"So how much is the Gulf of Mexico worth? And how much of its value is at risk from the BP oil spill that started after the Deepwater Horizon rig exploded April 20? We have an answer, or at least an estimate for the value of one critical piece of the Gulf Coast, from a report by Earth Economics executive director and Gund Institute for Ecological Economics Fellow, David Batker, released just before the spill. The value of the Mississippi Delta's ecological services is between $12 billion and $47 billion annually. Environmental Defense Fund, which helped fund the study and is promoting Batker's results, notes that the value is arguably greater than BP's market capitalization before the disaster ($189 billion, though that has dropped precipitously since the spill)."