BiOLOGTrAL Survey — Genesee Ri\t:r 39 



consequently are well adapted to live in situations Avhere the 

 food supply is rich regardless of the oxygen content of the water. 

 Rat-tail mag'g'ots also are able to live in badly polluted waters 

 where the organic contents are high and the oxygen supply very 

 low or entirely absent. Sludge worms (Tuhifex) likewise thrive 

 in such situations. The i:)resence of any or all of these organisms 

 at once indicates that the water is polluted to the extent of killing 

 or excluding all fish and other fresh water organisms. The 

 presence of blood worms {Cliironomidae) still indicates consider- 

 able pollution, even to the point of danger to fish life, but their 

 presence also indicates that the stream is beginning to recover 

 from the polluting substances, and that there is at least a small 

 amount of oxygen present in the water. Milk-polluted streams 

 often produce a luxuriant growth of green plants, particularly 

 pondweeds (Pofamogetons), duck weed (Lemna) and others. 

 These are of great benefit to the stream for they utilize some of 

 the waste products and help to restore the necessary oxygen of 

 the water. Blue-green algae (Oscillatoria) indicate a considerable 

 amount of pollution present and serve as indicators of heavy 

 organic pollution. An account of one or two typical examples of 

 milk ]:)ollution in the Genesee valley will serve to illustrate the 

 effect of these wastes upon fresh water streams. 



The Merle-Soule plant at Bliss, X. Y., on Wiscoy creek receives 

 more than 50,000 pounds of milk per day and empties its wastes 

 into Wiscoy creek. The milk wastes are first run into concrete 

 vats and are then chemically treated by the lime-precipitation 

 method. In this manner much of the nitrogenous material is pre- 

 cipitated as sludge and kept from going into the stream. The 

 supernatant liquid is then drawn off and run into a filter and from 

 there it is emptied into Wiscoy creek. This treated waste still 

 retains a considerable amount of nitrogenous substances and is, 

 therefore, capable of polluting the water to a considerable degree, 

 especially where there is insufficient stream flow to insure proper 

 dilution. 



Wiscoy creek is a cold water stream and represents one of the 

 finest trout streams in the Genesee valley. It was, therefore, of 

 particular interest to determine what the effect of this treated 

 milk waste had upon the stream. Beginning at the point of 

 entrance of this waste into the stream, the stream bed was fairly 

 covered with sewage fungus, a condition which extended down- 

 stream a distance of about half a mile. Within the fungus growth 

 were found numerous snails and a very large number of midge 

 larvae (Chironomidae). So abundant were they that a sample 

 of 24 cubic centimeters of the fungus growth contained by actual 

 count 333 midge larvae and 3 snails. These midge larvae 

 constitute a choice fish food. Fortunately Wiscoy creek has a 

 rapid and large enough stream flow to dilute the milk wastes. 

 The presence of brown trout and other fish indicated that the 

 stream apparently had not suffered from the milk wastes, and 

 perhaps had been benefited by them to the extent of furnishing 



