IOWA (Cont. ) 



and non-game fishes, the extent of exploitation, length-weight relationships, 

 and species connposition of the catch. This was a joint effort of the member 

 states in the Upper Mississippi River Conservation Committee. 



Wisconsin and Illinois Conservation Departments cooperating; began June 

 1956; $4000; R. E. Cleary, Leader; reports available. 



Address inquiries to: E. B. Speaker, as in No. 7 above. 



11. A Population Study of Walleyes 



A long-term walleye fry stocking experiment now in its twelfth year is 

 coupled with this study. In addition to the fry, a limited number of fingerlings 

 have been stocked from nursery units. The progress of the walleye population 

 has been followed by extensive gillnetting during the spawning run and through 

 the summer surveys with 500 feet of l/4-inch seine. A total walleye popula- 

 tion estimation of this lake will be made again in 1956. 



Began April 1944, continuing: $500; E. T. Rose and Tom Moen, Leaders; 

 reports available. 



Address inquiries to: E. B. Speaker, as in No. 7 above. 



12. Rough Fish Studies 



This project involves a general collection of data on carp, buffalo, sheeps- 

 head, and gizzard shad. The primary portion of this study has concerned food 

 habits, but data have also been collected on ecology, age and growth, repro- 

 duction, sexual maturity, number of eggs per fish and condition factors in an 

 over-all effort to determine the interrelations existing between rough fish and 

 their environment and between rough fish and game fish. 



Began January 1946, continuing; $1, 000; Tom Moen, Leader; reports 

 available. 



Address inquiries to: E. B. Speaker, as in No. 7 above. 



13. The Value of Stocking Walleyes in Iowa Streams 



The object of this investigation is to study the possibility of supplementing 

 our stream fisheries by the introduction of hatchery-reared walleyes. Stock- 

 ing is on an alternate year basis. Collections of scales are made to determine 

 whether or not the majority of fish caught come from the years in which walleyes 

 are planted. 



Iowa; began May 1950, continuing; $500; R. E. Cleary and Harry M. Harri- 

 son, Leaders; reports available. 



Address inquiries to: E. B. Speaker, as in No. 7 above. 



14. Factors Affecting Smallmouth Bass Production in Northeastern Iowa 



This project involves a multi-phase study of the life history and ecology 

 of smallmouth bass in streams. Data are gathered annually on the number of 

 nests seen per mile, condition and location of nests, effect of changed environ- 

 ment, effect of stream flow, turbidity, number of fingerlings per 500 feet of 

 seining, age and growth, and bottom fauna. Effort is also being made to cor- 

 relate good and poor natural hatches with age and survival data on minnows 

 to attempt to discover forage indicator species which will give accurate in- 

 sights into annual reproduction success of the smallmouth bass. 



Began May 1949, continuing; $2000; R. E. Cleary, Leader; reports avail- 

 able. 



Address inquiries to: E. B. Speaker, as in No. 7 above. 



15. A Study of Hatchery Techniques at Spirit Lake, Clear Lake, and Lansing. 



The project was set up to study general hatchery procedures as they are 

 concerned with the hatching and stocking of walleye and northern pike. Basic 



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