458 
A comparison of size and age of red snapper 
( Lutjanus campechanus) with the age of artificial 
reefs in the northern Gulf of Mexico 
Tara S. Syc 
Stephen T. Szedlmayer (contact author) 
Email address for contact author: szedlst@auburn.edu 
Department of Fisheries and Allied Aquacultures 
Auburn University 
8300 State Highway 104 
Fairhope, Alabama 36532 
Abstract — Despite extensive study, 
it still is not clear whether artificial 
reefs produce new fish biomass or 
whether they only attract various spe- 
cies and make them more vulnerable 
to fishing mortality. To further evalu- 
ate this question, the size and age of 
red snapper (Lutjanus campechanus) 
were sampled from April to November 
2010 at artificial reefs south of Mobile 
Bay off the coast of Alabama and com- 
pared with the age of the artificial 
reef at the site of capture. Red snap- 
per were collected with hook and line 
and a fish trap and visually counted 
during scuba-diver surveys. In the 
laboratory, all captured red snapper 
were weighed and measured, and 
the otoliths were removed for aging. 
The mean age of red snapper differed 
significantly across reefs of different 
ages, with older reefs having older 
fish. The mean age of red snapper at 
a particular reef was not related to 
reef depth or distance to other reefs. 
The positive correlation between the 
mean age of red snapper and the age 
of the reef where they were found sup- 
ports the contention that artificial 
reefs in the northern Gulf of Mexico 
enhance production of red snapper. 
The presence of fish older than the 
reef indicates that red snapper are 
also attracted to artificial reefs. 
Manuscript submitted 25 July 2011. 
Manuscript accepted 23 August 2012. 
Fish. Bull. 110:458-469 (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. 
Red snapper ( Lutjanus campechanus , 
Poey, 1860) has been historically 
targeted by both sport and commer- 
cial fishermen in the Gulf of Mexico 
(Camber, 1955). Because of intense 
fishing pressure, the estimated popu- 
lation abundance in this region has 
decreased and the stock is considered 
overfished (Schirripa and Legault, 
1999; SEDAR 1 ). Regulations that 
decrease the total allowable catch 
and shorten the recreational season 
have been enacted over the last sev- 
eral decades to reduce the harvest 
of this species and increase stock 
abundance. 
The red snapper is a reef-asso- 
ciated fish that uses reef habitat 
as a resource for both shelter and 
prey (Ouzts and Szedlmayer, 2003; 
Szedlmayer and Lee, 2004; Piko and 
Szedlmayer, 2007; Gallaway et ah, 
2009). Age-0 red snapper begin to use 
reefs shortly after they settle out of 
the plankton and move to available 
low-relief, structured habitat (Work- 
man and Foster, 1994; Szedlmayer 
and Howe, 1997; Szedlmayer and 
Conti, 1999; Szedlmayer and Lee, 
2004). These new recruits quickly 
outgrow their initial benthic habi- 
tats and search for larger structured 
1 SEDAR (Southeast Data, Assessment, 
and Review). 2009. Stock assessment 
of red snapper in the Gulf of Mexico: 
SEDAR update assessment. Report of 
the update assessment workshop;, 24-28 
August, 2009, 143 p. Miami, FL. NMFS, 
SEFSC, NOAA, Miami, Florida. [Avail- 
able from http://www.sefsc.noaa.gov/ 
sedar.] 
habitats by fall after the spawning 
season (Szedlmayer and Conti, 1999; 
Szedlmayer and Lee, 2004; Szedl- 
mayer, 2011). After this initial re- 
cruitment, the presence of age-1 and 
older snapper, through predation and 
competitive exclusion, may limit the 
immigration of new recruits to reef 
structure (Bailey et ah, 2001; Piko 
and Szedlmayer, 2007; Gallaway et 
ah, 2009; Mudrak and Szedlmayer, 
2012). 
The substrate in the northern Gulf 
of Mexico is predominately mud and 
sand and has comparatively few natu- 
ral reef areas (Parker et al., 1983; 
Kennicutt et al.,1995; Dufrene, 2005). 
The lack of naturally occurring reefs 
has stimulated the deployment of 
artificial reefs (e.g., decommissioned 
military tanks and concrete pyra- 
mids) by state agencies, private fish- 
ermen, and scientists to increase the 
availability of reef habitat. Several 
permit areas have been established 
off the coast of Alabama, where an 
estimated 15,000 artificial reefs have 
been deployed (Minton and Heath, 
1998). The deployment of new reefs 
each year continues to add or replace 
reefs lost to major tropical storms. 
The effect of artificial reefs on reef 
fish populations has been considered 
for decades. Bohnsack (1989) sug- 
gested that artificial reefs may sim- 
ply aggregate fishes, making resident 
species easier to harvest and may ul- 
timately decrease their populations. 
A second possibility is production 
enhancement, where reefs provide 
some limiting factor (e.g., habitat) 
that allows for an increase in the 
