Sensitivity of potential recruitment to stock structure in the presence of temporally varying survival.
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http://hdl.handle.net/11250/100427Utgivelsesdato
1999Metadata
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In this paper we discuss the results-of a modelling study which quantifies differences
in the number of potential recruits produced from a range of age-structured
populations over a spawning season with temporally varying survival rates. We
include investigations into the effects that variation in female condition and egg
quality (as a function of female characteristics) may have on overall production. We
also quantify the effects on production of potential recruits via changes in the overall
duration of spawning seasons due to environmental influences. The population stock
structure (the proportion of females in different age classes) has the most effect on
overall potential recruitment. The effects of egg quality dramatically increases larger
fish's output of viable offspring whilst decreasing that of smaller fish. Fish condition
has a very large effect on potential recruitment, but the effects are felt by all age
classes equally. The present model outputs dealing with the interactions of temporally
varying survival vs. stock structure and condition suggest that the middle of the
spawning period consistently produces the most potential recruits but that the relative
production of recruits over the spawning season is heavily influenced by both
condition and stock structure.
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ICES CM documents1999/Y:02