Early marine growth in relation to marine-stage survival rates for Alaska sockeye salmon (Oncorhynchus nerka)

• Main Authors: Farley, Edward V., Murphy, James M., Adkison, Milo D., Eisner, Lisa B., Helle, John H., Moss, Jamal H., Nielsen, Jennifer
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2007
• Subjects: Biology; Ecology; Fisheries; Bering Sea; Sockeye; Alaska
• Online Access: http://aquaticcommons.org/8937/; http://fishbull.noaa.gov/1051/farley.pdf; http://aquaticcommons.org/8937/1/farley_Fish_Bull_2007.pdf

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.