Drags were made along bottom contours at 

 depths of 4 to 20 fathoms. Efforts were made 

 to secure as complete depth coverage as pos- 

 sible on each cruise. In the study of the depth 

 distribution of fish the following depth ranges 

 are combined to the nearest 5-fathom point in 

 all depth analyses in this paper. 



For certain evaluations of distribution and 

 the catch and in the appendix tables, GreenBay 

 is arbitrarily divided here into northern and 

 southern portions. The dividing line is lat, 

 45°12'30" N., which touches the northern tip 

 of Chambers Island {fig. 1). 



Calculations of fishing results are based on 

 two methods: (1) catch rate, which is pounds 

 produced per l/2-hour effort for all drags in 

 a particular evaluation, and (2) average catch 

 for effective fishing effort, which is pounds 

 per half-hour of effort for only those drags in 



which the particular species being evaluated 

 was taken. Effective fishing effort has been 

 discussed by Hile (1962). 



I consider a catch to be commercially sig- 

 nificant when its ex-vessel value is $7.50 or 

 more per half hour. Under current conditions 

 a significant catch would amount to 500 pounds 

 of alewives per half hour, based on a value in 

 between pet food and meal plant fish prices. 

 Since the other four most abundant species 

 taken during this study are usually caught with 

 others, we consider the following half-hour 

 catch rates to be commercially significant: 

 smelt - 150 pounds, suckers - 200 pounds, 

 carp - 200 pounds, and yellow perch - 75 pounds. 



FISHING EFFORT 



From 1963 through 1965, portions of 11 

 cruises in Lake Michigan were devoted to 

 fishing explorations in Green Bay. The total 

 operating time in Green Bay was 36 days-- 

 an average of over 3 days per cruise. During 

 the study, 179 trawl drags (over 86 hours of 

 fishing) were completed (table 1). Because 

 exploratory fishing cruises are numbered con- 

 secutively regardless of the area of operation, 

 cruise numbers given in this paper are not 

 consecutive. 



Table 1. --Exploratory fishing effort in Green Bay by cruise, 1963-65 



