98 
Abstract — Trawling was conducted 
in the Charleston, South Carolina, 
shipping channel between May and 
August during 2004—07 to evaluate 
loggerhead sea turtle (Caretta caretta ) 
catch rates and demographic distribu- 
tions. Two hundred and twenty indi- 
vidual loggerheads were captured in 
432 trawling events during eight sam- 
pling periods lasting 2-10 days each. 
Catch was analyzed by using a gener- 
alized linear model. Data were fitted 
to a negative binomial distribution 
with the log of standardized sampling 
effort (i.e., an hour of sampling with a 
net head rope length standardized to 
30.5 m) for each event treated as an 
offset term. Among 21 variables, fac- 
tors, and interactions, five terms were 
significant in the final model, which 
accounted for 45% of model deviance. 
Highly significant differences in catch 
were noted among sampling periods 
and sampling locations within the 
channel, with greatest catch furthest 
seaward consistent with historical 
observations. Loggerhead sea turtle 
catch rates in 2004-07 were greater 
than in 1991-92 when mandatory use 
of turtle excluder devices was begin- 
ning to be phased in. Concurrent with 
increased catch rates, loggerheads 
captured in 2004-07 were larger 
than in 1991-92. Eighty-five percent 
of loggerheads captured were <75.0 cm 
straight-line carapace length (nuchal 
notch to tip of carapace) and there was 
a 3.9:1 female-to-male bias, consistent 
with limited data for this location two 
decades earlier. Only juvenile logger- 
heads <75.0 cm possessed haplotypes 
other than CC-A01 or CC-A02 that 
dominate in the region. Six rare and 
one un-described haplotype were pre- 
dominantly found in June 2004. 
Manuscript submitted 3 March 2011. 
Manuscript accepted 1 September 2011. 
Fish. Bull. 110:98-109 (2012). 
The views and opinions expressed 
or implied in this article are those of the 
author (or authors) and do not necessarily 
reflect the position of the National Marine 
Fisheries Service, NOAA. 
Catch rates and demographics 
of loggerhead sea turtles ( Caretta caretta ) 
captured from the Charleston, South Carolina, 
shipping channel during the period 
of mandatory use of turtle excluder devices (TEDs) 
Michael D. Arencft 1 
Jeffrey A. Schwemter 1 
Albert L. Segars' 
Julia I. Byrd 1 
J. David Whitaker 1 
David W. Owens 2 
Gaelle Blanvillain 2 
Joseph M. Quattro 3 
Philip P. Maier 1 
Mark A. Roberts 3 
Email address for contact author: arendtm@dnr.sc.gov 
1 South Carolina Department of Natural Resources, Marine Resources Division 
217 Fort Johnson Road 
Charleston, South Carolina 29412 
2 College of Charleston 
Grice Marine Laboratory 
205 Fort Johnson Road 
Charleston, South Carolina 29412 
3 University of South Carolina, Department of Biological Sciences 
715 Sumter Street 
Columbia, South Carolina 29208 
Fisheries interactions are the great- 
est perceived threat to sea turtles 
(Wallace et al., 2010a), with specific 
fisheries differentially afflicting vari- 
ous life history stages across most 
developmental and foraging habi- 
tats (Wallace et ah, 2010b). Conse- 
quently, techniques to reduce sea 
turtle bycatch have been evaluated 
for multiple fisheries (Brewer et al., 
1998; Watson et al., 2005; Gilman 
et al., 2010). Prevalent among such 
measures is the turtle excluder device 
(TED) which enables sea turtles to 
escape and return to the surface to 
breathe while bottom trawling con- 
tinues. Because of the coastal nature 
of most trawl fisheries, Kemp’s ridley 
( Lepidochelys kempii) and loggerhead 
( Caretta caretta) sea turtles foraging 
on benthic prey (Shaver, 1991; Plotkin 
et al., 1993; Seney and Musick, 2007) 
have likely benefited more from TEDs 
than herbivorous green sea turtles 
(Chelonia mydas ) grazing in shallow, 
nearshore habitats (Seminoff et al., 
2002) or leatherback sea turtles ( Der - 
mochelys coriacea) pursuing gelatinous 
prey near the water surface and off- 
shore (Eckert et al., 1989) from where 
most coastal trawl fisheries operate. 
Before implementing TEDs, sea 
turtle mortality in coastal trawl fish- 
eries was estimated to exceed mor- 
tality from all other anthropogenic 
sources (NRC, 1990). Trawl-related 
mortality of loggerhead sea turtles 
remains a concern given that follow- 
ing an initial postpelagic settlement, 
juveniles predominantly forage in 
neritic habitats for approximately 19 
years until they reach maturity, after 
which neritic habitats are used exten- 
sively (Conant et al., 2009). Because 
most loggerhead strandings before 
TED implementation were those of 
large juveniles with a high conserva- 
tion value (Crouse et ah, 1987), re- 
ducing mortality of large juveniles 
was a high priority. In the southeast 
United States, TEDs were mandated 
for most trawl fisheries in federal 
waters in 1987 (Federal Register, 52 
FR 6179-6199); however, year-round 
use was not required for several more 
years and TED openings were not 
large enough to benefit large juve- 
niles and adults until 2003 (Federal 
