the weir; some females were measured for 

 length; average fecundity was determined; and 

 some females were tagged to determine the 

 distribution of the run on the spawning ground. 

 The number of females in each study section 

 was counted during daily surveys by foot. 



Number and Sex of Adults and 

 Time of Migration 



A total of 5,761 adult pink salmon were 

 counted at the Sashin Creek weir in 1966 

 (table 1), of which 3,026 (52.5 percent) were 

 females. The proportion of females in the 

 weir count from 1959 to 1965 had ranged 

 from 48.0 to 56.7 percent. 



Pink salmon normally gather in the estuary 

 of Sashin Creek by mid- August and move 

 into the stream in late August and early 

 September as they mature sexually and as 

 freshets occur. The streamflow is rarely 

 so low or high that their migration is blocked. 

 Larger escapements generally enter the 

 stream over a longer period than smaller 

 escapements. In 1966 the escapement ofadults 

 entered the stream in a shorter period of time 

 than the average for the last 10 escapements 

 of more than 1,000 fish (table 4). Faster 

 entry was true for both the 10 to 50 percent 

 and 10 to 90 percent segments of the escape- 

 ment. 



Distribution of Females on the 

 Spawning Grounds 



The distribution of female pink salmon 

 on the spawning grounds was estimated on 

 the basis of the daily count of all females 

 on the spawning grounds and on the distribu- 

 tion on the spawning grounds of females tagged 

 at the weir. Fifty females were tagged after 

 27 females had entered the stream; 50 were 

 tagged after 516 had entered, 50 after 1,955, 

 and 29 after 2,940. I assumed that all females 

 counted into the stream (3,026) spawned and 

 that 96 percent (2,905) spawned in the three 

 study sections. These assumptions seem justi- 

 fied because no predation of unspawned females 

 was seen; no dead unspawned females were 

 found; and 96 percent of the spawning ground 

 is within the three study sections. 



The distribution of females among the study 

 sections was determined in two ways-- (1 ) from 

 estimates of female-days in each section, 

 based on stream survey counts of all females, 

 and (2) from the distribution of taggedfemales. 

 In the first method, the number of females 

 spawning in each section was estimated by 

 dividing the total female-days (summed daily 

 counts of females) by the average "redd life" 

 (the average time a female spends on the 

 spawning ground) of the tagged females for 

 each section. The number of females counted 

 at the weir was then apportioned to each section 



Table 4 Dates of stream entry of the 10-, 50-, and 90-percent portions of escapements and 



elapsed days for pink salmon entering Sashin Creek for the last 10 escapements of more than 

 1,000 fish, 194-7-65, and the introduced even-year line, 1966 



Year of 

 escapement 



Adults in 

 escapement 



Date of entry of portions 

 of the escapement 



10 percent 



50 percent 



90 percent 



Elapsed days between 

 dates of entry 



10 and 50 

 percent 



10 and 90 

 percent 



Number 



1947 



1949 



1951 



1953 



1955 



1957 



1959 



1961 



1963 



1965 



Average. 



1966 



1,486 



4,902 



4,366 



1,164 



9,267 



2,834 



35,391 



28,759 



16,757 



14, 833 



5,761 



Sept. 7 

 Sept. 2 

 Aug. 28 

 Aug. 16 

 Aug. 29 

 Aug. 14 

 Aug. 13 

 Aug. 12 

 Aug. 13 

 Aug. 19 



Aug. 18 



Aug. 26 



Sept. 14 

 Sept. 12 

 Sept. 6 

 Aug. 29 

 Sept. 1 

 Aug. 22 

 Aug. 29 

 Aug . 14 

 Aug. 27 

 Aug. 26 



Aug. 23 



Aug. 31 



Sept. 22 



Sept. 19 



Sept. 17 



Sept. 7 



Sept. 11 

 Aug. 31 



Sept. 8 



Sept. 2 



Sept. 3 



Sept. 14 



Sept. 8 



Sept. 4 



7 

 10 



9 

 13 



3 



8 

 16 



2 

 14 



7 



15 

 17 

 20 

 23 

 14 

 17 

 26 

 19 

 21 

 26 



20 



