COCODRIE, La. — Oil gushed into the Gulf of Mexico unabated Saturday, and officials conveyed little hope that the flow could be contained soon, forcing towns along the Gulf Coast to brace for what is increasingly understood to be an imminent environmental disaster.
The spill, emanating from a pipe 50 miles offshore and 5,000 feet underwater, was creeping into Louisiana’s fragile coastal wetlands as strong winds and rough waters hampered cleanup efforts. Officials said the oil could hit the shores of Mississippi and Alabama as soon as Monday.
The White House announced that President Obama would visit the region on Sunday morning.
Adm. Thad W. Allen, the commandant of the Coast Guard, who is overseeing the Obama administration’s response to the spill, said at a news conference Saturday evening that he could not estimate how much oil was leaking per day from the damaged underwater well.
“There’s enough oil out there that it’s logical it’s going to impact the shoreline,” Admiral Allen said.
The imperiled marshes that buffer New Orleans and the rest of the state from the worst storm surges are facing a sea of sweet crude oil, orange as rust. The most recent estimate by the National Oceanic and Atmospheric Administration said the wreckage of the Deepwater Horizon rig, which exploded on April 20 and sank days later, was gushing as much as 210,000 gallons of crude into the gulf each day. Concern is mounting that the flow may soon grow to several times that amount.
The wetlands in the Mississippi River Delta have been losing about 24 square miles a year, deprived of sediment replenishment by levees in the river, divided by channels cut by oil companies and poisoned by farm runoff from upriver. Hurricanes Katrina and Rita took large, vicious bites.
The questions that haunt this region are how much more can the wetlands take and does their degradation spell doom for an increasingly defenseless southern Louisiana?
Many variables will dictate just how devastating this slick will ultimately be to the ecosystem, including whether it takes days or months to seal the leaking oil well and whether winds keep blowing the oil ashore. But what is terrifying everyone from bird watchers to the state officials charged with rebuilding the natural protections of this coast is that it now seems possible that a massive influx of oil could overwhelm and kill off the grasses that knit the ecosystem together.
Healthy wetlands would have some natural ability to cope with an oil slick, said Denise Reed, interim director of the Pontchartrain Institute for Environmental Sciences at the University of New Orleans. “The trouble with our marshes is they’re already stressed, they’re already hanging by a fingernail,” she said.
It is possible, she said, that the wetlands’ “tolerance for oil has been compromised.” If so, she said, that could be “the straw that broke the camel’s back.”
To an untrained eye, the vast expanses of grass leading into Terrebonne Bay, about 70 miles southwest of New Orleans, look vigorous. Locals use boats as cars here, trawling though the marsh for shrimp or casting for plentiful redfish. Out on the water, the air smells like salt — not oil — and seabirds abound and a dolphin makes a swift appearance.
But it is what is not visible that is scary, said Alexander Kolker, a professor of coastal and wetland science at the Louisiana Universities Marine Consortium. Piloting a craft through the inland waterways, he pointed out that islands that recently dotted the bay and are still found on local navigation maps are gone. Also gone are the freshwater alligators that gave the nearby town Cocodrie its name — French settlers thought they were crocodiles.
All evidence, he says, is that this land is quickly settling into the salt ocean.
The survival of Louisiana’s coastal wetlands is not only an environmental issue here. Since successive hurricanes have barreled up from the gulf unimpeded, causing mass devastation and loss of life, just about every resident of southern Louisiana has begun to view wetlands protection as a cause of existential importance. If the wetlands had been more robust when Hurricane Katrina’s waters pushed up from the ocean, the damage might not have been as severe.
But they were not. Levees holding back the Mississippi River have prevented natural land replenishment from floods. Navigation channels and pipeline canals have brought saltwater into fragile freshwater marshes, slowly killing them, and the sloshing of waves in boats’ wakes has eroded natural banks.
Since 1932, the state has lost an area the size of Delaware. Not all the damage is caused by humans: the hurricanes of 2005 turned about 217 square miles of marsh into water, according to a study by the United States Geological Survey.
Garret Graves, director of the Governor’s Office of Coastal Activities, said that since Hurricane Katrina, extraordinary efforts at restoration had been made and, to some extent, had slowed the decline. But, he said, a severe oil dousing would change that.
“The vegetation is what holds these islands together,” Mr. Graves said. “When you kill that, you just have mud, and that just gets washed away.”