File photo shows a tri-colored heron covered with oil from the Deepwater Horizon gulf oil spill along Queen Bess Island near Grand Isle, Louisiana

 
File photo shows a tri-colored heron covered with oil from the Deepwater Horizon gulf oil spill along Queen Bess Island near Grand Isle, Louisiana
A tri-colored heron covered with oil from the Deepwater Horizon gulf oil spill is pictured along Queen Bess Island near Grand Isle, Louisiana in this July 17, 2010 file photo. When BP's Deepwater Horizon oil rig exploded and sank in the Gulf of Mexico last April, killing 11 workers, authorities first reported that no crude was leaking into the ocean. They were wrong. One year on, oil from the largest spill in U.S. history clogs wetlands, pollutes the ocean and endangers wildlife, not to mention the toll it has inflicted on the coastal economies of Florida, Mississippi, Alabama and especially Louisiana. REUTERS/Sean Gardner/Files (UNITED STATES - Tags: ANIMALS ANNIVERSARY BUSINESS DISASTER ENERGY ENVIRONMENT)