From Fox News: On April 20, 2010, the BP oil drilling rig Deepwater Horizon exploded and released 152 million gallons of oil into the Gulf of Mexico. During the cleanup, BP released at least 2 million gallons of chemical "dispersant" into the gulf to break up the floating oil. The chemical dispersants released are solvents that are quite toxic in their own right.
Commercial fishers have since been discovering large numbers (hundreds of pounds) of eyeless shrimp and crabs and malformed fish in the gulf.