MINNESOTA (Cont. ) 



6. Effect of Stream Improvement on Trout Populations and Fishing. 



The value of stream improvement of the usual type to survival of planted trout, 

 stream carrying capacity, and fishing yield of trout is being investigated. 



Split Rock River in northeastern Minnesota; began May 1950, planned for 5 y^ars; 



John Hale, Aquatic Biologist; limited number of progress reports available. 

 Address correspondence to: John B. Moyle, Supvr. , Fisheries Research Unit, 



355 Shubert Bldg. , St. Paul, Minn. 



7. Relationship of Net Catches to Size and Structure of Fish Population and Angling 

 Harvest. 



A study to obtain better methods for evaluation of fish management procedures and for 

 interpreting lake survey data is being carried out on 12 lakes scattered over the 

 State. Some of the desired information will be obtained by means of creel censuses 

 (FA project F-4-R). Evaluation of the effectiveness of various types of nets for 

 sampling populations, and the relationships betxween net catches, angling harvest, 

 fish populations and environmental factors are being examined. Data on fish mor- 

 tality and interspecific connpetition are being gathered. 



Began December 1951, planned for 4 years; Creel census report for 1952 available 



in limited numbers. 

 Address correspondence to: John B. Moyle, Supvr., Fisheries Research Unit, 



355 Shubert Bldg. , St. Paul, Minn. 



8. Lake Inventory and Mapping. 



Detailed information on physical, chemical, and biological characteristics of 

 Minnesota lakes is being gathered for use in fish management. 



Statewide; began in 1931, continuing; Charles R. Burrows, Aquatic Biologist. 

 Address correspondence to: John B. Moyle, Supvr. , Fisheries Research Unit, 

 355 Shubert Bldg. , St. Paul, Minn. 



University of Minnesota, Department of Zoology 



1. Distribution and Intraspecific Variation in Minnesota Fishes. 



Investigations are under way to determine the distribution of fishes in various types 

 of waters in Minnesota and to discover if any structural differences occur in the 

 same species in different drainages. 



Minnesota; began April 1952, planned for 2 years; $3,000. 



Address correspondence to: James Underhill, Project Leader, Dept. of Zoology, 

 Univ. of Minn. , Minneapolis, Minn. 



2. Toxicity of the Eggs of the Longnose Gar. 



The project is concerned with the effect of feeding eggs of longnose gar to various 

 animals including fishes, and proposes to isolat3 and determine the toxic agent 

 present in the eggs of the longnose gar. 



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