Syc and Szedlmayer: A comparison of size and age of Lutjanus campechanus with the age of artificial reefs in the Gulf of Mexico 
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from 1992 to 2007. The oldest reef (1992) was closest 
to a 2010 reef that we sampled, and many of the arti- 
ficial reefs deployed in 2004 and 2007 were within 1.7 
km of reefs in all 3 reef ages that we sampled in our 
study (Fig. 4). No significant correlations were detected 
between distance to other reefs and abundance (Pear- 
son’s r=-0.045, P=0.781), or mean age of red snapper 
(Pearson’s r=0.026, P= 0.88; Fig. 5). 
Discussion 
Evidence for production and attraction 
Our study showed that older red snapper were associ- 
ated with older artificial reefs. Previous studies have 
compared artificial reef age with estimates of density 
and size of resident reef fishes but have not examined 
reef fish age. For example, densities of reef fishes and 
larger sparids ( Diplodus sargus, Diplodus bellottii, and 
Diplodus vulgaris ) have been reported to be significantly 
higher at older habitats (Lindberg et al., 2006; Santos 
et al., 2011). Because length varies directly with age 
with these species up to the age of 3 years (Gordoa and 
Moll, 1997), it is likely that their age also increased with 
reef age as was observed with red snapper in our study. 
The relation between reef age and fish age shown in 
our own and these other studies, along with the long- 
term residence of red snapper on artificial reefs shown 
in previous studies (Schroepfer and Szedlmayer 2006; 
Topping and Szedlmayer, 2011a), supports the hypoth- 
esis that artificial reefs enhance the production of red 
snapper (Szedlmayer and Shipp, 1994; Szedlmayer, 
2007; Gallaway et al., 2009). If artificial reefs enhance 
a population and experience no fishing pressure, Powers 
et al. (2003) estimated that such reefs could increase 
production by 6.45 kg wet weight/10 m 2 in the first year 
after their deployment. Because the locations of the 
reefs in our study were not published, fishing mortality 
was limited and therefore had the potential to increase 
production. 
It was also clear that attraction of fish plays an im- 
portant role in the function of these artificial reefs. 
For example, fish older than the age of the reef were 
