The relation between early marine growth of pink salmon, Oncorhynchus gorbuscha, and marine water temperature, secondary production, and survival to adulthood
Mortensen, D.; Wertheimer, A.; Taylor, C.M.; Landingham, J. (2000). The relation between early marine growth of pink salmon, Oncorhynchus gorbuscha, and marine water temperature, secondary production, and survival to adulthood. Fish. Bull. 98(2): 319-335
In: Fishery Bulletin. US Government Printing Office: Washington, D.C.. ISSN 0090-0656; e-ISSN 1937-4518, meer
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| Auteurs | | Top |
- Mortensen, D.
- Wertheimer, A.
- Taylor, C.M.
- Landingham, J.
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| Abstract |
Juvenile pink salmon, Oncorhynchus gorbuscha, from four consecutive brood years were tagged as they emigrated to the estuarine waters of Auke Bay, and information was obtained on the relationships between early marine growth, environmental conditions, and survival to adulthood. Juveniles that emigrated from Auke Creek later in the spring spent significantly less time in the estuary. Individual growth rates of tagged fish recovered in Auke Bay ranged from 3.1% to 7.1% per day. In all study years, juvenile pink salmon grew more slowly in early April than in late April and early May. Water temperature and growth were significantly correlated in all years, but growth did not consistently correlate with the biomass of epibenthic prey or zooplankton available to the fish. Comparisons of expected and observed growth rates suggested that low prey availability, as well as low temperatures, may have limited growth for early spring emigrants. Although early emigrants encountered poorer growth conditions, survivors were larger at a given date than later emigrants, their larger size possibly protecting them from size-selective predation. Early marine growth was significantly related to intra-annual cohort survival to adults (r²=0.65, P<0.05). Larger fish consistently survived better than their smaller cohorts for all years. Although early marine growth was an important determinate of survival within a cohort of pink salmon, other factors, such as predator abundance, contributed to the larger interannual variability observed. |
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