PACIFIC HERRING 
315 
5. In Cook Inlet the abundance, as shown by the comparative rates of change of 
the catch and of the purse-seine fleet, has fallen steadily since 1925. 
6. In Shuyak Strait the catch commenced to decline in 1926 and reached the 
vanishing point by 1928. 
EVIDENCE OF DEPLETION 
The results of the statistical analyses, the study of the composition of the catch, 
and other information give evidence that, in some instances, points to depletion. 
One evidence of depletion, the value of which is strengthened by the results of 
the study of the independence of areas, is the lack of continuity of the fishery in any 
one locality. The occasional appearance of dominant year classes may serve to 
explain fluctuations in abundance but hardly explains the scarcity of herring over 
long periods of years in localities where they formerly were abundant. This condition 
exists in Ivootznahoo Inlet (Moser, 1899), Yakutat (Moser, 1902; Alexander, 1912), 
and Yes Bay (Bower and Fassett, 1913). That this discontinuity can scarcely be 
due to migration is shown by the results of the studies on the independence of areas. 
Depletion would seem to be the logical cause for these declines in abundance. 
In the summer fishery of southeastern Alaska the abundance, as shown by the 
rates of change of the catch and the number of seine boats, decreased sharply in 
1927, but recovered somewhat in 1928. However, in 1928 a considerable portion of 
the pack came from areas 1, 9, 12, and 13 (fig. 8), distant areas scarcely touched by 
the summer fishery of previous years, so that the decline in abundance shown in 1927 
may have actually continued in 1928, although obscured by the exploitation of these 
more distant areas. Should this decline continue it must be considered as evidence 
of depletion. 
Another possible evidence of depletion in southeastern Alaska is the failure of 
the amount pickled, consisting of larger fish (fig. 46), to rise in conjunction with the 
tremendous increase in the total catch. However, there are so many factors involved, 
economic and otherwise, as to make any conclusions speculative, for in this district 
the pickling of herring has long been merely an adjunct to the oil and fish-meal 
industry. The increase in the size of the boats and the spread of the fishery to more 
distant areas would have much influence on the condition of the fish as received at 
the plant, perhaps preventing an increase in the amount pickled. 
In Prince William Sound the abundance has declined since 1922 with minor 
fluctuations. This decline has been especially sharp in the pickled portion of the 
catch, consisting of the larger fish. In this case the decrease in the amount pickled 
represents a real decrease in the abundance of older fish, as in this area the pickling 
of herring has always been the major object of the fishery. Although there are minor 
fluctuations that may be caused by factors which we can not estimate, such as the 
varying accessibility of the schools, yet the sharp downward trend over a 6-year 
period gives evidence of depletion. 
In Cook Inlet the great decrease in the catch per fathom of gill net since 1924 
indicates a decrease in abundance of at least the larger fish. The analysis of the purse- 
seine fleet shows that during this period both the gill-net and purse-seine catch were 
decreasing. The age analyses show that there were many year classes present so 
that the decline in abundance can not be construed as a mere temporary decline due 
to the passage of dominant year classes. Hence, depletion is believed to have 
occurred. 
