between Early Marine Growth of Juvenile Bristol Bay Sockeye Salmon, Subsequent Marine Survival, and Ocean Conditions
Bristol Bay sockeye salmon (Oncorhynchus nerka) from the eastern Bering Sea were used to test the critical-size, critical-period hypothesis (Beamish and Mahnken 2001; Beamish et al. 2004). We examined a time series (42 years) of survival (brood year return per spawner from the Kvichak and Egegik riv...
| Main Authors: | , , , , , , |
|---|---|
| Other Authors: | |
| Format: | Text |
| Language: | English |
| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.552.4298 http://www.npafc.org/new/publications/Technical Report/TR6/page 46(Farley).pdf |
| Summary: | Bristol Bay sockeye salmon (Oncorhynchus nerka) from the eastern Bering Sea were used to test the critical-size, critical-period hypothesis (Beamish and Mahnken 2001; Beamish et al. 2004). We examined a time series (42 years) of survival (brood year return per spawner from the Kvichak and Egegik river systems in southwest Alaska) and early marine growth (mean circuli spacing for the first marine year) from preferred scales (Clutter and Whitesel 1956) collected from returning adult salmon to these river systems. Four major age classes of sockeye salmon return to Bristol Bay, including 1.2, 1.3, 2.2, and 2.3, where the numbers to the left and right of the decimal point indicate the number of years spent in freshwater lakes and the number of years in the ocean, respectively. The data were lagged to reflect growth during the first year at sea (1958–2000) for freshwater age 1.0 and 2.0 sockeye salmon. Early marine growth was compared with survival of adult sockeye salmon using regression analysis and was found not to be significantly related to survival of Bristol Bay sockeye salmon. We also compared early marine growth between river systems for each freshwater age class and between freshwater age classes. Average circuli spacing between Egegik and Kvichak age 1.0 and 2.0 salmon was relatively uniform as was average circuli spacing between age 1.0 and 2.0 fish. A lack of relationship between adult sockeye salmon survival and early marine growth as |
|---|