Mc. Healey et al., Precocial maturation of male sockeye salmon in the Fraser River, British Columbia, and its relationship to growth and year-class strength, CAN J FISH, 57(11), 2000, pp. 2248-2257
Citations number
37
Categorie Soggetti
Aquatic Sciences
Journal title
CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES
We analyzed historical data on the age structure and abundance of males in
22 populations of sockeye salmon (Oncorhynchus nerka) in the Fraser River,
British Columbia, to determine geographical and temporal patterns of precoc
ial maturation, its relationship with growth and maturation at other ages,
and the value of precocial males as indicators of year-class strength. Most
Fraser sockeye males spend two winters at sea before maturing at 3-5 years
of age. Precocial males return to spawn at 2, 3, or 4 years of age (ages 0
.1, 1.1, and 2.1) and comprised <1 to > 33% of male brood year returns amon
g populations. Precocity was lowest among populations that spawned far upst
ream and highest among populations spawning to the west of the main Fraser
River and was not correlated with migration distance. Precocial maturation
was related to growth during the second summer in the ocean to brood line a
nd to brood line abundance. The combination of brood line, abundance, and s
ize of precocial males accounted for more than 75% of the variation in tota
l returns in four populations, suggesting that these variables might be use
d to predict abundance 1 year in advance.