Syc and Szedimayer: A comparison of size and age of Lutjanus campechanus with the age of artificial reefs in the Gulf of Mexico 
467 
many red snapper per unit of volume as more complex, 
smaller structures. For example, an inverse relation 
was shown between the abundance of red snapper and 
the density of offshore platforms — possibly a result of 
greater exposure of young red snapper to predators 
that aggregate around such platforms (Gallaway et ah, 
1999). The higher densities of red snapper on the reefs 
found in our study indicate that these artificial reefs 
may provide red snapper enhanced protection from 
predation as well as greater overall carrying capacity. 
Conclusions 
The significant differences observed in ages of red snap- 
per among artificial reefs of different ages provide sup- 
port for the hypothesis that artificial reefs enhance red 
snapper production. Although it is obvious that red snap- 
per are attracted to artificial reefs, especially as young 
new recruits, and older red snapper may show more 
transient behavior among reefs, it appears that many red 
snapper reside on particular reefs for several years and 
that artificial reefs may allow for higher biomass of red 
snapper by providing additional reef habitat. However, 
at some point, the number of artificial reefs placed in 
the northern Gulf of Mexico may surpass the region’s 
carrying capacity and the addition of more artificial 
structures will no longer increase the population of red 
snapper. Future research that examines the carrying 
capacities of artificial habitats is needed and would 
provide information on when an overall environmental 
carrying capacity for red snapper has been reached. 
Additional fishery-independent studies throughout the 
northern Gulf of Mexico, with methods similar to those 
used in our study, would be useful for making better 
management decisions regarding catch limits for red 
snapper. 
Acknowledgments 
We thank P. Mudrak, M. Piraino, D. Topping, and N. 
Wilson for their help in the field and laboratory. This 
project was funded by the Marine Resources Division, 
Alabama Department of Conservation and Natural 
Resources. This article is a contribution of the Alabama 
Agricultural Experiment Station, and the Department 
of Fisheries and Allied Aquaculture, Auburn Univer- 
sity. All work was carried out under Auburn University 
Animal Care and Use Committee approval, under PRN 
2009-1565. 
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