Mortensen et al : Growth of Oncorhynchus gorbuscha in relation to marine water temperature, secondary production, and survival 



327 



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Figure 5 



Water temperature, biomass of zooplankton and harpacticoid copepod prey of juvenile 

 pink salmon from the epibenthos, upper 5 m, and 40 m of Auke Bay, Alaska. Owing to 

 differences in collection technique between years, the values depicted for littoral harpac- 

 ticoids are expressed as a proportion of the highest biomass within each year. Littoral 

 harpacticoids were not collected in 1986. Zooplankton data for the upper 5 m and 40 m 

 were taken from Coyle and Paul ( 1990). 



of juvenile pink salmon might be restrained by prey 

 abundance, the observed growth of each tagged fish 

 was compared to maximum expected growth at simi- 

 lar water temperatures. In all years, the residuals 

 between observed and expected growth (observed- 

 expected) had significant positive slopes (Fig. 7), 



indicating that a higher proportion of early emi- 

 grants (rearing in relatively cool water) were below 

 expected growth rates compared with fish at higher 

 water temperatures (later emigrants). If abundance 

 of prey is not growth-limiting, the growth rate of 

 juvenile pink salmon at 5°C water temperature in 



