FLUCTUATIONS IN THE SUPPLY OF HERRING 
37 
it has not even been possible to obtain samples of herring from them. In such cases 
depletion is the only logical verdict. 
Unfortunately the staff has been too small in the past to permit of adequate 
sampling throughout Alaska, so that in the southeastern district, previous to 1929, 
the only summer samples available are from a few of the areas for the years 1925 
and 1927. Comparisons of the ages of the herring taken in these three years in 
areas 14 and 17 are shown in Figures 22 and 23. (See Table 9.) The passage of 
dominant year classes is apparent, but not so striking as the falling off of the older 
age groups in the later years. 
Table 9. — Age frequencies for areas 14 and 17 
The relative lack of older age groups in 1929 might be due to either of two causes: 
(1) To a scarcity of older fish due to depletion, or (2) to an unusual abundance of 
younger fish. If the latter were true, then the population as a whole should be very 
numerous; so numerous that the ordinary number of older fish constitutes but a 
small portion of the stock. This hypothesis needs to be carefully examined. The 
average percentages of herring above 4 years of age in the two areas in 1925, 1927, 
and 1929 were 96.5, 72.7, and 25.5, respectively. In 1927 when the proportion of 
herring over 4 years of age was 72.7, the average size of catch in areas 14, 15, and 17 
was 140.3 barrels; in 1929 when the proportion over 4 years of age was 25.5, the aver- 
age catch in the two areas was 164.1 barrels, or an increase of 17 per cent. If the 
relative lack of older age groups was entirely caused by the abundance of the 4-year- 
old group, the catch might have been expected to have increased to an average of 
400 barrels or an increase of 185 per cent, assuming in each case the actual numbers 
72 7 
of herring over 4 years of age to have remained the same, as equals 
400 
140.3* 
