As we approach the one-year anniversary of the April 20th Deepwater Horizon disaster, an LSU coastal scientist says Louisiana's marshes are in better shape than once feared.   Professor Ed Overton says he thought a major portion of Louisiana's coast would have been damaged as millions of barrels oil spewed from the damaged rig.  Overton says he noticed re-growth of marshland during a recent fly over, but areas of northern Barataria Bay may never come back.    Overton says some of the oil was weathered by the time it reached Louisiana's coast.   He says chemical dispersants used around the oil spill site might have also helped.