IOWA (Cont. ) 



chemistry are also obtained. Electro-fishing devices, both AC and DC, will 

 be used to supplement nets and seines in the population studies in 1954. Infor- 

 mation is recorded on forms and recommendations presented for possible im- 

 provement of fishing. 



Northern half of State; began July 1940, continuing; $5, 000; Earl T. Rose, 

 Leader; reports available. 



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



6. Artificial Lakes Survey. 



A continuing inventory is nnaintained in the form of an annual netting survey 

 and limited limnological investigations of the artificial lakes. Although special 

 emphasis is placed on the relative abundance of each species and extent of re- 

 production, other items such as age and growth, abundance of bottom fauna, 

 extent and species of vegetation, turbidity, and extent of chemical and thermal 

 stratification are determined. 



Statewide; began September 1947, continuing; $1,500; Tom Moen, Leader; 

 reports available. 



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



7. Creel Census. 



Principal objective of this project is to determine fishing success in the 

 major lakes of Iowa. Annual sampling of anglers is conducted from May 15 

 to July 1, on five lakes in northern Iowa, and on a year-round basis at Spirit 

 and Okoboji Lakes. Comparisons of tabulated total catch by species and unit 

 effort are made from season to season to indicate trends and evaluate manage- 

 ment practices. 



Spirit, East and West Okoboji, Lost Island, Storm, Clear and Blackhawk 

 Lakes; began May 1946, continuing; $4,000; Earl T. Rose, Leader; reports 

 available. 



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



8. A Population Study of Walleyes of Spirit Lake. 



A long-term walleye fry stocking experiment now in its sixth 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 rvm and through the 

 sunruner surveys with 500 feet of l/4-inch seine. A total walleye population 

 estimation of this lake will be made again in 1954. 



Spirit Lake; began April 1944, continuing; $500; E. T. Rose and Tonn Moen, 

 Leaders. 



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



9. A Study of Hatchery Techniques. 



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

 cerned with the hatching and stocking of yellow pike-perch and northern pike. 

 Basic data is collected on production (total number of eggs), number of eggs 

 per quart (size), size at various stages of development, fertility, temperatures, 

 and numbers and sex of fish handled. Some experimental work is being carried 

 on in methods of handling both eggs and fish. 



Spirit Lake and Clear Lake Hatcheries; began April 1946, continuing; $500; 

 Tom Moen, Leader. 



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



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