Figure 



Males 



Females 



370 380 390 400 410 420 430 

 ASYMPTOTIC LENGTH L„ IN MM 



Calculated value of co and rectanfiles showing two 

 standard errors about each estimate of the 

 theoretical growth oarameters L"' and K. 



Mortality and survival 



Survival was calculated by using a time-specific method. Because 

 of large apparent variability in estimated abundance of individuals of 

 specific year-classes, most likely due to changes in survey 

 methodologies and sampling errors, the cohort-specific methods of 

 estimating survival were considered less reliable (NUSCo 1983) . 

 Time-specific methods have advantages in that the age determinations of 

 older fish do not have to be known with certainty, although the 

 representativeness of the youngest age used in very important (Ricker 

 1975) . Since immature winter flounder (mostly ages 1 and 2) were found 

 both inside and outside the river during the survey period, their 

 relative abundance in the population age structure was not known with 

 certainty. Therefore, only ages 3 and older were used in the 

 calculations. The mean annual survival estimates for the 7-year period 

 was 0.565 (Table 11). This figure was somewhat larger than the 

 estimates reported in NUSCo (1983), which used age 2 fish in the 

 calculations and were not restricted to fish taken only during the 



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