352 U.S. BUREAU OF FISHERIES 



COOPERATIVE INVESTIGATIONS OF WISCONSIN LAKES 



For many years the Bureau has cooperated with the Wisconsin 

 Geological and Natural History Surve}^ in linmological investiga- 

 tions of both fundamental and practical value on the lakes of north- 

 ern Wisconsin. The Bureau's share in the cooperative enterprise 

 consisted of modest financial support, the planning and technical 

 supervision being provided by Drs, E. A. Birge and Chancey Juday 

 of the State organization. 



In 1933 the Wisconsin Geological and Natural History Survey 

 received financial assistance for these cooperative investigations from 

 the United States Bureau of Fisheries, Wisconsin Conservation De- 

 partment, Alumni Kesearch Foundation, and Thomas E. Britting- 

 ham, Jr. 



The Survey's Trout Lake Laboratory vras opened on July 1, and 

 work was continued until September 9. The physical, chemi€al, 

 and part of the biological investigations were discontinued on Aug- 

 ust 31, but the plankton and fish researches were continued into 

 September. 



The field party consisted of the following individuals: H. C. 

 Baum, E. A. Birge, S. X. Cross, A. D. Hasler, K. Hunt, C. Juday, 

 K. R. Langford, W. E. Militzer, E. Schneberger, H. A. Schomer, 

 John Schreiner, W. A. Spoor, and L. R. Wilson. Dr. V. W. Meloche 

 of the Department of Chemistry spent the greater part of July and 

 August at the laboratory making a, special study of some of the 

 chemical problems involved in the investigations. Nine of the 14 

 members of the field party were working on problems which had a 

 direct bearing on the fish life of the lakes. In addition to the field 

 party, R. J. Allgeier was engaged in making analyses of lake resi- 

 dues in the chemical laboratory of the University of Wisconsin. 



In the earlier years of these investigations, a general survey of 

 the lakes of northeastern Wisconsin was made; it included one or 

 more visits to some 530 different bodies of water. This survey was 

 made for the purpose of obtaining some idea of the physical, chem- 

 ical, and biological status of the lake waters of this district. 



The general survey was completed in 1930 and since that time the 

 investigations have been limited chiefly to six lakes representing the 

 different types found in the district. These studies have had as their 

 main objective the physical, chemical, and biological conditions for 

 fish life in these lakes; the work on the fishes themselves has dealt 

 with the kind and quantity of food eaten by the various species, the 

 number and kinds of parasites harbored by them, and the rat? of 

 growth of the more common species in the different lakes. During 

 the summer of 1933 another fish problem was added to these, namely, 

 the determination of the total fish population of some of these lakes. 

 Such information is necessar_y for a study of the fish production 

 and of the fish-carrying capacity of a lake. It will also serve as a 

 basis for experimental work relating to the increase of the carrying 

 capacity of a lake by the use of artificial fertilizer. It will also 

 have a bearing on the problem of stocking a lake with fish. 



The details of the program and the results of the year's work are 

 not presented here because of lack of space but may be consulted in 

 the regular reports of the Survey and in the following publications: 



