Oil is seen on river cane at the mouth of the Mississippi River south of Venice, La. Tuesday, May 18, 2010.  (AP Photo) (CBS/AP)  It may be the most disturbing site yet: the first heavy sludge now oozing into the marshes of Louisiana as the slick continues to grow in size out in the gulf. CBS News correspondent Kelly Cobiella reports it’s an ominous sight. The oil is thick and black and stretches about a quarter mile down a beach. It goes beyond the booms into the sensitive marsh lands which are home to migratory birds. Louisiana Gov. Bobby Jindal flew over it Tuesday. “This wasn’t just sheen, we were seeing heavy oil out there,” Jindal said. “This wasn’t just tar balls. It shows you how quick the oil showed up.” When CBS News tried to reach the beach, covered in oil, a boat of BP contractors with two Coast Guard officers on board told us to turn around under threat of arrest. Coast Guard officials said they are looking into the incident. The impact on wildlife is unclear. Government officials say that 162 sea turtles have died, about half a dozen bottle nose dolphins have died. The sea turtles have not been thoroughly examined yet but federal officials say this seems related to the oil spill. And they admit they have no idea what’s happening in the deeper waters because they can’t watch it. …

Heavy Sludge Oozes into Marshes of Louisiana