Depuration of Macondo (MC-252) Oil Found in Heterotrophic Scleractinian Corals (Tubastrea coccinea and Tubastrea micranthus) on Offshore Oil/Gas Platforms in the Gulf

The impetus for this study began on 8 May 2011, when we noted sporadic mortality of colonies of orange—cup corals, Tubastrea coccinea (Lesson, 1829), and green sun corals, Tubastrea micranthus (Ehrenberg, 1834; Cnidaria, Anthozoa, Scleractinia) among colonies of coral that appeared to be in good health at the GI 90 block platforms. Colonies of T. coccinea which appeared to be healthy displayed markedly less tissue regression and were bright orange in color. The morbid polyps were dark brown or black. The corals were collected, transported to the laboratory, and segregated; healthy—appearing corals were placed in quarantine tanks. After 12 h in quarantine tanks, the coral exudate turned the tank water black and the colonies died within 48 h. After observing this unusual behavior, we decided to document subsequent collection events and analyze the discharged oil to determine its source