392 



Fishery Bulletin 101(2) 



40 



30- 



(1) 



Loa,QSL=0.875 + 0.005(A8e) 

 r2 = 0.91,n.96 



-I 1 1 1 1 f— 



40- 



30 



20 



10- 



CAPE FEAR 

 Upper 



" Lo9|„Sl = 0.856»0.005(A9o) 

 r^ = 0.94,n=91 



CAPE FEAR 

 Lower 



log,QSL=0.829+0.005(Agel 

 r2 = 0.90,n = 96 



■l 1 r— 



-I 1 1 f- 



60 80 100 120 140 160 60 80 100 120 140 160 



Age (days) 



Figure 6 



Spot growth rate curves (solid lines) based on otolith daily ages for upper and lower areas 

 of the Pamlico Sound and Cape Fear, NC estuaries. Dotted lines represent 95 percent 

 confidence intervals. 



(logj^SL = 6 -t- mkage)) was appropriate. Instantaneous 

 daily growth rates (slopes of the regressions) were similar 

 (analysis of covariance, P>0.05) between upper and lower 

 areas in the Cape Fear and the lower Pamlico (Fig. 6). 

 Therefore, a combined age-SL regression for all spot in the 

 upper and lower Cape Fear estuary and the lower Pamlico 

 area was developed: logipSL = 0.861 + 0.0048(a^e), r2=0.90, 

 n=2S3. Analysis of covariance indicated that spot from 

 the upper Pamlico region exhibited significantly slower 

 (P>0.05) overall growth rates (Fig. 6) than fish from the 

 other three areas. 



Age-specific absolute and relative growth of spot was 

 predicted from the age-SL regression for the upper and 

 lower ("ape Fear and lower Pamlico combined and the up- 

 per Pamlico (Table 2). Predicted absolute growth rates in 

 the Cape Fear and lower Pamlico areas increased from 0.16 

 mm/d between 60 and 65 days of age to 0.43 mm/d between 

 ages 150 and 155 days of age, and the largest increase in 

 absolute growth occurred between ages 95 and 105 days of 



age (Table 2). Relative growth remained constant around 

 1.13-1.14 %/d SL over the whole age range examined 

 (Table 2). Although predicted sizes at ages were larger in 

 the upper Pamlico area than those of the other three areas, 

 the absolute growth rates were lower, increasing from 0.16 

 mm/d between ages 60 and 65 d to 0.39 mm/d between ages 

 150 and 155 d (Table 2). Absolute growth rates in this area 

 also exhibited the largest increases around 100-105 days. 

 Relative growth rates in the upper Pamlico were lower 

 than in the other areas and averaged 1.01 9t/d SL (Table 2). 

 The ages when absolute growth in all areas was greatest 

 (95-105 d) translated to SL ranges around 21-23 mm. This 

 SL range dominated the length frequencies in all areas 

 during the first two weeks of April (Figs. 4 and 5). Water 

 temperatures were steadily increasing in all areas prior to 

 mid-April (Fig. 2). 



(Jrowth was also compared by using weight-length rela- 

 tionships. These relationships for spot were highly signifi- 

 cant (analysis of covariance, P<0.0001) and took the usual 



