The oil slick that has started sloshing through marsh grass at the southern tip of the Mississippi Delta gives coastal Louisiana a glimpse of what it fears may be its future.
In the last few days, acres of oil have penetrated low-lying islands at the point where the river rolls into the sea, forming a dark red band at the bottom of the roseau cane.
Thick black sludge blocks at least one inlet, and a much larger area off the coast glistens with a rainbow sheen dotted with oil globules, suggesting that more will reach land soon.
"This is what we hoped wouldn't happen but we knew would happen," said Andy Nyman, associate professor of wetland and wildlife ecology at Louisiana State University.
Energy giant BP, accused by the U.S. government of falling short in providing information about the Gulf of Mexico oil spill, was forging ahead on Friday with efforts to contain the crude gushing from one of its undersea wells.
The sight and smell of a slick in fragile wetlands and the ecologically-rich Delta adds urgency to efforts to contain a disaster sparked a month ago when an explosion sank a rig, killing 11 workers, and ripped open the well.
It also casts doubt on a prediction by BP's Chairman Tony Hayward this week that the leak would have only a modest environmental impact.
At the same time, it calls into question the effectiveness of the miles of booms arranged in the water by BP, federal and local authorities in a bid to protect the coastline.
At Blind Bay Louisiana and elsewhere, oil has drifted under or over the booms onto land. Elsewhere, some of the worst-affected islands were entirely unprotected.
In and of itself, the affected area represents just a fragment of the southern tip of the Delta and is dwarfed by the network of waterways that stretch around 100 miles 160 km inland.
But the slick could have an exponential impact on sport fishing, which is a lifeblood of small villages like Venice, Louisiana, and threatens commercial fisheries.
Fishermen and boat owners said they feared what they saw was simply the beginning.
"This could get 100 times worse than what it is today," said fisherman Carey O'Neil, who knows the area intimately as he grew up at an encampment that can only be reached by boat.Read more