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muddiest ponds in locations subject to the most severe erosiono 



SUMMARY 



1. The results of a two-year study of the effects of turbidity on fish 

 and fishing in Oklahoma ponds and large reseryoirs is presented. The 

 project was co-sponsored by the Outboard Boating Clxib of America, the 

 Sport Fishing Institute, and the Oklahoma Game and Fish Department. 



2. Pond work involved (1) a study of growth and reproduction of large- 

 mouth bass, bluegill and redear sunfish, and production of plankton 

 in 33 experimentally stocked farm ponds of varying degrees of tur- 

 bidity, and (2) a study of growth of largemouth bass, bluegill and 

 channel catfish in artificially muddied hatchery ponds. 



3. Large reservoir work involved a comparison of growth, reproduction 

 and relative abundance of fishes, plankton production, and fishing 

 success in a clear and a turbid reservoir, plus comparisons with 

 other reservoir data„ 



4. At the end of two growing seasons, the average total weight of fish 

 in clear farm ponds was approximately lo7 times greater than in ponds 

 of intermediate turbidity and approximately 5.5 times greater than in 

 muddy ponds. Differences were due to faster growths by all species 

 and to greater reproduction in clear ponds, particularly by bluegills 

 and redear sunfish. 



5. Of the 3 species used in farm ponds, largemouth bass were most affected 

 by turbidity in both growth and reproduction. Redear sunfish appeared 

 less retarded in growth than did bluegills during the first year, but 

 the two sunfishes appeared equally restricted in both growth and 



