Lake area, care was taken to keep the DDT out 

 of the stream. As a result not enough DDT 

 entered the stream, either year, to cause an 

 appreciable kill of aquatic organisms. 



The Brasstown Bald area, on the other 

 hand, was treated without special precaution and 

 a sufficient amount of DDT entered the creek in 

 1959 to cause a serious depletion of the bottom 

 organisms. The three sampling stations on this 

 stream showed reductions of 65 percent, 80 per- 

 cent, and 40 percent in total number of bottom 

 organisms. Mortality reduction was exagger- 

 ated by emergence . Drift samples indicated 

 that the bottom organisms were affected almost 

 immediately by the DDT, with the greatest num- 

 ber of organisms appearing in drift samples 

 one-half hour after treatment. Thereafter, the 

 numbers decreased at each sampling and had 

 diminished 85 percent at the end of four hours. 

 Although all forms of aquatic insects were af- 

 fected by the DDT, only the Chironomidae, 

 Tabanidae, and Noteridae appeared to be com- 

 pletely eliminated. Populations in this stream 

 declined for one month after treatment, and 

 then began a gradual increase. At the end of 

 four months bottom samples indicated a com- 

 plete recovery at all stations, in terms of total 

 numbers of organisms. 



In 1960 the vegetation was somewhat ad- 

 vanced and this may have prevented some DDT 

 from entering the stream . 



ACKNOWLEDGEMENTS 



The author is indebted to Bill Jackson 

 and Dale Vandenburg of the U. S. Forest Serv- 

 ice for assistance in the field program, and to 

 Dr. O. B, Cope of the Bureau of Sport Fisheries 

 and Wildlife in preparation of the report. 



LITERATURE CITED 



Anderson, Richard O., and Frank F. Hooper 

 1956. Seasonal abundance and production 

 of littoral bottom fauna in a southern 

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 American Microscopical Society, 

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Ball, Robert C, and Don W. Hayne 



1952. Effects of the removal of the fish 

 population on the fish-food organisms 

 of a lake. Ecology, vol. 33, No. 1, 

 pp. 41-48. 



Cope, O. B., and Barry S. Park 



1957. Effects of forest insect spraying on 

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 Project Report for 1956, pp. 1-53. 



Gjullin, C. M., O. B. Cope, B. F. Quisenberry, 

 and F. R. DuChanois 



1949. The effects of some insecticides 



on blackfly larvae in Alaskan streams. 

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Larrimore, R. Weldon, William F. Childers, 

 and Carlton Heckrotte 



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Hoffmann, CM., and A. T. Drooz 



1953. Effects of a C-47 airplane applica- 

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 50, No. 1, pp. 172-188. 



Hoffmann, CM., and E. W. Surber 



1949. Effects of an aerial application of 

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1945. 



gressive Fish-Culturist, vol. 11, No. 

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Effects of an aerial application of 

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 organisms in Back Creek, West Vir- 

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Muller, Karl 



1954. Investigations on the organic drift in 

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 133-148. 



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