08/18/09

Insects and other foods the trout may be eating:
1.   Blue-winged Olives - mostly Little BWO - Isolated hatches
2.   Mahogany Duns
3.   Midges - hatching in isolated locations
4.   Little Yellow Stoneflies - hatching (Little Summer Stones)
5.   Slate Drakes - hatching
6.   Cream Cahills - hatching in Isolated locations
7.   Beetles
8.   Grasshoppers
9.   Ants
10. Inch Worms
11. Crane Flies
12. Helligramite
13. Streamers - matching sculpin, baitfish and small crawfish

The Dog Days of Summer - Part  2
I have a PhD is Astronomy (the study of those heavenly bodies) so I am qualified to
explain where the phrase "The Dog Day of Summer" came from, right? Okay, if you
don't buy that then would you believe that I Googled it? According to
Wikipedia
Encyclopedia, the phase came from Sirius, the dog star. It refers the hottest, most
sultry days of summer.

Last Sunday I headed out to make a few cast in Great Smoky Mountains National
Park. There didn't appear to be a rain cloud in the sky until I turned towards the
East on the parkway in Pigeon Forge just before it enters the Spur. The normal
beautiful view of Mount LeConte didn't exist. I couldn't see any of the higher
mountains because they were enclosed in clouds. It looked like it was raining on the
highest mountains but west of the mountains, the sky was clear. That situation is
not uncommon. The Smoky Mountains get a lot of rain during the summer. The
elevations in the park range from 875 to 6,643 feet. This range is about the same
range of elevation as you would experience driving north or south across the
eastern United States from Georgia to Maine. The rainfall amounts range from
approximately 55 inches in the valleys to over 85 inches on some of the higher
peaks in the park. The Pacific Northwest is the only place in the U. S. that has more
rainfall. According to the park, during wet years there is over eight feet of rain that
falls on the higher mountains.

Isolated thunderstorms are common in the park, especially in the high country. One
may drop a half inch or more of rain in one watershed while the watershed across
the next mountain range doesn't get a drop of rain. This is the normal summertime
situation, not the situation that occurred in the recent past for a couple of years
during the drought. Even then, the park still got far more water from rain showers
than the lowland areas surrounding the mountains.

Most of the small headwater streams start from small springs near the top of the
mountains. This used to sound stage to me until I started to explore the situation for
myself. It just seemed strange that a spring would exist on the top of a mountain. I
though they existed only at lower elevations. I was wrong about that. I have found
several small springs at high elevations.

My brother recently built a new home in Laurel Valley at Townsend near the top of
one of the small mountains. Following recent heavy rains, underground water blew
through the bank behind his house taking a pile of rocks with it. The top of the
mountain behind his house is probably not over a hundred feet higher than his
house which has a great view of the park. I wondered just how the water managed
to do what it did. There were no signs of a small stream or any place for the water
to drain from the top of the mountain on the surface. The mountain must of just
swallowed the water and it flowed downhill underground through crevices in the
rocks below the thick topsoil covering the floor of the forest. Where he made a cut
in the face of the mountain in order to flatten out an spot for his house, he exposed
on of the underground routes the water had probably been taking for many years.

In other words, when the rain falls on the top of the mountains in the Smokies, it
doesn't drain off quickly on the surface. Most all of the water is absorbed by the
surface soil beneath the forest. It collects in underground crevices in the rock and
eventually comes back out of the ground at a lower elevation in the form of a spring.

Now I realize that is probably about the most layman description of what happens to
the rainfall on the mountains in the Smokies you could possible read. The point I am
trying to get to, is that the water coming out of the clouds at the higher elevations is
cool and because it is absorbed by the soil and flows beneath the surface of the
ground is comes back out of the ground cool. Most anywhere you dig a hole in the
ground a few feet deep, you are going to find the temperature of the soil is less
than sixty degrees. If I remember right, fifty-five degrees would be normal. The
bottom line is that the water from the rainfall in the high mountains stays cool until it
resurfaces in the form of a very small headwater stream.

These small headwater streams are tightly enclosed in Rhododendron and other
types of trees that keep the sun off of the water. This cover is also is a big factor in
the water temperature. If the forest was cleared and the streams exposed to the
sun, the water would warm up above the point the native brook trout could survive.
In fact, that is what happen to much of the land in the area taken up by the park
some seventy-five years ago. The forest was cleared for timber, the water warmed
up and the brook trout didn't survive. Before that, brook trout existing in most all of
the streams in the park, even at the lower elevations. Clearing the forest of trees
also contributed to the water flowing off the mountains on the surface rather than
underground where it would stay cool.

Since these small headwater streams are formed by water coming out of the ground
in the form of small springs, and since the air temperature in the high mountains is
much cooler than it is at lower elevations, the water stays cool enough for the native
brook trout to survive. The cool water holds enough dissolved oxygen for the trout.
By the way, it also stays cool enough for the wild rainbow trout to survive. Over the
years where the rainbows were able to migrate upstream into the headwaters, they
have been not only been able to survive, they have been able to drastically affect
the population of the native brook trout. Continued..................

Copyright 2009 James Marsh