The Coast Guard and BP have returned to the scene of last year’s Deepwater Horizon disaster after a newspaper reported numerous oily blobs rising to the surface of the Gulf of Mexico a mile from the site. BP is sending a robotic submersible to examine the blown-out well that was cemented last August and declared dead a month later. An initial search turned up no sign of oil at the surface, and BP said in a statement late Thursday that there is no indication that its Macondo well is leaking. But the report by the Press-Register in Mobile, Ala., has incited a flurry of investigatory activity around the well, which blew out on April 20, 2010, in what became the worst oil spill in U.S.