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Fishery Bulletin 1 10(3) 
nmi south (29°51'N) on eastern transects and out to 
60 nmi south (29°19'N) on western transects to cover 
the Chandeleur Islands. The longitudinal coverage 
extended from the Chandeleur Islands in the west 
(88°59'W) to Pensacola, FL, in the east (87°19 / W) (13 
surveys). Two observers wearing polarized sunglasses 
conducted the survey by scanning the water to iden- 
tify organisms from an average altitude of -213 m. 
When fish were spotted, the observer signaled to the 
pilot to circle the object to confirm species identifi- 
cation, record GPS location, and take photographs 
of the fish school. These aerial surveys lasted ap- 
proximately 8 hours and were conducted in two 4-hr 
flights with a fuel stop in between flights (Fig. 1C). 
To increase the sample size for growth determina- 
tion, we augmented our fishery-independent samples 
with a fishery-dependent collection of red drum greater 
than 660 mm TL at the 2009 Alabama Deep Sea Fish- 
ing Rodeo (ADSFR) on Dauphin Island, AL. Alabama 
state law allows 1 red drum >26 inches (660 mm) TL 
to be kept per day in state waters (within 3 miles from 
the coastline). Tournament anglers were entered into 
a random drawing if they turned in a red drum >26 
inches. Prizes were not based on weight or length and 
hence anglers had no incentive to “high grade” the fish 
and turned in the first large red drum they caught. 
This tournament provided an additional 176 samples. 
Fish landed at the ADSFR were caught from the nc- 
GOM, including adjacent bays and coastal waterways, 
bounded on the east at longitude 85°, south at latitude 
28°, and west at longitude 91°. 
Standard measurements were collected for all red 
drum sampled by fishery-independent (bottom long- 
line) or fishery-dependent (ADSFR) gears. Standard 
length (SL), fork length (FL), and TL for each fish were 
measured to the nearest millimeter. Total length was 
defined as natural total length without pinching the 
tail. Each fish was also weighed (g) and sex was de- 
termined. Gonads and any intraperitoneal fat were 
removed and weighed (g). Two-sample Kolmogorov- 
Smirnov (KS) tests were used to examine for differences 
in size distribution between fishery-independent and 
fishery-dependent sampled red drum. 
Fish condition 
Beginning in 2008, 3 indices were calculated to assess 
fish condition: gonadosomatic (GSI), intraperitoneal 
fat (IPF), and Fulton condition indices. Gonadosomatic 
and IPF indices are measures of condition where gonad 
weight (GSI) or fat content (IPF) is divided by total body 
weight then multiplied by 100 (Wilson and Nieland, 
1994; Craig et ah, 1995). The Fulton condition index 
was calculated by dividing weight of the fish by TL 3 
and multiplying by 100,000 (Ricker 1975). Differences in 
IPF between males and females were tested for using a 
nonparametric Mann-Whitney U test on pooled log(x-t-l) 
transformed data. Differences in sex ratio were tested 
for using a G-test (Zar, 1999) against an expected 1:1 
male-to-female ratio. 
Age determination 
Beginning in 2008, ages were determined for all red 
drum captured on the bottom longline survey (rc=227) 
and for fish collected at the ADSFR in July 2009 (n=176). 
Sagittal otoliths were removed and processed according 
to the methods described in the otolith manual of the 
Gulf States Marine Fisheries Commission (VanderKooy 
and Guidon-Tisdel, 2003). Each otolith was weighed to 
the nearest gram. Material from the left otolith was 
removed starting from the anterior side with a thin- 
section saw (Hillquist, Inc., Denver, CO) until the core 
was reached. The sectioned otolith was polished and 
mounted on a glass slide with Loctite 349™ (Henkel 
Corp., Diisseldorf, Germany) light-sensitive glue and left 
to set overnight under an ultraviolet light. The otolith 
was then sectioned to approximately 0.50 mm. Each oto- 
lith section was polished and covered with a thin coat of 
liquid cover slip to smooth out any remaining scratches. 
Opaque zones (annuli) were counted from the core to 
the margin in the medial direction. The right otolith 
was used when the left was not available or when there 
was a disagreement between otolith readers (Beckman 
et al., 1988). Each otolith was aged independently by 
two readers, and the estimated ages were compared. If 
the reader’s initial estimates did not agree, they jointly 
examined the otolith in question. If the resulting ages 
still disagreed, the otolith was read by a third reader. 
If the third reader did not agree with one of the two 
initial readers, the otolith was excluded from the sample 
set (Johnson et al., 2010). Average percent error (APE) 
was calculated by the methods outlined in Beamish and 
Fournier (1981). 
Von Bertalanffy growth curves were fitted to both 
males and females for the complete data set, the fish- 
ery-independent (longline) data set, and the fishery- 
dependent (ADSFR) data set by using the following 
equation: 
L t = L„[ l- e *ft-tol], (2) 
where L t - TL at time t\ 
L x = the asymptotic length; 
e = the base of natural logarithms; 
k - the von Bertalanffy growth coefficient, 
t = age; and 
t 0 = the theoretical age at which TL equals zero 
(von Bertalanffy, 1938). 
Differences in growth curves between males and females 
were tested for using a likelihood ratio test (Kimura, 
1980; Haddon, 2000). 
Results 
Distribution of red drum 
A total of 428 adult red drum were captured on bottom 
longline cruises at multiple locations from Mississippi 
