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
Montara oil spill seaweed farmers and fishermen had been affected by the oil spill. PTTEP Australia has stated that independent studies published by the Australian Department for the Environment found that 98.6 per cent of Montara oil stayed in Australian waters, and that the company has received "no credible evidence of damage to the environment in West Timor." East Timorese President, Dr José Ramos-Horta, said that the Australian government and the Thai company that own the platform are responsible for the spill, and that he will seek compensation for damage caused by the spill to his country's environment. Ramos-Horta called for Australian environmental