An oil-soaked bird struggles against the side of an Iron Horse supply vessel at the site of the oil spill off Louisiana on May 9. (AP Photo/Gerald Herbert)
A pod of bottlenose dolphins swims in the oily water of Chandeleur Sound on May 6. Five days later, six dead dolphins were found along the Gulf Coast. Officials were investigating oil’s role in the deaths. (AP Photo/Alex Brandon)
An oil-covered dragonfly, stuck to marsh grass, tries to clean itself May 18 in Garden Island Bay near Venice. (AP Photo/Gerald Herbert)
