352 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



were in the same interval (81-90 feet). The strongest indication of two concentration 

 zones of illegal fish is found in the scanty September data. Young whitefish were much 

 scarcer in the shallower water of the Saginaw Bay area than at corresponding depths 

 on the Alpena-Ossineke grounds. 



HARBOR BEACH GROUNDS 



The observations of 55 lifts of deep trap nets off Harbor Beach (no pound nets 

 were observed here) were all made in the latter part of the 1932 season (table 26), 

 when on the basis of the preceding data the whitefish would be expected to be con- 

 centrated in the deeper water. Actually here is where the deep trap nets were found 

 in operation. Fifty of the lifts were made from depths greater than 90 feet. Con- 

 sequently, no detailed description of the vertical distribution of whitefish at all depths 

 in this area is possible. The maximum concentration of both legal and illegal whitefish 

 occurred in the 101-110 foot interval in all three months. In the season's average the 

 number of legal fish per lift was greater at 91-100 feet than in waters deeper than 110 

 feet, but the reverse relationship was found in the data for illegal whitefish. The single 

 shallow-water lift (41-60 feet) contained no whitefish. The legal whitefish were more 

 abundant than the illegal fish at all depths. 



Table 26. — Number of legal and illegal whitefish per lift of deep trap nets off Harbor Beach, 1932 

 [Number of lifts in parentheses. .Asterisks indicate concentrations] 



BATHYMETRIC DISTRIBUTION OF WHITEFISH IN LAKE MICHIGAN 



GREEN BAY AREA (MARINETTE, ESCANABA, AND FAIRPORT) 



The 30 lifts of pound nets and deep trap nets observed in the Green Bay area do 

 not offer adequate information on the bathymetric distribution of the whitefish at any 

 one time or on the seasonal movements of whitefish. The data of table 27, however, 

 indicate rather clearly that legal whitefish in this region were in deeper water in Sep- 

 tember (61-80 feet) than in May (60 feet and less). Illegal whitefish were relatively 

 numerous in May at depths less than 61 feet, and were present in large numbers also in 

 the two lifts from the 81-90 foot interval. Few illegal whitefish were taken at any 

 depth in September. 



