Genetic Effect on the Dynamics of a Model of Pink ( Oncorhynchus gorbuscha ) and Chum ( O . keta ) Salmon
Different stock dynamics result from genetic and nongenetic mechanisms of determination of maturation age of chum salmon (Oncorhynchus keta) in a model of interacting pink (O. gorbuscha) and chum salmon stocks. When the model is disturbed from equilibrium by low survival in one pink salmon line, the...
| Published in: | Canadian Journal of Fisheries and Aquatic Sciences |
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| Main Author: | |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Canadian Science Publishing
1984
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| Subjects: | |
| Online Access: | http://dx.doi.org/10.1139/f84-178 http://www.nrcresearchpress.com/doi/pdf/10.1139/f84-178 |
| Summary: | Different stock dynamics result from genetic and nongenetic mechanisms of determination of maturation age of chum salmon (Oncorhynchus keta) in a model of interacting pink (O. gorbuscha) and chum salmon stocks. When the model is disturbed from equilibrium by low survival in one pink salmon line, the genetic mechanism (high heritability of maturation age) leads to biennial cycles of numbers of even-aged chums and of numbers of pinks, similar to observed cycles. The nongenetic mechanism (zero heritability of maturation age) results in a new equlibrium at which neither stock cycles. When one pink salmon line is completely removed the genetic mechanism leads to biennial cycles of abundance of even-aged chums; the nongenetic mechanism does not lead to such cycles. These effects persist at intermediate values of heritability of maturation age and in spite of stochastic variability. The model is an adaptation of the Ricker curve to two interacting stocks, the recruitment for each depending on the density of both. |
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