The Evolution of a Tailwater

  Tailwaters as a whole are a pretty simple science.  In the West they create trout fisheries that normally would not exist.  In the case of the North Platte, three major tailwaters (Miracle Mile, Fremont Canyon and Grey Reef), have stable water conditions suitable to trout and offer year-round fishing opportunities.  The cooler water temperatures and various other abiotic factors(substrate, flow, etc.), help dictate the bug species in the river.

                                           *stomach sample taken May 2011
  Over the past several years all three, particularly Grey Reef, has seen drastic changes in flow.  Last year's record 8,400cfs scoured and re-shaped the river, a flow that has not been seen since the 80s.  Prior to the high flows, years of drought encouraged sediment deposits throughout Grey Reef.  This fine "muck" engulfed entire sections of the river, to some degree altering the bug composition of Grey Reef.
  We are all familiar with the notorious "Reef Worm" aka "Rock Worm" aka little red thing that catches the hell out of em!  Well, it was late winter and we were spending alot of time wadefishing the upper river.  Digging around in some of our favorite spots and occasionally pumping a fish or two, yielded a couple of our little red friends.   This was again brought up by Erik several weeks ago, mentioning the fewer number of blood midges he was seeing.  (Few is a relative term, considering they have existed in huge numbers.)  Without question they are still around, just maybe not by the numbers we once saw.
  Well, what happened?  The "muck" discussed earlier is a composition of fine sediment and silt, a virtual dead zone on the bottom of the river.  The oxygen free environment is friend to very few.  But this is where the  blood midge makes it's living.  It's red color is due to hemoglobin, oxygen rich blood, allowing it to thrive in it's nearly oxygen-free environment.    
  With the high water seen over the past few years tons of sediment have been moved down Grey Reef.  The upper river has been the most altered-a bottom now mostly composed of sand, gravel and cobble.  Substrates friendly to our mayflies, stones and caddis.  Does the mean we are seeing the end of BIG RED?  Absolutely NOT.  But we could be seeing a little shift in invertebrate composition.  Huge hatches of sallies, PMDs and caddis could be on order in 2012....