THE DISTRIBUTION AND FOOD OF THE FISHES OF 

 THREE WISCONSIN LAKES IN SUMMER 



INTRODUCTION 



Except for the "reconnoissance" of Reighard (1915), little 

 has been published on the ecology of lake fishes. For several 

 years the writer has been studying the distribution, food, and 

 parasites of the fishes in Wisconsin lakes. In 1916 routine 

 catches were made in Lake Wingra, which is small and shallow 

 (Pearse and Achtenberg, 1920). During the summer of 1919 

 the fishes in Green Lake and Lake Mendota were investigated 

 (Pearse, 1920). The former lake is remarkable for its depth and 

 clearness, the latter for the stagnation of its deeper parts during 

 the summer. In 1920 work was done on three lakes: Lake 

 Pepin, which is a part of the Mississippi River and yet shows 

 typical lacustrine conditions; Lake Michigan, representative of 

 primitive lake habitata for the St. Lawrence drainage; and Lake 

 Geneva, the clearest and deepest lake on the Mississippi drain- 

 age. 



The study of the ecology of the Wisconsin lake fishes has 

 progressed to such a stage that it is now possible to compare the 

 fishes in six different types of lakes. Though this paper deals 

 primarily with the three lakes studied during 1920, it also makes 

 comparisons between all the lakes investigated, and thus gives 

 a general summary of the work. Table I contains data relating 

 to all the lakes considered. The lakes are arranged according 

 to the total volume of water. 



During the summer of 1920 the three lakes studied were un- 

 der observation as follows: At Lake Pepin from June 20 to 

 July 25 headquarters were made in a shanty owned by Mr. 

 Jean Hogue on a sandy point extending between the Mississippi 

 River and the slews north of the mouth of the Chippewa River. 

 This location was close to the deepest parts of the lake. On 

 Lake Michigan headquarters were in Mr. A. C. Kalmbach's 

 fish market, Sturgeon Bay, from July 17 to 27. Three trips 



