We tested the hypothesis that larger juvenile sockeye salmon
(Oncorhynchus nerka) in Bristol Bay, Alaska, have higher marine-stage survival rates than smaller juvenile salmon. We used scales from returning adults (33 years of data) and trawl samples of juveniles (n= 3572) collected along the eastern Bering Sea shelf during August through September 2000−02. The size of juvenile sockeye salmon mirrored
indices of their marine-stage survival rate (e.g., smaller fish had lower indices of marine-stage survival rate). However, there was no relationship between the size of
sockeye salmon after their first year at sea, as estimated from archived scales, and brood-year survival size was relatively uniform over the time series, possibly indicating size-selective mortality on smaller individuals
during their marine residence. Variation in size, relative abundance, and marine-stage survival rate of juvenile
sockeye salmon is likely related to ocean conditions affecting their early marine migratory pathways along the
eastern Bering Sea shelf
