Variation in the Time of Run, Sex Proportions, Size and Egg Content of Adult Pink Salmon (Oncorhynchus gorbuscha) at McClinton Creek, Masset Inlet, B.C.

The spawning runs of pink salmon to McClinton creek, Masset inlet, B.C., in 1930, 1932, 1934, and 1936, differed little in time of appearance of the first migrant and disappearance of the last. The period occupied for the main portion of each run to reach the spawning beds depended chiefly upon rainfall and freshet conditions. Males occurred in greater numbers at the beginning of every run but a subsequent increased influx of females eventually brought about equality of the sexes in two seasons. In the third the males predominated slightly, and in the fourth the females. The average length and weight of males are consistently greater than those for females in the same year. Usually a significant increase in length occurred in both sexes from the commencement to the end of the run. In some cases a similar gain in weight was demonstrated but in others it was apparently masked by loss in weight consequent upon fasting during the spawning migration. The number of eggs per female in a given year increases with increase in length and weight.