Garner and Patterson: Fishing effort, catch, and discard rates of charter boats in the Gulf of Mexico 
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i 
o 
5 
2 
O open 
0 closed 
15 
40 
to 
O 30 
5 
5 
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tn 25 
-O 
Figure 2 
Mean values of catch and discard variables — number of fishes caught, 
red snapper caught, and species caught; percentage of the catch that 
was red snapper; and number of discards (all fishes and red snapper 
only) — from observed charter boat trips in the northern Gulf of Mexico 
during open and closed red snapper seasons for red snapper (Lutjanus 
campechanus ) in 2012 and 2013. 
red snapper was 3.1 times greater (AN OVA, Ei ; 52=76.32, 
P<0.001) than during closed season trips. However, nei- 
ther the total number of discards nor the number of red 
snapper discards was significantly different between 
open- and closed-season trips (ANOVA, P>0.266). 
The species composition of the catch from charter 
boat trips was significantly different between red snap- 
per open and closed seasons (PERMANOVA, pseudo- 
Fi ; 53=21.46, P<0.001; Table 1). Red snapper accounted 
for the highest percentage of the catch during open- 
season trips (76.6%) and the second highest percent- 
age during closed-season trips (23.3%). Apart from red 
snapper, only vermilion snapper (11.9%) contributed 
more than 10% of the catch on open-season trips; this 
species was sometimes targeted after the daily bag 
limit of red snapper was reached. The catch of vermil- 
ion snapper increased nearly 3-fold for closed-season 
trips in contrast to open-season trips, but even larger 
increases between seasons were seen for other species 
(Table 1). In fact, reef fishes (e.g., vermilion snapper, 
red porgy, and tomtate [Haemulon aurolineatum]) that 
were smaller (<350 mm TL) in size and lower in value 
than red snapper composed the majority (54.9%) of 
the total catch for trips taken during the red snapper 
closed season. Pelagic species, primarily little tunny 
(Euthynnus alletteratus ] and king mackerel ( Scomb - 
eromorus cavalla), were caught infrequently (<1% of 
the total catch) during normal bottom fishing activities 
during both open and closed seasons. 
The species composition of discards from charter 
boat trips was significantly different between open and 
closed red snapper seasons (PERMANOVA, pseudo- 
Fi;5i=6.33, P<0.001; Table 1). However, red snapper 
dominated discards from trips that occurred during 
both open (89.8%) and closed (63.3%) seasons despite 
lower catch rates in closed seasons (Table 1). Fisher- 
men preference had a greater effect on red snapper dis- 
cards during open seasons than did either minimum 
length limits or daily bag limits. Of the 583 red snap- 
per discards recorded by observers during trips that 
occurred during open seasons for red snapper, 492 dis- 
cards (84.4%) were the result of fishermen discarding 
live, legal-size (>406 mm TL) fish so that they could 
target larger fish for retention. Of the remaining dis- 
cards of red snapper observed during open seasons, 
13.4% were below the minimum length limit and 2.1% 
were discarded because fishermen already had reached 
their daily bag limit (2 fish per person per day). Mean 
TLs of red snapper were significantly different in 
comparisons among landed catch of red snapper re- 
tained during open seasons (633 mm [standard error 
(SE) 4.0)]), open-season discards (475 mm [SE 3.4]), 
and closed-season discards (443 mm [SE 7.0]; ANOVA, 
^2;l,439 =511.8, P<0.001; Fig. 3A), and mean values for 
all 3 groups were also significantly different in pair- 
wise comparisons (Tukey’s, P<0.001). 
Discarding of other reef fishes was almost exclu- 
sively driven by seasonal closures and minimum length 
limits. For example, all gag ( Mycteroperca microlepis) 
observed during this study were caught during closed 
seasons and were, therefore, discarded. No species, 
other than red snapper, were discarded as a result 
