Volume 52, Number 1, May 2005:
Stream Ecology

Text-only version


ISSUE HOME PAGE

ABOUT THIS ISSUE
- about KSN
- about the author

IN THIS ISSUE
- introduction
- stream communities
- physical characteristics of streams
- biological features of streams
- common groups of stream organisms

Stream Ecology
by Carl Prophet

INTRODUCTION

It is well known that ecological resources essential to the maintenance of life on this planet, such as water, oxygen and carbon, are recycled again and again over time. If the movement of water through the environment is traced, its path ultimately returns to the starting point. The descriptions of this path and the main biological uses and physical processes that happen along the way are known as the water cycle.

The oceans are the main reservoirs for the world's water supply. The physical processes, evaporation and precipitation, are driving forces for this cycle. Water evaporates from the sea, and the water vapor is carried along by atmospheric currents. When the vapor condenses, precipitation in the form of rain, ice or snow takes place. Only a fraction of the total precipitation that occurs during the course of a year takes place over land, and that amount is not distributed evenly. The moisture that does not immediately soak into the soil becomes runoff to nearby streams in a given drainage basin. The water eventually flows into a major river which drains into the ocean. The journey is completed and the cycle is repeated. Numerous other events and processes are involved in the water cycle, but the focal point here is that in the water cycle, streams are the vital link between land and sea.

Historically, streams and rivers played an important and vital role in the western expansion and development of the United States. Rivers often served as highways for early explorers and adventurers entering territories previously unsettled by European colonists, and later they were used to transport commerce between the frontier settlements
and the large population centers in the East. Today, huge quantities of goods and raw materials continue to be moved on many of our nation's large rivers by barge trains and even oceangoing ships. Flowing water has long been used to provide power. Before the days of steam and electricity, the force of flowing water was used to power the mills that ground our grain. Early maps often identified the locations of mills, and remnants of mill dams and races can still be found on some streams in Kansas. Today, in many parts of the United States flowing water is used to generate electricity. Dams have been constructed on some of our nation's large rivers creating giant lakes for the storage of tremendous volumes of water. The impounded water is released periodically to drive huge turbines to generate electricity. In Kansas, electricity is generated primarily by the use of nuclear and fossil fuels, but water is still necessary for the generating process.

Our rivers and streams have served other important purposes. Water is essential for life. To survive and flourish the inhabitants of an area must have a nearby dependable source of water. It is therefore not surprising that as settlers moved into new territories their towns were often established on or near streams. This was certainly true in the case of the settlement of the Kansas Territory. There were few sources of surface water on the Kansas prairie other than streams. Sadly, as some communities grew the nearby streams became used as a convenient and inexpensive way of disposing of untreated human and industrial wastes. Ultimately, such practices had a devastating impact on the ecology of the receiving streams. Such practices continued well into the middle of the Twentieth Century until state and federal environmental laws and enforcement began to reduce the problem. While important progress has been made, the battle to improve water quality in streams continues, and each of us has a role and shares the responsibility for accomplishing this goal.

There is little doubt that our rivers and streams are an important natural resource which have many values and uses, but one value of a stream that is frequently overlooked is its aesthetic value. Is there any person who has visited a stream setting and paused long enough to take in the scene who has not been struck by the unique natural beauty and the relaxing sounds of their surrounding? Sit quietly by a stream for a few minutes. Listen. The sounds of birds singing and water trickling over a shallow rocky bottom are relaxing and peaceful. Look closely and perhaps you will see some plant or animal new to you. Is there a value to these experiences? Of course there is.

Photo caption: Old mill dam at Drury, Kansas. Remnant of mill race can be seen on far side of stream.