The introduction and proliferation of offshore oil and gas platforms in the northern Gulf of Mexico (Gulf) has undoubtedly affected the marine ecosystem. There are approximately 4,000 platforms in the federal waters of the Gulf. Because a mud/silt/sand bottom with little relief or hard-substrate dominates the northern Gulf, especially west of the Mississippi River Delta (Delta), any additional hard-substrate provided by platforms could prove significant.Although platforms provide an estimated 11.7 km2 (or 0.4%) of the total "reef" habitat in the northern Gulf, platform significance may be enhanced by the vertical relief of their substrate, which extends from the bottom through the photic zone to the surface. Because fish populations are usually limited by available energy, recruitment, or habitat, it is important to determine if platforms: 1) serve as new or additional spawning habitat; 2) provide critical habitat for early life history stages; or 3) influence energy flow through the ecosystem by aggregating prey.