ranching the runs would fail again, it just isn't a long term solution.
    Also don't think that the Hebrides are all full of systems that are in perfect condition in the freshwater environment but lacking in salmon. Some are in a shocking state with neglected spawning grounds and unregulated fish farm dams.
    Maxima (or Drennan Sub Surface Green) forever

  8. #38

    Default Re: Does Stocking Help Salmon Returns? Results Using 50-years of Monitoring Data

    Quote Originally Posted by raphael View Post
    Yes they've been stocked. But then you've got to distinguish several situations:

    1- population extinct: stocking has no effect, the introduced fish can not establish; as far as I know, from all the scientific papers I gathered (and there are even publication about the efficiency of stocking) there is absolutely not a single example where there has been any kind of success...



    2- population depleted, stocked with non native fish: usually, the non native are getting much diluted in the natural strain as soon as natural conditions improve and original population recover (there are many, many examples but here is one: some French rivers were stocked with Scottish and Canadian salmon for decades and genetics are showing that the ingress of external characteristics is almost not detectable; one river from Normandy was stocked with French Southwestern fish just to give a boost... and those fish are now in minority; that was completely useless).

    3- population depleted, stocked with native or very neighboring fish: effect on the population is null, you can only expect better adult return but in no case an improvement in salmon population (that's not the same: when stocking is stopped, population is collapsing); it is moreover harmful to wild strain as they are very close and can mix, and therefore transmit inherited domestic traits. That is the case here in the Allier but also in Norway on the Vosso.

    That's just to make it short as there are hundreds of pages of dedicated literacy on the subject. Yes , it looks easy to think that we just have to put fish in the river to get some, but it is not working. We've got to accept that and work on some other solutions, may be less easy at first but only long term lasting... Anyway, as somebody else said above, a "put and take fishery" is not my idea about a wild river. One may tell you to let him make everything for industry and agriculture, let's say transform the river in a pipe, provided he buys you some fish to put in it and have some fun. Would you accept? Till what point? Is that the life we expect to live?
    What about the Norweagan rivers, that had all natural fish killed, then re stocked. Laerdal, Beiarelva, Saltaselva. Many the rivers in Norway were effected by a deadly parasite, therefore all fish were killed, and the river treated. After end of the treatment , stocked fish were re introduced , and the rivers are back producing good runs of big fish.
    Could we not run a system on the same formula as they used in Norway.

  9. #39
    Join Date
    Feb 2010
    Location
    France, near Sancerre
    Posts
    226

    Default Re: Does Stocking Help Salmon Returns? Results Using 50-years of Monitoring Data

    No, the fish that were at sea were not killed when the river was treated with rotenone (problem was dactylogyrus, a parasite that lives only in freshwater). These fish are the ones who performed the work for rebuilding the stock; and with river in good ecological condition, it goes fast.

    About the river Lagan quoted above, it would be interesting to have genetic sample of the population and to check if the fish are really the siblings of the introduced ones or if they are coming from neighboring catchments (that's a strong probability with regards to today's knowledge). And anyway, as said population is fragile, i.e performing low, it's not a solution...
    Last edited by raphael; 19-06-2018 at 08:39 PM.
    What is civilization? A distinct thing or an advanced stage in barbarity? (H.Melville)

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