12/29/11
Insects and other foods the trout may be eating:
1.    Blue-winged Olives
2.    Midges
3.    Sculpin, Minnows (Streamers)

Fishing Cold Water - Part 16
It isn't easy describing various sections of streams that vary greatly in size. Just for one
example, if I use the word "pool", a large stream in the lower elevations can have a very large
pool that's several feet deep, whereas a large pool in a middle elevation stream may only be
three feet deep. I really should use a program that allowed me to illustrate cross sections of
the streams to help explain what I want to point out. I just don't have the time to do that. In the
last article on cold water I pointed out two things to consider - the depth and speed of the
water..

Depth:
When the water is very cold, lets say less than 45 degrees, trout don't necessarily get in the
deepest water that's available. That doesn't offer the fish any advantage. The water
temperature isn't any warmer at the bottom and they don't need the extra depth for protection
from their predators. I'm pointing this out to make sure you don't think I'm implying that trout
will seek the deepest water in the stream. The depth they choose is more a product of the
amount of light penetration. This is controlled by sky conditions and water clarity. For
example, If the water is stained and again, still or moving slowly, trout may hold in very shallow
water. If the water is very clear, still or moving slowly, and it's up in the day and the skies are
clear, the trout will tend to hold in deeper water.

The only thing that will change this situation is a concentration of food and again, that's the
exception, not the rule. A developing hatch is the only thing that's going to create a larger
concentrate of insects. When the water temperature is less than 45 degrees, there's very few
insects in the streams of the Smokies other than Midges and Little Winter Stoneflies that will
hatch. Some species of Blue-winged Olives hatch in the high forties, not the low forties.

Speed:
Finding still or slow moving water in a pocket water stream isn't as easy as it appears to be.
As mentioned in the last article, that's because slow moving water can be found beneath fast
moving water on and near the surface. When the surface of the water is rough, meaning not
smooth and slick, your view of  what's below the surface is distorted. The trout's view of what's
above the water through their relatively small window of vision is also distorted by the rippled
surface. That helps to keep them hidden from predators. Trout will hold below fast water with
a rough or rippled surface. They will also hold under plunges with lots of bubbles on the
surface. Just because the surface of the water is rough and moving fast doesn't mean that all
the water below the surface is moving fast. There can be very slow moving water below fast
surface water. It can even be moving in the opposite direction of the surface water - an
underwater eddy. It's even possible that there's slow moving water two or three feet below a
plunge at the head of a pool.  

If the surface of the water isn't broken, meaning it's flowing slow and smoothly, using polarized
glasses you can see the bottom of deep water on a clear day, provided the water is clear. If
you carefully examine the water from a low vantage point below the trout's line of vision, you
can see trout that may be holding in the deeper water. They are not easy to see, but once
you get used to what to look for, you can spot them if they are there. It's areas of water that's
below the fast water with a broken or rippled surface that's hidden from your view.

If the bottom of a stream is relatively flat, the speed of the water on the bottom is usually close
to the speed of the water near the surface. If you fished the deep water on the bottom of such
an area when the water is very cold, you would be fishing an area that wasn't holding any
trout. If someone simply "presented their fly on the bottom of the deeper water of a stream,
they may be fishing water that doesn't hold trout much of the time they are fishing. It depends
on the stream's bottom configuration, but you may well have to fish a long time before you get
lucky enough to be presenting your fly in an area of water that's moving slow enough to hold
cold water trout. To offer someone such advise as to "get your fly on the bottom of the
stream" is really worth very little. It doesn't eliminate much water.

Any upstream obstruction on the bottom of any particular area of a stream causes a change
in the speed of the water on or near the bottom. For example, the water down in smaller size
holes in the bottom surrounded by water that's shallower than the hole is usually still or
moving slowly. More often, slow water on the bottom of a stream is caused by the same thing
that causes it to move slowly on the surface of a stream - upstream obstructions. Picture a
typical large boulder that protrudes above the surface of a fast water stream. The water has
to flow around it, usually around both side of it. The water behind it ranges from almost still to
moving slowly, and sometimes, even in the opposite direction. In other words, it is obvious
there's a small "pool" behind every large boulder in the stream that protrudes out of the water.
What isn't so obvious is the fact there's also a slower moving area of water downstream of
every large boulder that's below the surface of the water.

In the above scenario, I used a large boulder to help illustrate a place that the speed of the
water changes; however, it doesn't take a large boulder to do that. Every rock that protrudes
above the bottom of a stream creates the same situation. It doesn't take a very large rock to
create a "volume" of slow moving water that's large enough for a trout to hold in when the
water is very cold. Again, if there's enough light and the water is clear, you can spot these
underwater obstructions but only if they are under water that's relatively smooth. You can't
see these types of obstructions under fast water with a broken or rippled surface.

In some cases, large boulders that protrude out of water create a deep enough pocket of slow
moving water to hold trout in cold water. Holes behind large boulders are worth fishing if they
are deep enough to give the trout protection from overhead predators.

Species of Trout:
So far, everything I have written disregards the three different species of trout that inhibit the
streams of the Smokies. The areas of water that rainbow trout will hold in are different from
the areas of water larger brown trout will hold in. The smaller browns don't vary greatly from
the rainbows, but once they reach about a foot long, they change their eating habits. You will
also find that brook trout will hold in different areas of a stream than either of the other two
species. Generally, the larger brown trout will get up under obstructions to not only get out of
the current, but also to hide and seek their prey. Rainbows and small brown trout aren't prone
to "hide" in the same manner as the larger brown trout.

I will get into this later, but I did want to point that out in the event you thought I was ignoring it
or in the event you aren't familiar with their differences.
Copyright 2011 James Marsh