Fish Community Structure on Artificial Reefs in the Northwestern Gulf of Mexico: Potential Impacts of "Rigs-to-Reefs" Programs

Artificial habitat in the northwestern Gulf of Mexico is predominantly comprised of both active and reefed oil and gas platforms. In the last few decades, Texas alone has converted over 140 decommissioned oil and gas platforms into permitted artificial reefs.  Despite the predominance of this habitat type, the associated fish communities remain poorly studied.  Using remotely operated vehicles in 2012 and 2013, we documented fish assemblages surrounding 15 artificial structures (standing, toppled and partially removed platforms, and Liberty Ships) located on the Texas shelf.  Sites were variable in depth (30-84 m), number of structures, and vertical relief. Both structure type and relief influenced species richness and community structure.  However, bottom depth was most influential with a shift in community composition and high diversity observed at approximately 60 m depth.  Supplementary vertical longline surveys also captured the largest Red Snapper in this depth region.  To attain specific management goals, reefing programs should carefully consider the ambient environmental conditions (i.e., depth), as these will most certainly affect the fish assemblage and characteristics of exploited fisheries species. Along the Texas continental shelf, reefing materials at 50-60 m depth may enhance diving experiences and provide the best potential habitat for larger Red Snapper.