Are There Demographic Differences in the Reproductive Potential of Red Snapper (Lutjanus campechanus) Between Artificial and Natural Habitats in the Gulf of Mexico?

Few quantitative studies of red snapper (Lutjanus campechanus) have been conducted comparing reproductive variables between artificial (AH) and natural (NH) habitats in the Gulf of Mexico.  Reproductive potential is necessary to determine stock status for fisheries management purposes. This study compared the reproductive potential of red snapper between AH and NH.  NHs are areas of relief created from biogenic/geologic processes and are thought to be the historical centers of abundance for red snapper.  Red snapper were collected between 2011 and 2013 from three NH sites and two AH sites. The mean gonadosomatic index (GSI) for each habitat was plotted against time to examine seasonal changes in reproductive potential among sites.  Results indicate red snapper at NH sites exhibited higher mean GSI than those at AH sites during peak spawning season (F=70.0, p <0.0001).  Red snapper at NHs showed 98% maturity, compared to 52% at AHs.  These data support demographic differences in red snapper reproduction between NH and AH.  We hypothesize that the difference exhibited is due to the better energetic condition of red snapper in NHs than in AHs, thus allowing red snapper in NHs to invest more energy in reproduction and less energy towards rapid growth early in life.