In the late 70's, I fished the
professional B.A.S.S.circuit. I
remember meeting Dr. Hill, an
avid bass angler who invented
the electronic pH meter that you
mounted on your bass boat. It
gave an instant readout on the
pH of the water. Anglers
thought they had a new
instrument that was a big key in
I believe Darrel Lowrance
(Lowrance Electronics) was the
one who first introduced it for
Dr. Hill. I did not know a
competing angler that was not
given one or who didn't
purchase one. We knew the
best pH for bass was slightly
alkaline, so in the three day
practice period, we would run
all over the lake the tournament
was held on looking for water
with a high pH. The plan was to
eliminate the water with the
lower than preferred pH.
In almost all of the lakes we
fished from coast to coast, the
problem with the new pH meter
soon became obvious. We
couldn't find any bad water. It all
had an acceptable pH level. I
guess that 's why Dr. Hill's ,or
Darrel Lowrance's pH meter is
not around today.
I don't think it will help you to
catch trout by going all over the
park measuring the pH of the
water. It will help you to
understand the role pH plays
in the streams trout and aquatic
insects habitat. It will also help
you to understand one of the
problems marine biologists are
confronted with in their efforts to
restore the native species to
their original habitat.
|Fly Fishing the Great Smoky Mountains National Park
The Park's stream with the
highest pH is probably
Abrams Creek. Much of its
water comes from water that
flows underneath Cades Cove.
Many of the streams in Great Smoky Mountains National Park are on the
acidic side of the pH scale. Water below the normal pH scale of 7.0, almost
always contains less aquatic insects than water that is average. Less
aquatic insects generally means there's less food for the trout. Less food
means the streams will have smaller trout.
When the unpolluted rain and snow falls from the sky it is pure and free from
minerals. It's slightly acidic and has a pH of approximately six. This does not
take into consideration acid rain which is a big factor in the pH level. This has
been a problem for the Smoky Mountains and many other places for that
matter. Reports are coming out saying the acid rain situation caused by air
pollution in the park is getting better.
As the water flows downhill, the pH will usually increase depending upon the
type of rocks, sand, gravel, and organic material (such as leaves and
vegetation) the water passes through. The PH of the headwater streams
varies from region to region in the Smokies depending on the plants and the
composition of the soil and rocks. Rain forest type terrain, such as is found
in the Appalachian Mountains, provides the water a different chemical
composition than the more barren slopes of the Rocky Mountains. If the
water passes through volcanic rock, it's going to remain acidic much longer
than water passing through a forest.
Those of you that have a swimming pool that you maintain are very familiar
with the pH of water. In this situation you don't want water that's on the
alkaline side of the scale because it supports the growth of the things you
have to clean from the sides and bottom of the pool Those of you that have
an tropical fish aquarium are also probably very familiar with pH. If water in
the aquarium gets off the desirable level very much you and the fish will
soon know it.
pH is not the only factor important for fish. It is just one of several. Facts are
where streams have a high pH value above 7.0, such as spring creeks, the
trout grow to much larger sizes than they do in water with a low pH value.
The different pH values of the water from its origin in the mountains to the
larger streams or rivers in the valleys supports different groups of aquatic
insects. The water temperature is generally higher in the lower sections of
the stream and this can also be a factor that affects trout in that it changes
the insect population. The speed of the water is also a big factor in
determining which aquatic insects exist.
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
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
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
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 species 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.
Copyright 2011 James Marsh
Brook Trout seem to be more tolerant of
acidic water than other species of trout. My
guess is that the char became that way over a
long period of time (thousands of years
maybe). I don't think they became tolerant of
the extra acid that got into the water when
construction workers cut a road through the
anakeesta rock formations in the park or when
man polluted the air to the point it caused acid
rain to occur.
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