Birds fly over containment booms placed to try to stop oil from reaching the shoreline along the South Pass, south of Venice, La. Oil from a massive rig explosion threatens the region's wildlife. Eric Gay/AP hide caption

itoggle caption Eric Gay/AP

This satellite image taken Thursday shows the oil slick in the Gulf of Mexico as it nears the shoreline, threatening wildlife along Louisiana's fragile islands and barrier marshes. NASA/AP hide caption

itoggle caption NASA/AP