462 
Fishery Bulletin 109(4) 
Table 3 
Tag and recapture data for sandbar shark (Carcharhinus plumbeus ) over a period of several decades. Specimen IDs 1-10 revealed 
life spans exceeding 20 years and the remaining specimens had time at liberty (TAL) exceeding 10 years. Age at tagging was 
estimated from the Casey et al. (1985) growth function. Age at recapture was the sum of estimated age at capture and time at 
liberty. Italicized lengths were estimated. NR=not reported. U=unidentified. 
Specimen 
ID 
Fork length (cm) 
Estimated age (years) 
Sex 
Tagging 
Recapture 
Growth 
TAL (yr) 
Tagging 
Recapture 
1 
F 
183 
160 
-23 
2.6 
19 
21.4 
2 
F 
152 
170 
18 
7.6 
13 
20.5 
3 
M 
139 
140 
1 
9.0 
11 
20.1 
4 
F 
152 
145 
-7 
10.2 
13 
23.0 
5 
F 
156.6 
169 
12 
12.1 
14 
25.7 
6 
M 
154 
NR 
12.1 
14 
25.9 
7 
M 
127 
203 
76 
12.7 
9 
21.8 
8 
M 
80 
141 
61 
24.9 
3 
27.8 
9 
M 
106 
136 
30 
24.9 
6 
31.1 
10 
F 
87 
166 
79 
26.9 
4 
30.6 
11 
M 
137 
152 
15 
11.0 
11 
21.7 
12 
F 
73 
202 
129 
11.0 
2 
13.1 
13 
M 
82 
154 
72 
11.0 
3 
14.2 
14 
M 
90 
127 
37 
11.0 
4 
15.1 
15 
F 
131 
127 
-4 
11.1 
10 
20.6 
16 
U 
102 
131 
29 
11.1 
6 
16.7 
17 
F 
127 
162 
35 
11.5 
9 
20.4 
18 
U 
115 
178 
63 
11.5 
7 
18.9 
19 
M 
137 
148 
11 
11.7 
11 
22.4 
20 
F 
102 
202 
100 
12.1 
6 
17.7 
21 
M 
115 
156 
41 
12.8 
7 
20.2 
22 
F 
91 
140 
49 
13.2 
4 
17.4 
23 
M 
140 
155 
15 
13.4 
11 
24.6 
24 
F 
127 
169 
42 
13.5 
9 
22.4 
25 
F 
90 
152 
62 
13.6 
4 
17.7 
26 
F 
102 
152 
50 
14.5 
6 
20.1 
27 
F 
123 
165 
42 
15.6 
8 
24.0 
28 
F 
122 
160 
38 
16.8 
8 
25.0 
29 
F 
102 
167 
65 
17.5 
6 
23.1 
30 
U 
115 
183 
68 
18.0 
7 
25.4 
31 
F 
91 
168 
77 
18.4 
4 
22.6 
32 
U 
99-122 
146 
47-24 
27.8 
5-8 
33-36 
tope shark ( Galeorhinus galeus ) in Australia (Kalish 
and Johnston, 2001). 
There is evidence to support a similar conclusion in 
terms of reduced or ceased somatic growth of the verte- 
brae. Two of the sandbar sharks in this study could be 
older because once prebomb A 14 C levels were attained 
there was no limit to maximum age. In contrast, the 
age of specimen SB 47970 was well constrained by the 
upper and lower limits of the A u C reference chronolo- 
gies for an age of 25 ±2 years. The five years estimated 
from band pair counts between the measured values for 
SB 47970 is consistent with the validated early growth 
from SB 43 (10 years old). Therefore, the addition of 11 
years, as part of the age estimate that was not quanti- 
fied for late adult life, was chosen to shift the observed 
five-year early growth period to match the A 14 C refer- 
ence records. 
In general, bomb radiocarbon dating of sharks must 
be qualified with empirical evidence to support a tem- 
poral correlation with a regional A 14 C reference chronol- 
ogy. Complexities tied to ontogenetic changes in feeding 
were recently observed to varying degrees in bomb 
radiocarbon dating studies of other sharks. Bomb radio- 
carbon dating of tiger shark ( Galeocerdo cuvier ) not only 
validated age estimates up to 20 years, but also provid- 
ed information about carbon sources from the measured 
levels of A 14 C (Kneebone et al., 2008). The interesting 
finding with tiger shark in terms of 14 C uptake was in 
the differences and similarities of values between juve- 
niles and an adult shark. Measured A 14 C values from 
