Lyndon,
Thanks, I remember that thread well. It may be wrong, but I go by the tide times for Kolan river mouth (myra)..and the only probable adjustment (or experience) different to my thoughts last year, is I dont think it has a physical effect on water movement (ie currents etc)...but it has a mild effect on the external weather...mostly a breeze change that I have noticed...and mabey other 'forces' that I cant detect that cause a small window.
here is another theory, anyone can smash it to bits if you like....I certainly wont be offended.
Having Spuds father in law in charge of letting water out of the dam has been a great help working out this theory...Now, remember the trollathon days in the basin area around Oct over past years particularly 2006 and 07...except this 2008 2009 where it has occoured (albiet less) later say mid to late Nov....well I have coincided this with the significant releases in water (not letting out little bits here and there)...but big dumps for continued periods.
Would or could this be creating an under current drawing towards the wall that we cant detect...but the fish can..making them think 'its time to go to sea'......Further to this this alledged migration has occoured more pronounced as with lower levels of the lake.
My analogy to base this theory is a bath tub. You have a full bath tub and pull the plug. the water moving out appears less on the surface....and is probably not creating a massive undercurrent either as there is plenty of water pressure to suck/push it down the hole....now as it drops further...momentum takes hold....water is in its narrowest form (ie Mondy right now..nearly back to river beds)....thus a stronger under current...even a surface current would occour. these currents may well be felt by the inceased sensory abilities of barra....thus the instinctive migration each year.
Its out there I know, but its worth some thought and discussion. I had been talking to Foxie about it also.
Sorry to hijack Trev...its sort of the same ballpark topic possible worth a metion.
Cheers Steve