11/26/08

Fishing Cold Water in the Great Smoky Mountains - Part Two

Trout do not position themselves or hold in cold water in the same places that they
occupy in warm water. Several factors account for this. One is that oxygen is not a
problem. Cold water holds more dissolved oxygen than warm water. From an
oxygen standpoint, the trout could position themselves anywhere in the stream if
the water is cold. In warm water they must position themselves in water that is
aerated enough to provide the oxygen they need. This is usually the faster moving
water of runs and riffles.

Trout in warm water have a high rate of metabolism. They must eat a lot of food to
survive. They will position themselves where ever they can acquire the most food.
This is usually the current seams and almost always is in faster or moderately
moving water. In cold water, the trout have a lower rate of metabolism. They need
less food to survive and they don't have to position themselves in the faster moving
water to acquire enough food to survive. If they did, they would expend more
energy and need even more food. In cold water they position themselves in the
slower moving water.

That seems to make it simple until you try to determine where slow moving water
exist in a stream. In the freestone streams of Great Smoky Mountains National Park,
slow water exist not only in the places you can observe from above the surface but
also in the area of fast moving water below the surface. Every rock or boulder in the
stream changes the flow of current and the speed of the water. There is water
moving very slow, some almost still and some that moves only moderately even in
the fast runs of the streams. In fact these obstructions can cause the water to flow
in the opposite direction. If we see this situation on the surface, we refer to it as an
eddy.

Determining where the slower moving water exist in the streams is not exactly easy
to do. The trout don't necessarily hold in shallow water around the edges of the
stream, behind large boulders and other places where the only slow water in a
stream appears to be. They can find slow moving and even still water within areas
of the stream that from the surface appears to be only fast moving water. In many
cases they can position themselves near or on the bottom and be in water that is
barely moving downstream. The deepest spots in a stream usually have slower
moving water due to obstructions upstream that are located at a higher level or
elevation. That is why they are the deepest spots. That is why you will often see
trout in clear, cold water appear to be lying on the bottom of pools and areas of
water where you can clearly see the bottom. They can also be near or on the
bottom in areas of the stream that is moving very fast on or near the surface. In
those cases, you cannot spot them. In fact there are usually more trout holding in
those areas than they are in the deeper areas of slower moving water such as
pools.

Unlike many anglers think, trout don't position themselves in cold water on or near
the bottom because the water is warmer. First of all, it isn't any warmer and
secondly, they could care less anyway. They are perfectly comfortable in cold water
that is forty degrees F. They position themselves there to be in slow moving water
that is safe from overhead predators. They can find slow moving and even still
water on and near the surface in most streams and they will occasionally be found
in such places; but, anytime they are positioned in shallow water they are subject to
being eaten by predatory birds and mammals. They will normally only move to
shallow, slow moving cold water when there is an ample amount of food there. For
example, when the blue quills begin to hatch and the water temperature is only in
the high forties, they will move in and out of the shallow, slow moving water to feed
on the blue quill nymphs and emerging duns because that is where they hatch.  

Now you may think from what I have said so far that there is a very simple solution.
Just fish the deepest water in the stream. That is not a bad idea but doing so isn't
exactly easy. Fishing a fly that moves at the same speed other drifting food is
moving near the bottom in deeper water is not an easy thing to do. In fact it is quite
difficult to do in most cases. For example, trout holding in deep, slow moving water
of runs have the advantage of being concealed by the broken surface of the fast
water above. They are hidden from you and that puts you into a blind fishing
situation. You don't know exactly where the slow moving water is. Even worse, you
will find it very difficult to get the fly to drift at the speed of the slow moving current
in the deeper holes and pockets of the run. That is because the current near the
surface above the slow moving current on the bottom is moving very fast. Even
when you weight the fly and get it down, the fast water on the surface pulling on
your leader and line sweeps you fly through the slow water on the bottom much
faster than natural food drifts in the slow current. The fast moving fly may even tend
to spook the trout holding in such places. Imagine what happens when the trout are
holding in slow moving water near the bottom and suddenly a fly shoots through
their home at the speed of light.

You can resort to fishing the slow water on the bottoms of the pools. The problem
with fishing for the trout holding in the slow moving water where you can see them is
that they can also see you. Trout holding near the surface have a very small
window of vision. Trout holding in deep, clear water have a very large window of
vision and can detect objects above the surface much easier and much farther from
them. Another inherent problem is that when your fly is moving slowly through their
home they can get a very good look at it. They fly needs to look more realistic than
one moving at a fast rate of speed.

Both types of water creates yet another problem for anglers. You simply cannot
present your fly to a lot of trout in any given amount of time. It is slow fishing.
Making short, upstream cast to surface feeding trout gives you a lot of shots in a
short time at the fish feeding there. That isn't the case when you are presenting
your fly to trout positioned in deep water - especially when they are not going to
move but maybe a few inches to eat anything.

So far all I have done is tell you about some of the problems you face in fishing cold
water. I haven't told you anything you can do about the problems. I think you can
see why catching trout in very cold water isn't easy. To Be Continued......

Copyright 2008 James Marsh