IOWA (Cont. ) 



10. 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. Stocking 

 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. 



Streams, northeast quarter of State; began May 1950, continuing; R. E. 

 Cleary and Harry M. Harrison, Leaders. 



Address inquiries to: E. B. Speaker, as in No. 4 above. 



11. Factors Affecting Smallmouth Bass Production in Northeastern Iowa. 



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

 the smallmouth bass in 17 test streams in the area. Data is gathered annually 

 on the nests seen per mile, condition and location of nests, effect of changed 

 environment, effect of stream flow, turbidity, number of fingerlings per 500 

 feet of seining, age and growth data, quantitative bottom fauna. Effort is also 

 being made to correlate good and poor natural hatches with age and survival 

 data on minnows to attempt to discover forage indicator species which will give 

 accurate insights into annual reproduction success of the smallmouth bass. 



Northeastern Iowa; began May 1949, continuing; $2,000; R. E. Cleary, Leader. 



Address inquiries to: E. B. Speaker, as in No. 4 above. 



12. Modified Voluntary Creel Census. 



This project was started to give an insight into the per hour take of especially 

 picked anglers who are deemed "experts" and who fish primarily in the flowing 

 waters of northeastern Iowa. The contacts are picked on a fixed ratio from each 

 county and serve to furnish us with season catch data on a weekly report basis. 

 Their data indicate a measure of the available crop, season take, selectivity of 

 stream, and to correlate against test netting results. 



Streams of northeastern Iowa; began April 1950, continuing; $1, 000; R. E. 

 Cleary, Leader; reports available. 



Address inquiries to: E. B. Speaker, as in No. 4 above. 



13. 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, reproduc- 

 tion, 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. 



Natural lakes of northwest Iowa; began January 1946, continuing; $1, 000; 

 Tom Moen, Leader; reports available. 



Address inquiries to: E. G. Speaker, as in No. 4 above. 



14. Techniques of Fish Surveys in Streams. 



This project involves a study of the effectiveness of various types of gear 

 used to make stream and river surveys. At present, special emphasis is placed 

 upon determining the best gear suited to the rivers and streams of the type 

 found in Iowa and at what time of year and under what conditions they work best. 

 The types of equipment under observation include the conventional electrical gear, 

 traps and seines of various design used under a variety of conditions, and the 

 use of several instruments to drive fish into traps. In addition to this, studies 

 are underway to determine the possibility of making stream surveys under ice. 



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