620 
Fishery Bulletin 99(4) 
100 200 300 400 500 600 700 800 900 1000 1100 
TL (mm) 
Figure 3 
Distribution of total length (TL) of red snapper sampled for age and growth 
estimation. 
ficial reef deployment (labeled 1986 in Fig. 1). Each fish 
was measured to TL and FL, tagged with a yellow Floy® 
(Seattle, WA) internal anchor tag, and released. Individu- 
als were recaptured on subsequent tagging trips or were 
recovered by recreational and commercial fishermen. Red 
snapper recaptured on tagging trips were measured to TL 
and FL and recovered fish were measured when fishermen 
retained carcasses of tagged fish. 
To corroborate red snapper age estimates, VBGF para- 
meters estimated from otolith-aged fish were incorporated 
into Fabens’ (1965) length increment model to predict TL 
at recapture of tagged fish (Labelle et al., 1993; Thompson 
et al., 1999). Solving for TL at recapture, Fabens’ model is 
computed as 
TLr t = 77, + (L„ - *,-) ( 1 - e~ kAt .), ( 1 ) 
where TLr, = predicted TL at recapture of individual i; 
TL t = TL at release of individual i; 
L oo = TL asymptote from VBGF estimated from 
otolith-aged fish; 
K = growth coefficient from VBGF estimated 
from otolith-aged fish; and 
t { = time at liberty of individual i. 
Predicted TL at recapture from Fabens’ method was plot- 
ted against observed TL at recapture to compare growth 
model predictions to observed values. 
Growth of tagged red snapper was estimated by regress- 
ing their change in TL on days at liberty (SAS Institute, 
Inc., 1996). A linear regression also was computed on TL- 
at-age data over the size range of recaptured individuals 
from the tagging study (SAS Institute, Inc., 1996). Slopes 
of resultant regressions were compared to assess if esti- 
mated growth rates were different between tagged and 
otolith aged fish. 
Results 
Age and growth 
Sagittae were collected from 1755 red snapper, including 
360 fish shorter than the minimum size limit (380 mm 
TL) caught on tagging cruises, 289 fish from tournaments, 
and 1106 fish randomly sampled from recreational catches 
(Fig. 3). Sex was not determined for 279 fish, of which 
61 individuals were immature. Mean TL (±SE) was 518.3 
(±5.04) mm for males and 529.5 (±5.96) mm for females. 
Total length of immature individuals ranged from 208 to 
309 mm. 
Of the 1755 otoliths sectioned for age determination, 
reader 1 and reader 2 agreed on the number of opaque 
zones for 1610 (91.7%) fish after the first reading; opaque 
zones in 23 otoliths were deemed not interpretable owing 
to sample preparation. Count disagreement between read- 
ers was the following: one opaque zone for 123 fish, two 
zones for 18 fish, and three zones for four fish. Otoliths 
were read a second time if reader counts were not in agree- 
ment and second otoliths were sectioned and read of the 
23 fish for which otoliths were rejected after the first read- 
ing. After the second reading, agreement was reached for 
1676 (95.6%) otoliths, including all 23 otoliths that were 
second sections. Disagreement between readers after the 
second reading was as follows: one opaque zone for 71 fish, 
two zones for 7 fish, and three zones for one fish; fish for 
