March, 1963 Larimore & Smith: Fishes of Champaign County 



359 



number of species per station increased 

 downstream ; the actual number of fish 

 per unit area decreased downstream ; and, 

 with a decrease in the number of individ- 

 uals downstream, there was a correspond- 

 ing increase in their average size, so that 

 the total amount of fish flesh per unit 

 area was nearly constant. Thompson & 

 Hunt's statement that fishes exhibit fre- 

 quencies of occurrence that vary with 

 stream size in a consistent and definite 

 manner for each species was not substanti- 

 ated with the 1959 data. Their hypothesis 

 that the amount of fish flesh per unit of 

 water was directly related to fertility of 

 the water was neither confirmed nor dis- 

 proved by the 1959 data, probably because 

 all streams of the county were of nearly 

 equal fertility. 



14. The degree of stream pollution in 

 Champaign County was greater in 1928 

 than in 1899, and greater in 1959 than in 

 1928. Although certain types of pollutants 

 common in 1899 and 1928 no longer ex- 

 isted in 1959, other types had replaced 

 them. The large and increasing volume of 

 treated effluents limited aquatic life in 

 many areas of Champaign County streams 

 at the time of the third survey. Pollution 

 had caused a decline, even elimination, of 

 fish in some reaches. 



15. In 1959, chronic pollution in 

 Champaign County was found to occur 

 in the Boneyard, parts of the East Branch 

 and West Branch of the Salt Fork, the 

 lower Salt Fork, Copper Slough and 

 Phinney Branch, the upper Sangamon, and 

 the upper Kaskaskia. Some of these areas 

 had been polluted for many years; others 

 had recently become polluted. 



16. Champaign County streams are en- 

 riched by natural soil fertility and a vari- 

 ety of introduced substances. Evidence 

 was found in 1959 that certain fish popu- 

 lations were benefiting from enrichment. 

 Slight changes in chemical balance and 

 concentration may quickly convert en- 

 riched areas to polluted ones. 



17. Champaign County contains a con- 

 siderable amount of water useful for fish- 

 ing. In addition to the streams, there are 

 farm ponds, artificial lakes, and fee-fish- 

 ing ponds available. Public access to the 

 fishing sites is generally adequate, al- 

 though streams are privately owned and 

 landowners' permission must be obtained. 

 Approximately 20 of the 90 species of fish 

 known in the county are commonly taken 

 by angling. Noncommercial minnow sein- 

 ing for bait is a justifiable use of the local 

 fauna and does not jeopardize local min- 

 now populations. 



