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Thread: Spring Fish

  1. #1

    Default Spring Fish

    Sorry if the question has been asked before but has it ever been definitively proven that spring fish breed spring fish?

  2. #2
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    undoubtedly.

    There would have been no reason for compulsory C & R for spring fish with out this evidence.

    Think how bad the spring fish numbers would be now, if this scientifically proven safety mechanism wasn't in place.

    Regards

    Mows

  3. #3

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    Quote Originally Posted by MeanwhileBackAtTheRanch View Post
    Sorry if the question has been asked before but has it ever been definitively proven that spring fish breed spring fish?
    Quite the opposite. There isn't any evidence at all that they do, in fact all available evidence shows they do not.

  4. #4

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    That seems to have cleared the question up Spring Fish

    Sent from my SM-J320FN using Tapatalk

  5. #5

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    My understanding was that the majority of spring salmon were hen fish and that this and their larger egg carrying capacity was the reason for paying particular attention to their preservation. I watched an interview with Ken Whelan where he spoke of an experiment on the Burrishule where grilse were ranched from a particular part of the catchment and to everyone’s surprise they returned as spring fish.

  6. #6

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    Quote Originally Posted by mows View Post
    undoubtedly.

    There would have been no reason for compulsory C & R for spring fish with out this evidence.

    Think how bad the spring fish numbers would be now, if this scientifically proven safety mechanism wasn't in place.

    Regards

    Mows
    You forgot your smiley!

  7. #7
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    Some spring fish breed spring fish, some not.
    There were some interesting surveys on the Spey and North Esk in that question nearly 20years ago.

  8. #8

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    Quote Originally Posted by Loxie View Post
    Quite the opposite. There isn't any evidence at all that they do, in fact all available evidence shows they do not.
    If there isn't any evidence, how about applying a little bit of common sense then? River Tweed could present a good case study. Spring runs spawn there in Ettrick trib while summer and autumn fish tend to run straight to upper river or haggle in middle reaches and potentially spawn there. Do you think that wiping out Ettrick (spring) run would result in summer/autumn fish taking Ettrick spawning grounds? If not, then most likely spring Ettrick fish will breed next generation of spring Ettrick run. How wrong is this theory?

  9. #9
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    Interesting statement from the Tweed here

    https://www.rtc.org.uk/Conservation_...ing_Salmon.pdf

    note item 5 in the summary

    During the last Spring Salmon dominated phase (c.1920 - c.1960) a much greater
    area of the catchment must have produced Spring Salmon than now does so. This
    means that those areas / populations that still do so are of particular value as they
    represent the "hard" Spring Salmon stocks that can retain the early running
    characteristic when others have lost this.
    characteristic?

  10. #10
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    Quote Originally Posted by pol_angler View Post
    If there isn't any evidence, how about applying a little bit of common sense then? River Tweed could present a good case study. Spring runs spawn there in Ettrick trib while summer and autumn fish tend to run straight to upper river or haggle in middle reaches and potentially spawn there. Do you think that wiping out Ettrick (spring) run would result in summer/autumn fish taking Ettrick spawning grounds? If not, then most likely spring Ettrick fish will breed next generation of spring Ettrick run. How wrong is this theory?
    Unfortunately it's wrong and doesn't withstand scientific scrutiny.

    Starting with the Tweed, what is the evidence supporting the notion of all springers going to the Ettrick? Or is it a repetition of a strongly held local belief? My reason for saying that is that I don't recall ever seeing any research data from the esteemed Tweed scientists reinforcing the notion. In any event few fish enter the Ettrick until later in the season (evident from the catch returns), so presumably they will have mixed with others somewhere lower down the system. Once that happens, how do you tell them apart?

    Moreover, how do you account for the well demonstrated cyclical changes in run timings and class composition on the Tweed, which were explained in detail in a major study a few years ago? These things are in continuous evolution and change.

    Looking beyond the Tweed:

    - In the Dee Girnock Burn study, which involved physically counting both smolts and adults over an extended period, the returning and seasonal correlation was as low as 36%. This means that it was less certain than tossing a coin. In other words, it could just as easily be wholly random. This study and others elsewhere underline the point that salmon do not unfailingly return to their natal stream, they stray as a survival strategy (how they survived the Ice Ages) and this may involve up to 20% or more of the population, depending on local environmental factors (e.g. drought).
    - A good example of localised straying comes from the Burn Beck project on the Ure. The removal of the weir opened Burn Beck to spawning salmon for the first time in 100 years. No living salmon had ever spawned there. Yet during the first winter after the opening some 20-30 redds were identified in this stream. The salmon went there because they found it attractive. The population in the Ure is well below capacity and there are huge potential spawning areas available, so they weren't forced into the Burn by overcrowding elsewhere.
    - The progress of salmon up a river is influenced by so many variables - water level and temperature, flow composition, oxygen availability etc - that assertions are likely to be seriously unfounded. Tagging studies on several rivers underlined this point. In one case, two tagged fish from the same year cohort entered the river together. One ran about 5 miles, dropped anchor and stayed there until September when it covered the next 75 miles in under a week; the other progressed steadily before stopping further upstream. Another fish in the sample ran 30+ miles, then turned round and went back to the lower reaches. Faced with that sort of data I am uncomfortable with strong assertions on running behaviour.
    - If spring fish were hard-wired to run in spring for successive generations, then genetic adaptation would occur. You can change mouse DNA through behaviour shift in 3 generations (the strawberry aversion experiment). The Norwegian research noted minor differences in spring running fish, but nothing so distinct as to suggest either enduring DNA change, still less species separation. Springers are not a separate breed.

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