The winner of the Best Student Paper award atthe 2011 Annual Meeting was Tara Syc, a student in Steve Szedlmayer’s Auburn University marine fish lab in Fairhope. The title of her talk was “A Comparison of Red Snapper, Lutjanus campechanus, from “old” (2006) to “new” (2009/2010) artificial habitats in the northern Gulf of Mexico.”
Red snapper, Lutjanus campechanus, are a reef associated species that use artificial reefs for both food resources and protection from predators.The species is heavily harvested by both commercial and recreational fishermen and have been managed since 1984. The importance of artificial reefs to the red snapper population has been widely debated for decades. The purpose of my study was to compare the age of red snapper to the age of the artificial reef in an attempt to determine if artificial reefs are allowing for greater red snapper production. If production is occurring, the fish age will be correlated with reef age indicating that fish are settling and staying on the reefs for several years.
A total of 37 artificial reefs were sampled in 2010, with three reef ages examined: 2006 (n =18, 4 year old reefs), 2009 (n = 10, 1 year old reefs), and 2010 (n = 9, 0.5 year old reefs). Red snapper were sampled from April through November 2010 using hook-and-line and a baitedfish trap. The goal of surface sampling was to obtain at least 30 red snapper from each artificial reef. After surface sampling was completed,visual surveys were performed by SCUBA divers to estimate the remaining red snapper densities at reef sites. Once sampling was completed, all fish were brought back to the laboratory and were weighed (0.1 g), measured (mm), and the otoliths were removed for age estimation. The age of redsnapper caught was compared with the age of theartificial reef at the site of capture. Red snappertotal densities per reef were estimated from thecombined captured and diver counted fish.
A total of 1028 red snapper were caught, measured and aged. Mean ± SD age of red snapper showed significant differences whencompared across reef age, with older reefs yielding older fish: 2006 reefs = 3.6 ± 1.2 years, 2009 reefs = 2.0 ± 1.7 years, 2010 reefs = 1.7 ±1.0 years (ANOVA, F2,1025 = 194.23, P <0.0001). A significant positive correlation between fish age and reef age was detected (r2 =0.37, P
< 0.0001). Alternative explanations for the findings were examined including depth differences, distance to other reefs, and growth rates. All of these alternatives were eliminated as factors affecting the age of red snapper on artificial reefs, thereby supporting the conclusion that older reefs are supporting older red snapper. In this study, new artificial reefs were quickly colonized by young fish, and it appears that these fish then stay and grow older as the reef ages.This scenario supports the contention that
artificial reefs in the northern Gulf of Mexico are producing red snapper and not just acting as attractants.