94 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



Table 5. — Age composition of lake herring taken in commercial pound nets, by quarters, 1949-52 



[Dominant age groups indicated by asterisk] 



' Average number of annull. 



belonging to age group III captured in 1949 be- 

 longs to the 1946 year class. 



AGE COMPOSITION 



The principal characteristics of the age com- 

 position of Green Bay lake herring taken in the 

 commercial fishery (tables 5 and 6, and fig. 2) are 

 the shift from older to younger fish during the 

 calendar year and a strong tendency for the same 

 age group to be dominant year after year during 

 the same season. 



In pound-net collections made during the first 

 quarter (January-March), age group IV was 



Table 6. — Age composition of lake herring taken in com- 

 mercial gill nets, in 1948. 1950, and 1951, and experi- 

 mental gill nets in 1952, by quarters 



[Dominant age groups Indicated by asterisic] 



100 

 80 

 60 

 40 

 20 



I 60 



I 20 



uj 80 



O 



< 



P 60 



z 



uj 



O 40 



X 



UJ 



°- 20 

 

 60 

 60 

 40 

 20 



APRIL - JUNE 



JULY - SEPTEMBER 



IV V 



AGE GROUP 



' Average number of annuli. 



Figure 2. — Age composition of lake herring taken in com- 

 mercial pound nets (solid line), and commercial and 

 experimental gill nets (broken line) in various quarters, 

 1948-52. 



