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Fishery Bulletin 107(4) 
Gulf of Mexico and northwest Atlantic Ocean), not at 
finer spatial scales (Gold et al., 1993; Seyoum et al., 
2000). This apparent discrepancy, whereby subadults 
show limited movements but genetic makeup is rela- 
tively homogeneous within each ocean, can potentially 
be explained in three ways. First, dispersal of larvae 
may occur over long distances along the coast, although 
evidence indicates that red drum spawn in inlets and 
estuaries (Johnson and Funicelli, 1991; Barrios, 2004; 
Luczkovich et al., 2008) where larvae are likely locally 
retained (Chen et al., 1997). Second, despite low move- 
ments rates (km/day) by subadults, adult movements 
may be high enough that genetic variability is homog- 
enized at a basin-wide scale; this hypothesis remains 
untested because adult movement patterns have not 
been quantified. Third, in previous examinations of 
subadult red drum movement at relatively small tem- 
poral and spatial scales the full extent of subadult 
movements may have been missed. 
We quantified the large-scale movements of subadult 
and adult red drum (using 25 years of conventional tag- 
ging data) and small-scale movement of subadult red 
drum (using three years of ultrasonic telemetry data. 
The specific objective of this work was to examine the 
effects of age, season, and region on movement patterns 
of North Carolina red drum. Potential differences in 
red drum movements by age, region, or season have 
implications for various aspects of the management 
(e.g., stock structure, spatial or temporal fishery clo- 
sures, selectivity patterns) and ecology of the species 
(e.g., timing and spatial scale of gene flow and popula- 
tion connectivity). We used a variety of quantitative 
approaches to describe subadult and adult movement 
patterns, including ultrasonic telemetry, geographic 
mapping, and circular mapping. This study improves 
our understanding of the movement of red drum in 
estuarine and coastal waters of North Carolina and 
estuarine fish species more generally, and also pro- 
vides some analytical techniques that are more widely 
applicable. 
Materials and methods 
Conventional tagging 
Two sources of conventional tagging data were used. 
The first source was from a tagging study conducted 
by the North Carolina Division of Marine Fisheries 
(NCDMF) between 1983 and 2007 when red drum 
were captured opportunistically with pound nets, hook- 
and-lines, runaround gill nets, trammel nets, and by 
electrofishing. Volunteer recreational and commercial 
fishermen also participated in tagging red drum. The 
second data source was from a tagging study of sub- 
adult red drum during 2005-2007 conducted by North 
Carolina State University (NCSU) personnel within 
the lower Neuse River estuary (Bacheler, 2008). In 
both of these studies, only healthy fish were tagged 
and released. 
Most subadult fish were tagged with internal an- 
chor tags (Floy®, Seattle, WA; FM-84, FM-89SL, and 
FM-95W) and nylon dart tags (Floy® FT-1 and FT-2), 
whereas adults were primarily tagged with stainless 
steel dart tags containing a monofilament core (Floy® 
FH-69) or, more recently, containing a stainless steel 
core (Hallprint® SSD wire-through, Victor Harbor, Aus- 
tralia). All tags were labeled with a unique tag number 
and a “reward” message. All tag types were combined 
and treated equally in this study. The tag recovery 
location was either provided as latitude and longitude 
by fishermen or was estimated from the physical de- 
scription provided by fishermen. For fishery-dependent 
tag recoveries, it was assumed that fishing effort was 
homogeneous over space, the implications of which are 
elaborated upon in the Discussion section. 
We used a 6-mo age-length key developed by NCDMF 
to convert total length of fish at tagging to an estimated 
age based on a 1 January birthday. The age-length key 
was based on 17 years of North Carolina red drum 
ages that were estimated from otoliths, the annuli of 
which had been validated by Ross et al. (1995). A 6-mo 
age-length key (January- June and July-December) 
was used because of rapid summer growth rates that 
subadult red drum experience in North Carolina wa- 
ters (Ross et al., 1995). The key provided very good 
separation of length-groups for fish younger than age 4. 
Sexually mature red drum were grouped into a single 
age-bin (age 4 and older [4+]; Ross et al., 1995). Thus, 
we used four age-groups (ages 1, 2, 3, and 4+) for all 
analyses. Lengths of fish were grouped into the four age 
bins as follows: for January-June, age 1: 0-253 mm, 
age 2: 254-558 mm, age 3: 559-761 mm, and age 4+: 
greater than 761 mm; for July-December, age 1: 0-507 
mm, age 2: 508-710 mm, age 3: 711-812 mm, and age 
4+: greater than 812 mm. In previous aging studies of 
adult red drum in North Carolina, maximum age was 
determined to be 62 years (Ross et al., 1995), indicating 
that age-4+ red drum in our study potentially ranged 
from age 4 to greater than 60. 
Specific fishery regulations for red drum in North 
Carolina should not be a major source of bias in age- 
specific movements. The fishery regulation history for 
red drum is complex in North Carolina (see Bacheler et 
al. [2008a] for details), and currently only fish within a 
window limit (= a size limit with minimum and maxi- 
mum length requirements, i.e., 457-686 mm TL, cor- 
responding to ages 1-3) can be harvested legally. How- 
ever, all ages of red drum are encountered in various 
(popular and targeted) catch-and-release recreational 
fisheries, and there are no major temporal or spatial 
restrictions on these fishing efforts. 
To understand the generality of movement patterns of 
red drum in North Carolina waters, we first tested for 
differences in movement patterns among four regions 
(Fig. 1). These regions were the following: 1) eastern 
Pamlico Sound and the adjacent coastal waters (EPS; 
the outer banks from the Virginia state line to Cape 
Lookout), 2) western Pamlico Sound (WPS; waters near 
mainland areas of northern North Carolina), 3) Neuse 
