duction but have given no turbidity readings (Smith, 1940j Chandler, 1942a; 

 Swingle, 1949; Fessler, 1950; and numerous others) o There is, in fact, a 

 notable paucity of data relating fish growth and reproduction to measured 

 turbidities o The only known record was made in an early work by Schneberger 

 and Jewell (1928) in studying factors affecting pond fish production in 

 Kansas. They observed that, other things being equal, the fish production 

 in ponds was directly related to clearness of the water for turbidities 

 above 100 ppm, but that other factors become more influential at lesser 

 turbidities. 



Various writers have noted the effects of turbidity and siltation 

 on lesser aquatic organisms. Some assert that turbidity and associated 

 sedimentation often limit the production of algae, as well as higher aquatic 

 plants (Chandler, 1940, 1942a, 1944; Meyer and Heritage, 1941; Langlois, 1941, 

 1945; Chandler and Weeks, 1945; Moen, 1947). Others credit the same pro- 

 cesses with eliminating many bottom organisms important as fish food (Ellis, 

 1936, 1937, 1944; Sumner and Smith, 1940; Smith, 1940; Munns, 1948; Hambric, 

 1953). Perhaps the widest attention has been given to the effects of tur- 

 bidity in excluding light from the aquatic environment and the critical 

 limitations thereby imposed on aquatic organisms (Ellis, 1931, 1936, 1937, 

 1944; Welch, 1935; Chandler, 1940, 1942a, 1942b, 1944; Doan, 1942; Shaw 

 and Maga, 1943; Meyer, Bell Thompson and Clay, 1943; Chandler and Weeks, 

 1945; Irwin, 1945, 1948; Moen, 1947; Munns, 1948; Aldrich, 1949; Hall, 

 1952; Berner, 1951; Hambric, 1953; Claffey, 1955). 



METHODS AND PROCEDURES 



The present problem was studied in farm ponds, in partially controlled 



