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
Refugio oil spill rest of the Refugio coastline south of the spill. The spill was much smaller than the nearby 1969 Santa Barbara oil spill on January 28, 1969 in which an oil rig blow-out spilled an estimated of crude oil over a ten-day period. The thick crude oil damaged the coats, skin, beaks, and appendages of hundreds of animals. Workers eventually collected 202 dead birds and 99 dead mammals which included at least 46 sea lions and 12 dolphins. The full impact will never be known since animals may travel a distance before succumbing to their injuries. Sixty-five live birds and sixty-three