Freestone Streams - Part Three:
Because the water is usually fast moving pocket water, mayflies found in the
headwaters are usually clingers. Caddisflies are not very plentiful in these
waters because of the acidic level of the water and consequent low algae levels.
Many species of stoneflies are in their prime habitat in the highly oxygenated
water. This water, which is usually slightly acidic, will not support plant life such
as algae. The aquatic insects must rely on other source of food.
When the stream becomes the "run, pool, riffle" type of stream, normally found
in the foothills, the more diverse type of water will usually support other many
other species of mayflies, caddisflies and stoneflies. Mayflies may include
several species of crawlers and swimmers. The caddisfly population and
diversity will increase and include many species of scrapers, predators, and
shedders due to the diverse type of habitat. Stoneflies are still usually present in
the fast water. Since the water has poured through rocks, gravel, sand and
other types of soil and since organic material such as leaves may have
accumulated in the stream, the water is less acidic than it is in the headwaters. It
will normally support specie of aquatic insects that rely on organic material that
has become more prevalent due to the higher pH. Its increased temperature is
also conductive to supporting other insects.
After the stream reaches the valleys it slows down and congregates in larger
pools with riffles. Since the water temperature is much warmer than the water at
higher elevations and since the pH has become even more alkaline, plant growth
may be present. The stream's substrate usually consists of more soil and less
rocks and burrowing mayflies may exist. The caddisfly population may increase
since there is a lot more organic material available for the larvae. Shedders,
predators and scraper species may be prevalent. Stoneflies my not exist in the
less oxygenated warmer water.
An interesting side note to this concerns the Yellow Drake. I have just finished a
program entitled "Mayflies" that has been in production for eight years. It will be
released this month. One of the differences in my DVD and most fly fishing
books on mayflies is that I contend the Yellow Drake and the Golden Drake are
found in water too warm to support trout except maybe in a few streams where
some put and take fish exist. We have traveled the nation for the past eight
years capturing mayflies and studying them and we have not found any Yellow
Drakes where trout fishing is considered good. We always find them in water too
warm for trout. I content the writers like to put pictures of them in their books to
help make them pretty.
One night last week I took my grandson to some of the car places along the strip
in Pigeon Forge. He likes to ride the fast ones. While Angie and I sat on a bench
waiting on my grandson to finish his race, our cocker spaniel dog Biddie began
barking at something on the ground under our feet. It was a beautiful Yellow
Drake mayfly. The Little Pigeon River is right behind the car place. The dun was
attracted by the lights. These mayflies hatch and deposit their eggs in the
evenings. Having traveled to many destinations hundreds of miles away in
search of this mayfly, often without any success, we couldn't help but laugh at
our dog finding one for us in our own back yard. I will try to post a picture of the
drake for you soon.
We own a mayfly spaniel. How about that. Maybe we should take her along on
our next fishing trip.
Coming Up Next:
Freestone Streams - Part 4
Copyright 2008 James Marsh