Relation between size‐at‐maturity and survival of progeny in chum salmon, Oncorhynchus keta (Walbaum)

Data on age‐ and size‐at‐maturity, growth, and abundance of chum salmon were collected from 1959 to 1977 at Olsen Creek in Prince William Sound, Alaska. Age composition of spawners (3 to 6‐year‐olds) varied from year to year: 4‐year‐old fish were the dominant age group in most (16 out of 19) years and 6‐year‐old fish usually represented less than 1 % of the returns. Mean size of older spawners was significantly larger than that of younger spawners. Size‐at‐maturity was similar among fish from different broods maturing at different ages in the same year. Size‐at‐maturity and survival of progeny were significantly related. The larger the mean size of spawners, the higher the survival rate to adulthood of their progeny. Possible reasons for this relationship are discussed.