. Bulletin. Natural history; Natural history. 92 ILLINOIS NATURAL HISTORY SURVEY BULLETIN disease is not an important factor affecting the abundance of fishes in the Kaskaskia, just as in other streams, since there is a wide variety of diseases which probably take a small but steady toll of fishes, with only an occasional outbreak which may kill off large enough numbers to be noticed. Dead fishes are quickly devoured by scavengers both in water and on land, and diseased or injured fishes with slow or erratic movements are easily caught by Fig. 9.âKaskaskia River 2 miles above the m
. Bulletin. Natural history; Natural history. 92 ILLINOIS NATURAL HISTORY SURVEY BULLETIN disease is not an important factor affecting the abundance of fishes in the Kaskaskia, just as in other streams, since there is a wide variety of diseases which probably take a small but steady toll of fishes, with only an occasional outbreak which may kill off large enough numbers to be noticed. Dead fishes are quickly devoured by scavengers both in water and on land, and diseased or injured fishes with slow or erratic movements are easily caught by Fig. 9.âKaskaskia River 2 miles above the mouth, July, 1930. Pollution.âFinally, abundance of fishes is influenced by the amount and kind of pollution which a stream has to bear. The sewage load of the Kaskaskia, or Okaw, is small and has little effect except during periods of low water, when some stretches, especially in summer, may become heavily polluted. For example, a septic condition existed below Carlyle in July and August of 1930. The untreated domestic sewage which goes into the river at Carlyle is augmented by wastes from a strawboard factory and a milk plant. As a result of this pollution, for a distance of at least 25 miles down- stream there was no dissolved oxygen in the water. Thousands of fishes were killed, and all the bottom animals, such as mussels and snails, must have perished also. The water was black, a layer of black sludge several inches thick covered the bottom and a strongly putrescent odor was ap- parent, even at some distance from the stream. Normally this, section of the river is a very productive one^- -^snart 'â :a zc About 100,000 people live in the Kaskaskia basin in towns and cities. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Illinois. Natural History Survey Division. Urbana, State of Illinois, Dept. of Regi
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