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Thread: Introducing yellowfish to stillwaters

  1. #21
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    Ja it is a big pity. But I can kind of understand where they are coming from. If you mix strains you will lose genetic variability and its even more irreversible than the introduction of alien species. So a good framework or guidelines needs to be in place and until then its probably just easier to manage if you do not allow anything.

    For instance in the same river system populations can be isolated from each other with waterfalls etc and until these populations have been identified it is a risk to relocate even in the same river.

  2. #22
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    In certain conditions, trout are more invasive than bass. The big difference is that bass breed in dams, trout do not. In a river where both trout and bass co exist, the trout always come out on top. The trout are more predatory, and aggressive. The saving grace for our rivers against the trout, is that trout are generally a lot more finniky regarding PH levels and tannin, where as bass seem to be more tolerant to a wider range of acidity. Where the trout happily take root, they wipe out just about everything. In the Cape trout rivers, bass and trout have been together forever, but the trout dominate. Other rivers where conditions are different, the bass dominate the trout, but all things being even the trout will take out the bass any day. Carp...don't know???
    Quote Originally Posted by yella View Post
    I 100% agree with your sentiments. Trout is to me less of a problem than Carp and Bass because in many conditions they struggle to survive (and do not reproduce as easily). But bass especially should be avoided at all cost. The amount of bass in all our rivers is frightening and the devastation they cause among yellowfish is alarming. Im not too clued up on Carp.

    If I somehow can get the right yellows into our dam it will be a nice experiment.

    P.S. I dont know how common it is but several years ago trout also successfully reproduced on our property, as I caught smaller ones than the sizes we stocked there, and saw them in the streams too. I haven't seen one in a long time though as I think the cormorants loved the smaller ones.
    Disclaimer.... none of my posts are intended to be "expert advice"..just opinions from someone who is willing to help where he can.

  3. #23
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    Andre

    Trout are a cold water fish whereas bass are a warm water fish with a greater temperature range and tolerance. It is not surprising that where trout and bass co-exist the water temperature is such that trout are comfortable (otherwise they would not be present) yet is less than optimal for bass. This may explain why trout win the territory battle in mutually acceptable environments.

    Your post suggests, unintentionally perhaps, that bass are less voracious than trout. This does not match up with my experience.
    "The best way to shrink a fish is with with a ruler - the best way to grow a fish is with a beer."

  4. #24
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    Quote Originally Posted by Andre View Post
    In certain conditions, trout are more invasive than bass. The big difference is that bass breed in dams, trout do not. In a river where both trout and bass co exist, the trout always come out on top. The trout are more predatory, and aggressive. The saving grace for our rivers against the trout, is that trout are generally a lot more finniky regarding PH levels and tannin, where as bass seem to be more tolerant to a wider range of acidity. Where the trout happily take root, they wipe out just about everything. In the Cape trout rivers, bass and trout have been together forever, but the trout dominate. Other rivers where conditions are different, the bass dominate the trout, but all things being even the trout will take out the bass any day. Carp...don't know???
    Andre, do you have any facts to back up your point of view? Trout and redfins have been living together in many of our rivers for over a hundred years. You can catch them in the same pools with successive casts. The Krom trib off the Smalblaar is a good example of this but there are many others. Like Justin said, trout and bass have different temp ranges that suit them. Fish the Smalblaar in mid summer and you would think the river had no trout as all you will catch is bass. In colder conditions the trout dominate and you are unlikely to hook a single bass. I can guarantee you that if trout were in the Rondegat as opposed to Smallmouth Bass, you would not have total devastation of other species (besides larger clans) so I am not sure where you get this idea that trout are more aggressive and more predatory?
    “Apparently people don't like the truth, but I do like it; I like it because it upsets a lot of people. If you show them enough times that their arguments are bullshit, then maybe just once, one of them will say, 'Oh! Wait a minute - I was wrong.' I live for that happening. Rare, I assure you” ― Lemmy Kilmister

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  5. #25
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    No I don't have any facts, just what I notice regarding our CPS rivers. The bass and trout have both been there for a long time, yet the trout seem to be in control of the bass population. Perhaps the conditions are more suitable to trout than to bass. Lower down, in the Breede, it seems the bass are more dominant.
    The well known fish scientist from Cape Nature seems to be quite certain (according to some of his reports) that the trout are a bigger threat to the indigenous fish than the bass. Perhaps its because the trout are better suited to conditions where redfin etc. exist, than the bass are.
    Disclaimer.... none of my posts are intended to be "expert advice"..just opinions from someone who is willing to help where he can.

  6. #26
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    Quote Originally Posted by Andre View Post
    The well known fish scientist from Cape Nature seems to be quite certain (according to some of his reports) that the trout are a bigger threat to the indigenous fish than the bass. Perhaps its because the trout are better suited to conditions where redfin etc. exist, than the bass are.
    Could also be that he knows how to create ongoing employment and funding oppurtunities with the local ordinances??
    Mario Geldenhuys
    Smallstream fanatic, plus I do some other things that I can't tell you about

    "All the tips or magical insights in the world can't replace devotion, dedication, commitment, and gumption - and there is not secret in that" - Glenn Brackett

  7. #27
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    In America, they are doing a lot of research on the various strains of trout. Some info about the Cut throat.
    http://www.denverpost.com/ci_2161972...olorado-stream

    The trout that we have in SA, is probably such a pea soup of different strains, that genetically, they are worth nothing.
    From a fishing value, yes, that is totally different.

    Lots of other info about the research on the different genetic strains of the rainbow trout etc on the net.
    Korrie Broos

    Don't go knocking on Death's door, ring the bell and run like hell. He hates it. (anon)
    Nymphing, adds depth to your fly fishing.
    Nymphing, is fly fishing in another dimension

  8. #28
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    From Slovenia to Northern Europe, to America right thru Africa, Australia and New Zealand, every where they are concerned about protecting the last available pure strains of fish.
    http://www2.arnes.si/~asnoj2/prenos/...marmoratus.pdf

    Google genetics Salmon. Or dangers of fish farming on genetics etc etc.
    Korrie Broos

    Don't go knocking on Death's door, ring the bell and run like hell. He hates it. (anon)
    Nymphing, adds depth to your fly fishing.
    Nymphing, is fly fishing in another dimension

  9. #29
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    Quote Originally Posted by Korrie View Post
    In America, they are doing a lot of research on the various strains of trout. Some info about the Cut throat.
    http://www.denverpost.com/ci_2161972...olorado-stream

    The trout that we have in SA, is probably such a pea soup of different strains, that genetically, they are worth nothing.
    From a fishing value, yes, that is totally different.

    Lots of other info about the research on the different genetic strains of the rainbow trout etc on the net.
    I would have thought that Western Cape Trout have adapted to warmer water conditions and therefore genetically they would have some value. (my 2 ronts)
    So Long, and Thanks for All the Fish.

  10. #30
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    Quote Originally Posted by Korrie View Post
    From Slovenia to Northern Europe, to America right thru Africa, Australia and New Zealand, every where they are concerned about protecting the last available pure strains of fish.
    http://www2.arnes.si/~asnoj2/prenos/...marmoratus.pdf

    Google genetics Salmon. Or dangers of fish farming on genetics etc etc.
    This sounds like something out of a 1944 German propaganda poster

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