Vast amounts of methane in Gulf spill pose threat

NEW ORLEANS - Vast amounts of natural gas contained in crude escaping from the blown Gulf of Mexico oil well could pose a serious threat to marine life by creating "dead zones" where oxygen is so depleted that nothing lives.

The danger presented by the methane has been largely overlooked, with early efforts to monitor the oil spill focusing on the more toxic components of oil. But scientists are increasingly worried about the gas that can suffocate sea creatures in high concentrations.

At least 4.5 billion cubic feet of natural gas - and possibly almost twice that amount - have leaked since April 20. That's based on estimates from the U.S. Geological Survey's "flow team" that 2,900 cubic feet of natural gas are escaping for every barrel of oil.