162 
Fishery Bulletin 113(2) 
Length (mm TL) 
Age (Years) 
Figure 3 
Frequency histograms of (A) size (total length [TL] in millimeters) and (B) age (years) of red snapper ( Lutjanus 
campechanus ) discarded during closed seasons (closed discarded) and red snapper discarded or retained during 
open seasons (open discarded) and (open retained) during observed charter boat trips in the northern Gulf of 
Mexico in 2012 and 2013. n=the number of observations in each category (e.g., closed discarded). 
of reaching the daily bag limit, except one, legal-size, 
greater amberjack ( Seriola dumerili) that was discard- 
ed in 2012. In that case, 2 legal-size fish were caught 
simultaneously but only 1 fish was needed to fill the 
daily bag limit. Approximately half of the gray trig- 
gerfish (54.3%) and greater amberjack (56.8%) discards 
were the consequence of closed seasons for those spe- 
cies, and the remaining fish were discarded because 
of minimum length limits. No gag, greater amberjack, 
or gray triggerfish above their minimum length limit 
(559 mm TL, 762 mm FL, and 356 mm FL, respective- 
ly) were discarded when their respective recreational 
seasons were open and the daily bag limit was not yet 
filled. 
Among the catch, red snapper ages ranged from 1 
to 12 years, and average percent error between otolith 
readers was 1.31%. Mean age was significantly differ- 
ent in comparisons of red snapper retained as landed 
catch during open seasons (7 years), open season dis- 
cards (3 years), and closed season discards (2 years; 
ANOVA, F2;802=139.30, P<0.001; Fig. 3B). Red snap- 
per TL was affected significantly by hook front length 
(ANOVA, F 2 ;i, 419=160.10, PcO.001), but TL was not sig- 
nificantly different between medium and large hooks 
(Tukey’s, P=0.360), with mean red snapper TLs of 466 
mm (SE 5.7) for small hooks, 565 mm (SE 5.1) for me- 
dium hooks, and 575 mm (SE 5.0) for large hooks (Fig. 
4A). Similar to trends observed for red snapper, mean 
FL of all fishes caught on charter boat trips with ob- 
servers was significantly different for small, medium, 
and large hooks (ANOVA, F2;2, 674=894.20, P<0.001; 
Fig. 4B). Values of mean FL ranged from 355 mm (SE 
2.8) for small hooks to 574 mm ( SE 7.2) for large 
hooks and were significantly different for all pairs of 
hook sizes (Tukey’s, P<0.001). 
Discussion 
This study demonstrates the pervasive problem of dis- 
cards in the reef fish fishery in the northern GOM, 
particularly for red snapper. During open seasons, cap- 
tains of charter boats almost exclusively targeted fish 
at shallow artificial reefs (depths <40 m) where red 
snapper are highly abundant. During closed seasons, 
captains fished more frequently on natural reefs that, 
by comparison, had higher species diversity and lower 
red snapper abundances than those at the artificial 
reefs during open seasons, (Dance et al., 2011; Patter- 
son et al., 2014). 
Red snapper are ubiquitous at reef sites across the 
northern GOM and their aggressiveness toward fished 
