FISHES OF THREE WISCONSIN LAKES 13 



Considering all the evidence, the following peculiarities may 

 be pointed out regarding the fish fauna of Lake Pepin, which 

 differs from other deep Wisconsin lakes studied in its intimate 

 association with a great river, its turbidity, and its lack of 

 marked thermal stratification in summer. In deep water the 

 hackleback sturgeon is the moot abundant fish during the sum- 

 mer and the yellow perch is rare or absent. In winter dogfish, 

 carp, wall-eyed pike and other fishes frequent the deep water. 

 The log perch is the dominant small fish alongshore. There 

 are many species present in numbers which are not typical lake 

 fishes but ecologically belong in rivers i.e., quillbacks and river 

 carp, mooneye, channel cat, buffaloes, red-horses, spoonbill, 

 skipjack, sauger, hackleback, etc. The greatest number of 

 species and individuals is found in the shallowest water, the 

 population of the five meters just below the surface exceeding 

 that of any other five-meter zone, except that of the zone from 

 10 to 15 meters where the deep and shallow water fishes over- 

 lap. 



DISTRIBUTION OF FISHES IN LAKE MICHIGAN 



The shores of Lake Michigan in the region of Sturgeon Bay 

 and the Sturgeon Bay Canal are rocky or sandy and the shores 

 in the Bay itself are sandy. At the head of the Bay there are 

 several large patches of rushes (Scirpus) and a couple of small 

 swampy areas. Table III gives the catch per hour in the writer's 

 gill nets at various depths. The greatest variety of species was 

 caught in the first five meters below the surface, but the largest 

 number of individuals was caught at depths of 5 to 10 meters. 

 The number of species caught in each stratum was as follows: 

 0-5 m., 7; 5-10 m., 4; 10-15 m., 1; 15-20 m., 3; 25-30 m., 2. 

 The black bullhead, carp, and pumpkinseed do not range below 

 five meters; the rock bass and pickerel extend from the surface 

 down to ten; the common sucker, to twenty; and the yellow 

 perch, to thirty. The bloater is found only in deep water, 

 below fifteen meters. 



Arranged according to their abundance as judged by the 

 catch per hour in the writer's gill nets, the fishes in Lake Michi- 

 gan rank in the following order: yellow perch, 2.538; pickerel, 

 .265; bloater, .107; rock bass, .053; common sucker, .053; 

 black bullhead, .036; pumpkinseed, .021; carp, .012. Only 



