highest pH is probably
Abrams Creek. Much of its
water comes from water that
flows underneath Cades Cove.
pH meter:
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 finding bass.
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.
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 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 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 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
