Newman and Dunk: Age validation, growth, mortality, and additional population parameters of Pristlpomoides multidens 123 



class 5 and relatively strong age classes 6, 8, and 10, but 

 abundance per age class declined rapidly to age 20, after 

 which few fish were found to be older (Fig. 9). The 1996 

 and 1997 samples were somewhat similar. In 1996 rela- 

 tively strong year classes were present from age 5 through 

 to age 11, and abundance per age class declined rapidly 

 to age 26 (Fig. 9). One year later, the 1997 sample had 

 relatively strong year classes present from age 6 through 

 to age 12 (Fig. 9), providing further evidence of the annual 

 formation of growth increments. 



The 1998 sample had relatively strong 6, 7, and 8 age 

 classes, and abundance per age class declined rapidly to 

 age 24 (Fig. 9). The 1999 sample was similar to the 1998 

 sample with relatively strong 6, 7, and 8 age classes, and 

 abundance per age class declined rapidly to age 20 ( Fig. 9 ). 

 Age classes 9 through 12 were somewhat eroded in the 

 1998 and 1999 samples in comparison to the 1996 and 

 1997 samples. In all years, abundance per age class 

 declined rapidly to age 20, and fish older than 20 years 

 were not well represented in the catch over the five years 

 of catch sampling. In most years there was a strong mode 

 of age-6 individuals present and this mode may reflect 

 the age at full recruitment to the sampling gear (fish 

 traps). 



Pristipomoides multidens less than age 6 were in gen- 

 eral not fully recruited to the sampled population and 

 were therefore excluded from the mortality estimates 

 derived from catch-at-age data. The year-specific total an- 

 nual rate of mortality, Z, of P. multidens in the NDSF, was 

 0.65 for 1995-96 (fish aged 6-21 years), 0.87 for 1996-97 

 (fish aged 6-21 years), and 0.71 for 1997-98 (fish aged 

 6-21 years), representing an annual percentage removal 

 of approximately 38%, 49%, and 41%, respectively, for each 



year (Table 4). In addition, exploitation rates were 0.79, 

 0.84, and 0.80, respectively. 



The optimum fishing mortality rate, F^^,, for P. multidens 

 was estimated to be 0.052-0.069, and the limit reference 

 point, F,,„,„, was estimated to be 0.069-0.092 (see Table 4). 

 These results indicate that only approximately 6% of the 



