gas discharge in terms of equivalent barrels of oil. They calculated a gas discharge that's the equivalent of either 1.6 to 1.9 or 2.2 to 3.1 million barrels of oil, depending on the method used. Although the estimate reflects the uncertainty still surrounding the discharge, even the lowest magnitude represents a significant increase in the total hydrocarbon discharge. "These calculations increase the accepted government estimates by about one third," MacDonald said. The ever-shifting small-scale currents in the Gulf likely have dissipated the plumes and the low oxygen zones associated with them, Joye said, making them difficult if not impossible to find at this point in time. Although gliders are a new platform being used, scientists typically search for subsurface features by dropping instruments from research vessels, a process that's analogous to looking for a feature on Earth's surface by randomly dropping instruments from a height of 1,500 meters (about 5,000 feet) in the atmosphere. "It's like searching for a needle in the haystack," Joye said. "We may never know what happened to all of that gas." Joye cautioned against assuming that microbes will rapidly consume the gases released from the well. Undoubtedly, the methane is a feast for them, Joye said, but she also noted that the microbes need nutrients, such as nitrogen, copper and iron. These nutrients are in scarce supply in the Gulf's deep waters, Joye said, and once they are depleted the microbes will cease to grow -- regardless of how much methane is available. "This study