Introduction
The Wakarusa River rises in the eastern edge of the Flint Hills and flows approximately 50 miles in an easterly direction and empties into the Kansas River near Eudora; with its tributaries, the Wakarusa drains 458 square miles in parts of Wabaunsee, Shawnee, Osage, and Douglas counties of northeastern Kansas (Fig. 1). The average gradient is 6.3 feet per mile. Turbidity is consistently more than 100 ppm in the lower portions of the mainstream and major tributaries, but is usually lower in the upper portions of tributaries. The channel of the mainstream is intrenched in its own alluvium (Dufford, 1958:36) and has high, muddy banks and mud- or sand-bottom; the upper parts of tributaries have lower banks and bottoms of gravel, rubble, or bedrock, although a few (such as Cole Creek) have areas of sandy bottom. A fringe forest of deciduous trees occurs along most streams. The topography and geology of the area have been discussed by Todd (1911), Franzen and Leonard (1943), and Dufford (1958).
The five-year period prior to 1957 was the driest in the 70-year history of weather-records in Kansas (Metzleret al., 1958). Streams throughout the Wakarusa Basin suffered intermittency and, according to Mr. Melvon H. Wertzberger, the local Work Unit Conservationist with the Soil Conservation Service, many of them dried completely or contained only a few widely-scattered, stagnant pools. The effect of the drought on stream-flow at the mainstream gaging station 2.1 miles south of Lawrence is presented in Table 1.
According to the Division of Sanitation, Kansas State Board of Health, no untreated domestic sewage or industrial waste is discharged into the Wakarusa River System at this time.
The Wakarusa Watershed Association is in the preliminary stages of establishing a watershed control project in the basin. Objectives of the project are the improvement of land-use practices and the construction of several headwater retention structures. Such a program should have a long-range effect on the physical and biological characteristics of the streams of the basin. With this in mind we think it important to document the nature of the present fish-fauna and to attempt a historical résumé of the fauna, based on collections made in the past sixty years.