New York Times: The heavy use of dispersants in the gulf oil spill is unprecedented and troublesome, two top Obama administration officials told a Senate subcommittee on Thursday, but their use has been sharply reduced since late May. In fact, said Lisa P. Jackson, administrator of the Environmental Protection Agency, the daily use of dispersants is down 72 percent since May 26, when her agency and the Coast Guard told BP to use dispersant on the gulf`s surface only as a last resort. “Every …