Platform Removal Observer Program Data Underwater explosives are frequently used in the removal of oil and gas platforms. Since 1987, federal regulations required the use of National Marine Fisheries Service (NMFS) approved observers to perform biological monitoring at the explosive removal of oil and gas structures in the U.S. Gulf of Mexico. In that year, the Platform Removal Observer Program was initiated at the NMFS Galveston Laboratory to meet this requirement. Observers document sightings of sea turtles and marine mammals both before and after detonations, recommend delays in detonating explosives when sea turtles and marine mammals are present inside a predetermined impact zone, record the condition of observed animals, and coordinate retrieval of impacted animals for medical examination, rehabilitation, and necropsy. NMFS observers are required to monitor 100% of all explosive structure removals although special rules govern the use of very small charges. Data sets include information on explosive use, aerial and surface survey effort, sea turtle and marine mammal observations, salvage delays caused by biological monitoring requirements, sea state and visibility.