Tip #24: Learn to Read the Water

Posted by under General Tips, Pics and Pointers

Fish will behave differently depending on certain water conditions that change depending on what season it is. This includes the temperature of the water, what the weather is like, and the volume of the water. If you want to become a successful fly fisher you’ll have to learn how to read the waters where you’re fishing.

Some of the things that you’ll discover as you learn to read the water are (1) during non-feeding periods, fish can still be encouraged to strike if they are in a deep pocket of water, and (2) when fish are feeding they are usually found in the shoreline of runs of pools and in moderate water pockets.

Water chemistry plays a big part in the health of fish, the location where they are found, and how successful you are at catching the big one. One of the most important aspects of water chemistry is pH. In scientific terms pH can be defined as: the negative log molar concentration of hydronium ions in the water. In simple language pH is the measure of the acidity or basicity in the water.

pH is typically measured on a scale of 1 to 14. A pH of 7 is considered to be neutral. pH totals of less than 7 are acidic while a measure of over 7 is considered basic.

Most fish are able to tolerate a wide range of pH in the waters where they live. This is because they have the ability to regulate their internal levels of pH. This is accomplished by the fish constantly adjusting the ratio of bases and acids within their systems. They make these adjustments by expelling any excess acids in the urine and also by controlling their breathing.

The faster a fish breathes the faster carbon dioxide leaves the blood, thus raising the level of pH in the blood. However, most fish are eventually tired out by this constant regulating of their system. If the fish lives for too long in an environment that is too acidic or too basic it will become unable to manage its own system chemistry. When this happens the fish will stop feeding and eventually die.