24 
Fishery Bulletin 109(1) 
est between readings 1 and 2 at 12.2%. The mean CV 
across all three readings was 12.1%. Low aging preci- 
sion was mostly due to overall poor clarity of otoliths 
and poorly defined bands. In addition, interpretation of 
growth bands close to the core was often particularly 
difficult, leading to high CVs, especially for younger 
fish. Bands towards otolith margins were also often 
difficult to distinguish. 
Bomb radiocarbon analysis resulted in negative A 14 C 
values ranging from -42.6%e to -67.8%e for fish esti- 
mated to have hatched before the mid-1960s, followed 
by rapid accumulation of A u C over the period of at- 
mospheric radiocarbon increase, to a peak of 93.4%c 
in 1974 and a subsequent decline of A 14 C levels in 
recent years (Table 1). The red bream h 14 C chronol- 
ogy followed a similar pattern to that of the reference 
chronology for haddock from Newfoundland but was 
shifted by about five years to later years (Fig. 4). The 
year of initial radiocarbon increase was 1963, which 
is about five years later than that for haddock. Simi- 
larly, the mean year of radiocarbon increase for red 
bream was 1968, which is six years later than that for 
haddock (Table 2). Overall, bomb radiocarbon results 
supported the interpretation of growth increments 
as annual growth rings. In addition, a strong linear 
relationship was detected between otolith weight and 
age (r 2 = 0.845; n=130), which further supports otolith 
interpretation. 
The von Bertalanffy growth curve fitted to males 
differed slightly from that fitted to females, and likeli- 
hood ratio tests indicated that growth functions were 
significantly different (_^ 2 =19.56, df=3, PcO.OOl; Fig. 
5A), even though individual growth parameters were 
not. Sex-specific VBGFs were: L t =573.5(l - e -0 -°- 079(<- 
(-6.il))) f or ma i eS) an d L t =597.8(l - e“ 0 080,t “ (_6 - 51)) ) for 
females. The combined VBGF for western North At- 
lantic red bream was: L t =583.1(l - e - _0 094u_(_3 - 69)) ). 
The growth coefficient was almost identical between 
males (/e = 0.079/yr, standard deviation 
[SD] = 0.014) and females (/e = 0.080/yr, 
SD = 0.017), but was higher for the com- 
bined sexes (k = 0.094/yr, SD = 0.013). In 
addition, females attained larger maxi- 
mum theoretical lengths than did males 
(females: = 597.8 mm, SD = 10.310; 
males: L oo =573.5 mm, SD = 7.551). All 
three growth curves are depicted in 
Figure 5A and show that red bream 
growth is rapid in the first years of 
life, then slows down until asymptotic 
length is reached at about 580 mm FL 
or age 35 (Fig. 5A). The addition of the 
22 specimens from the Azores (mean 
ages ranged from 1.5 to 10.5 years) 
did not have an appreciable effect on 
VBGF parameters; it merely increased 
k slightly to 0.100/yr. 
The age-frequency distribution 
based on reading 3 was multimodal 
for both sexes. Most males caught on 
the Charleston Bump fell into the age 
groups between 11 and 20 years and 
36 and 50 years and another slight 
peak occurred in the highest age group, 
66-70 years. The females were most 
abundant in the age groups from 11 to 
30 years and showed another slight in- 
crease in abundance from 41 to 50 years 
(Fig. 5B). 
Mortality estimates were calculated 
for the combined sexes by using the 
maximum age estimate from reading 
3 and von Bertalanffy growth param- 
eters for the combined-sex growth curve. 
Total mortality ( Z ) based on Hoenig’s 
equation was calculated as Z=0.06/yr 
by using 69 years, the maximum age 
estimate from growth band count, as 
t max . With IGOR+ program, we also es- 
PE 
Figure 2 
Transverse sections of sagittal otoliths under transmitted light show- 
ing (A) a male red bream ( Beryx decadactylus ) (fork length = 567 mm) 
estimated to be 61 years old; C = core, SC = sulcus acousticus, DM=dorsal 
margin, PE=proximal edge, DE = distal edge; (B) a female specimen (fork 
length = 502 mm) estimated to be 12 years old. Each dot represents a 
growth band (scale bar=l mm). 
