Efforts to stem the Deepwater Horizon oil spill Efforts to stem the Deepwater Horizon oil spill Efforts to stem the "Deepwater Horizon" oil spill were ongoing from the time that the "Deepwater Horizon" exploded on 4/20/2010 until the well was sealed by a cap on July 15, 2010. Various species of dolphins and other mammals (61 casualties), birds (2,095 casualties), and the endangered sea turtles (467 casualties) have been killed either directly or indirectly by the oil spill. The "Deepwater Horizon" spill has surpassed in volume the 1989 "Exxon Valdez" oil spill as the largest ever to originate in U.S.-controlled waters; it is comparable to the 1979 Ixtoc
Oil spill governance in the United States are co-ordinated by the USCG. The National Oceanic and Atmospheric Administration, Office of Response and Restoration (NOAA) works closely with the USCG in providing assistance in technical areas such as Consideration of Alternatives, Oil displacement tracking and risk assessments. Different authorities are responsible for governing oil spill prevention and anticipation depending on the potential sources of the oil spills. A number of executive orders (EOs) and memoranda of understanding (MOU) have established the authorities and agencies responsible for various classes of potential oil spills (Table 1). Table.1 Federal Agency Jurisdiction for oil spill anticipation and prevention duties, by potential sources.