On Tuesday, a cruise through the Barataria Bay marsh revealed thin shoots growing up out of the oiled mass of grass. Elsewhere, there were still gray, dead mangrove shrubs, probably killed by the oil, but even there new green growth was coming up.
“These are areas that were black with oil,’’ said Matt Boasso, a temporary worker with the Louisiana Department of Wildlife and Fisheries.
As crude from a blown-out BP well oozed toward the marshes after an April oil-rig explosion, specialists had feared it would kill roots in marsh grass, smother the mangroves, and ultimately dissolve wetlands that plant life was holding together. State, federal, and BP cleanup efforts were focused on preventing that from happening by burning and skimming the oil, blocking it with booms and sand berms, and breaking it up with chemical dispersants.
Whether it is a triumph of cleanup work, the marshes’ resiliency, or both, scientists have reported regrowth of grasses; black mangrove trees; and roseau cane, a lush, tall cane found in the brackish waters around the mouth of the Mississippi River.
“The marsh is coming back,’’ said Alexander S. Kolker, a marsh specialist and coastal geologist in Cocodrie, La., with the Louisiana Universities Marine Consortium. “Sprigs are popping up.’’
Kolker is working with a National Science Foundation team looking at the effect of the BP oil spill on Louisiana’s vast but severely stressed marshland — also known as the Cajun prairie — where trappers, shrimpers, and alligator hunters have made their living for generations. Louisiana, the state worst hit by the oil spill, is home to the vast majority of the northern gulf’s marshland.
Coastal Louisiana is covered in a thick mat of salt marshes that thrive on the edge of the Gulf of Mexico, where land merges with the sea. The marshes provide life support for fauna and flora in the gulf, said Bob Thomas, a zoologist at Loyola University, and up to 90 percent of commercial fisheries depend on them for fish development.
