Absolute Abundance Estimates for Red Snapper, Greater Amberjack, and Other Federally Managed Fish on Offshore Petroleum Platforms in the Gulf of Mexico

Abstract

Offshore petroleum platforms provide habitat utilized by an array of reef fish that are valuable to both commercial and recreational fishers. However, thousands of offshore platforms have been decommissioned in the Gulf of Mexico over the past decade, with many of the removals being accomplished using explosive severance methods. Here, we estimate the impact of platform removal in the Gulf of Mexico on five stocks of federally managed reef fish based on the percentage of each stock that is resident on platforms. We conclude that the gulfwide impact of removal will be relatively minor (1% to 8% of the estimated stock abundance) for four species, Red Snapper Lutjanus campechanus, Gray Triggerfish Balistes capriscus, Vermilion Snapper Rhomboplites aurorubens, and Cobia Rachycentron canadum. In contrast, losses for the Greater Amberjack Seriola dumerili stock would potentially represent 45% of the known stock. An alternative explanation is that the actual abundance of Greater Amberjack is much larger than the most recent stock size estimate; in either case, we suggest this issue needs further examination. Removal impacts could also be significant for reef-fish fisheries (especially the Red Snapper fishery) in areas where platforms are presently abundant but other high-relief natural or artificial reefs are not present. Removal of the platforms from these areas will greatly impact the local fisheries.