LIFE HISTORY OV LAKE HERRING OF LAKE HURON 



353 



year, shown near the bottom of Table 29, are rearranged in the lower part of 

 Table 30 to facilitate a comparative study of the significant figures. The tables 

 show that no individuals in their first year of life and only a few in their second 

 year arc taken in these commercial catches. The percentage of 2-year herring 

 present in the samples varied from 0.2 per cent in 1924 to 0.8 per cent in 1922. 

 Likewise, the old fish are poorly represented. The 8-year fish were taken only 

 in 1921 and 1924, in each year representing 0.4 per cent of the sample. No 

 7-year fish were taken in 1922 or in the Tobico and Nayanquing samples in 1924, 

 while in 1921, 1923, and in the Gravelly Point and Au Gres samples in 1924 they 

 constituted 1.8, 0,4, 0.7, and 0.8 per cent, respectively, of the total catch. The 

 6-year herring were slightly more abundant, constituting from 1.8 per cent (0.8 per 



Fig. 16.— Frequency polygons showing tor each sample ot herring taken in 1921, 1922, 1923, and 

 1924 the percentage of individuals occurring in each age group. The curves are based on the 



percentages shown in the lower right hal( ot Table 30. — , 1921 ; . , 1922; 



, 1923; — ... — , 1924 (Tobico and Nayanquing samples combined) 



cent in the Au Gres sample of 1924) to 9.9 per cent of the catch. The values for 

 these older age groups are consistently greater in the 1921 sample, because strictly 

 it is not representative, inasmuch as all the exceptionally large fish (a dozen or so) 

 seen in the fish house were taken. The figures for the other samples are accurate, 

 however. The paucity of old individuals in the samples strongly suggests a condi- 

 tion of overfishing or rather of heavy fishing among the herring. A positive state- 

 ment to that efTect can not be made at present with absolute certainty, inasmuch as 

 nothing is known about the normal age distribution of the herring schools of the past. 

 In 1921 the 4 and 5 year fish formed the bulk of the sample— 72.9 per cent of 

 the total. In the three succeeding years the 3 and 4 year fish predominated, repre- 

 senting 78.4 per cent of the total in 1922 and 79 per cent in 1923; in 1924 they 

 formed 84.8 per cent of the Tobico and Nayaupuing material, 82.9 per cent of the 



