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Thread: A.s.t.

  1. #21
    Join Date
    Nov 2007
    Location
    Isle of Lewis
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    1,656

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    Quote Originally Posted by Kylesider View Post
    Before they get to the trap at Achanalt they will have experienced a whole host of environmental conditions. In low flow years, particularly if water temperature is also low, migration delays may be a big problem. In turn the degree of smoltification of many fish may be very different between years for a given date. This in turn may affect their behaviour e.g. migrating in daylight or at night. Additionally, whilst their is a minimum compensation flow on the main stem, higher flows from spill events, accretion downstream of Achilty etc may aid survival. Use of dummy tags in the way you suggest has been mentioned in the meetings between us local biologists and representatives of AST. It could be an important stepping stone in assessing direct tagging mortality. However, indirect mortality will be more difficult to tease out. Surviving in a tank or cage is one thing, surviving when you have a 5lb brownie chasing you is another...
    Yes, there is, sadly, a high concentration of 5lb brownies just below the dam.
    Maybe not the best advert for fisheries management best practice.

  2. #22

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    Quote Originally Posted by Roag Fisher View Post
    Yes, there is, sadly, a high concentration of 5lb brownies just below the dam.
    Maybe not the best advert for fisheries management best practice.
    There is a pretty easy solution...

  3. #23
    Join Date
    Nov 2009
    Location
    In a cooling North Atlantic...
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    1,134

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    Quote Originally Posted by goosander View Post
    I only have my eyes and what my fly catches to tell about my river. Some years we get smolts that are about 9 inches long. This is after the previous year being wet. Other years the smolts are about 6 inches and this usually means that we are in for a dryish season. My eyes tell me that broods of 3-6 goosanders mean a shortage of food [parr].Not very scientific but a lot cheaper than other forms of counting.
    Bob.
    It's easy sums, g: per adult 200g/day times cohort (4 x 100gms) per day so about per unit family, about 250-300 kilograms per year. So, if salmon fecundity at 6000 eggs x mortality x smoltification rate, it is a significant mortality enhanced ratio. Apparently.

    You know what, such has been the collective farce incorporating board and trust they cannot even publish parr or smolt figures - any basis for any plan. Top gravy for the custodiata

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