MICHIGAN (Cont. ) 



60. Increasing Productivity of Marl Lakes 



Additions of organic matter and inorganic fertilizers are made to marl soils 

 to deternnine the factors limiting the production of fish food organisms in marl 

 lakes. Methods of modifying marl lakes so as to increase their productivity 

 are being investigated. 



Began 1952, continuing; $2,657; Frank F. Hooper, Leader; reports avail- 

 able. 



Address inquiries to: As in No. 3 above. 



61. Bottom Fauna and Condition of Brown Trout in Houghton Creek 



The objective is to determine the effects of the Rose City sewer upon bottom 

 fauna and brown trout in Houghton Creek. 



Ogemaw County; began 1953, closed 1956; $759; Howard Cowing and Robert J. 

 Ellis, Leaders; reports available. 



Address inquiries to: As in No. 3 above. 



62. Headwater Lake Fertilization 



The objective is to determine the effect of fertilizing a headwater lake upon 

 the stream below. 



Hoffman Lake and West Branch of Sturgeon River; began 1954, to close 1957; 

 $4,555; Frank F. Hooper and Robert C. Ball, Leaders. 



Address inquiries to: As in No. 3 above. 



63. Weed Control in Fisheries Managennent 



The objective is to determine effect of control of aquatic vegetation on growth 

 of pan fishes in selected lakes. 



Began 1955, to close 1959; $9,109; Frank F. Hooper and J. E. Williams, 

 Leaders. 



Address inquiries to: As in No. 3 above. 



64. Establishment of Rooted Vegetation in Marl Lakes 



Through plantings of seeds and tubers attempts will be made to establish 

 rooted vegetation in marl lakes and effects of the experiment on fish population 

 will be followed. 



Fish Lake and Devoe Lake; began 1955, continuing; $4,555; Frank F. 

 Hooper, Leader. 



Address inquiries to: As in No. 3 above. 



65. Improver lent of Pike Spawning Habitat 



The purpose of the project is to discover requirements of pike for spawn- 

 ing and to devise and analyze methods by which spawning success may be im- 

 proved. 



Selected lakes; began 1950, to close 1960; $1,139; John E. Williams, Leader. 



Address inquiries to: As in No. 3 above. 



66. Experimental Fishing Regulations on Lakes 



Creel census, age, growth, and population studies are being used to de- 

 termine the effect of relaxed fishing regulations on 14 "experimental" lakes. 



Began 1953, to close 1960; $35,299; Kenneth E. Christensen, Leader; re- 

 ports available. 



Address inquiries to: As in No. 3 above. 



67. Hooking Mortalities - Trout 



The objective is to determine mortality to undersized trout through flie 

 use of plugs, spoons, spinners, and other baits. Fish, both hatchery reared 



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