An Inventory of THE FISHES OF JORDAN CREEK, Vermilion County, Illinois 



R. Weldon Larimore, Quenfin H. Pickering, and Leonard Durhann* 



Many streams and small rivers transect the up- 

 land prairies of Illinois. Most of them drain rich 

 agricultural lands and are strongly influenced by the 

 farming practices of surrounding areas. Some have 

 been dredged. Probably all of them receive large 

 amounts of surface water during periods of heavy 

 rainfall. Usually the runoff water carries a heavy 

 silt load, which causes the streams and rivers to 

 become very turbid for a period of days or weeks. 

 In some parts of Illinois, the streams are fed main- 

 ly by springs, in others mainly by drainage tiles. 



A considerable number of these streams and 

 small rivers support large populations of fishes, 

 including several species of importance to anglers. 

 In some parts of Illinois, stream fishing is a com- 

 mon practice, but in most of the state it is confined 

 to a comparatively few individuals who are some- 

 what secretive about the sources of their catches. 

 Consequently, the average Illinois angler thinks of 

 fishing in terms of lakes. 



Most of the fishery investigations on the 

 smaller streams of Illinois have considered princi- 

 pally the distribution of species as related to the 

 stream habitat (Forbes & Richardson 1920; 

 Thompson & Hunt 1930). The concept of managing 

 the stream habitat and the fishes of a stream for 

 the improvement of angling has received 

 little consideration. 



As a preliminary to the development of fish 

 management techniques for small streams, an inten- 

 sive study of the fishes of Jordan Creek, a tributary 

 of the Salt Fork of the Vermilion River in Vermilion 

 County, east central Illinois, was begun in July, 

 1950. This study has been almost continuous since 

 that time. The material included in this report is 

 largely an analysis of an intensive inventory of the 

 fish population made between July 25 and 

 September 5, 1950. 



Acknowledgments 



The investigation reported here is part of the 

 fisheries program of the Illinois Natural History 

 Survey and has been jointly supported by the 

 Survey and the Illinois Department of Conservation. 

 Dr. George \V. Bennett supervised the organization 

 of the project and offered valuable suggestions for 



this report. Mr. Sam A. Parr, Superintendent of 

 Fisheries, Department of Conservation, co-operated 

 in this program by arranging for funds to aid 

 the investigation. 



Methods and Procedure 



Field operations on Jordan Creek were begun 

 by a crew of two or three men during the last week 

 in July, 1950. Beginning at the mouth of the creek, 

 the crew worked each pool and riffle with an elec- 

 tric apparatus that stunned but did not kill the fish. 

 As the crew moved upstream, the pools were num- 

 bered and described. Continuous sampling was 

 stopped at a distance of 4.02 miles above the 

 stream mouth because sample collections indicated 

 that few if any game fish were present above 

 this point. 



The electric apparatus for stunning the fish 

 was operated from a portable 115- volt alternating 

 current generator. At the beginning of the opera- 

 tion, two hand-carried electrodes were used in a 

 manner described by Shetter (1947). Later an elec- 

 tric seine, a modification of that described by Funk 

 (1949), was used in all collecting. This electric 

 seine, 21 feet in length, allowed a complete sweep 

 of the stream, fig. 1, except in a few especially 

 wide pools. The difference in efficiency of these 

 two fish shockers was not determined. The elec- 

 tric seine, however, was faster to use because it 

 was effective over a greater area at one time. 

 Stunned fish were picked up in dip nets. The 

 quarter-inch mesh of the nets largely determined 

 the minimum size of fish collected. 



Game and pan fishes that were stunned by the 

 electrical current and collected were kept alive in 

 tubs and later released at the points of capture. 

 Prior to release, the total length of each of these 

 fish was recorded, scale samples were taken, and 

 one or more fins were clipped for later recognition 

 of the fish. Fin marks were changed at intervals 

 of about a quarter mile of stream distance. Weights 

 were taken of enough specimens to determine the 

 length-weight relationship for each species and to 

 allow an estimate of the weight of the fish that 

 were only measured for lengths. Fish other than 

 those considered as game and pan species were 



♦R. Weldon Latimote, Assistant .■\quatic Biologist, Illinois Natural History Survey; Quentin H. Pickering, at time of inventory, 

 Technical Assistant, Illinois Department of Conservation; Leonard Durham, at time of inventory. Technical Assistant, Illinois 

 Natural History Survey. 



