The 2010 Deepwater Horizon oil spill, the largest accidental oil spill in American history, occurred off the U.S. coast of Louisiana in the Gulf of Mexico. The ruptured wellhead released 172 million gallons of oil into the Gulf (Griffiths 2012). As part of the emergency response effort, managers applied an estimated 1.8 million gallons of the dispersants Corexit 9527A and 9500A to the spilled oil (National Commission on the BP Deepwater Horizon Oil Spill and Offshore Drilling, 2011). Coastal residents and businesses began asking questions about where the oil went and how oil and dispersant affected wildlife and public health. Agencies closed fishing areas, tourists cancelled reservations, and resource managers worked to protect resources and assess damages from the spill.