BIOMASS, DENSITY, AND SIZE DISTRIBUTIONS OF FISHES ASSOCIATED WITH A LARGE-SCALE ARTIFICIAL REEF COMPLEX IN THE GULF OF MEXICO

The Freeport Sulphur Mine Artificial Reef (FSMAR) is a decommissioned oil and gas platform and serves as the largest artificial reef complex in the northern Gulf of Mexico (NGOM). Given the increasing numbers of artificial reefs in the NGOM, yet the paucity of information that exists, the goals of this study were to evaluate the biomass, density, and size structure of fishes associated with FSMAR. Mobile acoustic surveys were used to assess both horizontal and vertical distribution and abundance of fishes associated with the shallow water (16 m depth) reef complex and adjacent soft-bottom habitats extending 1 km from the reef complex. Highest acoustic estimates of fish biomass and density were found directly over the reef with a five-fold and 16-fold decrease at 10 and 30 m distances from the structure, respectively. In addition, fish biomass and density were highest in the bottom water column (> 10 m), followed by mid-water (6.1-10 m), and lowest in the upper water column (1.5-6 m). Findings suggest that fish distribution at the FSMAR is much greater than previously surveyed decommissioned oil and gas platforms and natural reef habitats in the NGOM. We consider the potential importance of this unique nearshore complex as an important habitat to fishes utilizing nearby estuarine and inner shelf systems in the NGOM.