SALMON AND SALMON FISHERIES OF SWIFTSURE BANK 
745 
In the odd years a considerable number of catches are made throughout July, 
but the peak of the season is reached during the pink run in the month of August. 
Fishing terminates rather abruptly thereafter, the bulk of the vessels moving to the 
inside waters. 
RELATION OF FISHING INTENSITY TO SEASONAL OCCURRENCE 
Both seasonal occurrence and fishing intensity determine the proportion of the 
annual catch made at different intervals in the season. In order to portray the seasonal 
distribution of the catch, 
, , , , , . ODD YEARS 
the percentage taken in 
each 7-day period was cal- 
culated, for vessels of 10-39 
net tons, for each year from 
1916-34. The years 1920 
and 1930 were omitted for 
reasons previously ex- 
plained. The average per- 
centages, by 7-day periods, 
were calculated for both 
odd and even years. 
These weekly percent- 
ages differ from the pre- 
viously calculated figures 
for fishing intensity in that 
they show the relative 
number of fish caught dur- 
ing uniform parts of the 
season, whereas the inten- 
sity figures represent the 
fishing effort during similar 
periods. 
Since it is also impor- 
tant to know the contribu- 
tion of the individual 
species, their proportionate 
representation in the week- 
ly catches of each year 
from 1916-34 were calcu- 
lated and the average week- Figure 19.— Seasonal distribution of the catch of Puget Sound purse seines and the pro- 
portional contribution of the various species. The striking difference of the impor- 
tance of the summer and fall fisheries in odd and even years is readily apparent. 
8 22 
SEPT. 
WEEK ENDING 
ly proportions for odd and 
even years determined. 
Corrections were made for closed periods in a manner similar to that described 
in the calculation of seasonal fishing intensity. The average proportion of the catch 
taken by weeks, and the average representation of the individual species are presented, 
for both odd and even years, in table 20 and in figure 19. 
