SALMON RUNS OF THE COLUMBIA RIVER IN 1938 



127 



Before adopting the policy of treating all of the data on the basis of time units of 

 1 week, the daily records were examined and it soon appeared that there was, espe- 

 cially in June and July 1938, a very definite weekly cycle of abundance as indicated 

 by the catch in Zones 1 and 2. The Sunday closed season, of course, resulted in 



1915 1920 1925 1930 1935 



Figure 4.— Trends of the total monthly deliveries to the Columbia River Packers Association, 1912-37. 



practically no catch on that day, but there was a distinct tendency for the catches to 

 be highest early in the week and to drop gradually toward the end of the week. The 

 natural interpretation was that during the Sunday closed period a body of fish entered 

 the river and on Monday (actually beginning Sunday evening) there were available 

 to the fishermen, in addition to those left at closing time on Saturday, all of the fish 

 that had entered the river and that were free of all commercial fishing during an 



