Guardian: When Hurricane Katrina wrecked the Louisiana coast, it wasn’t the wind that created disaster in itself, but the floods which surged over the levees and washed across the wetlands in its wake. Now the region has been hit by a second disaster, an oil slick. A different kind of flood this time, a thick, black flood of crude oil that approaches the coastline, threatening the wildlife and the fragile ecosystem of the wetlands of Louisiana and the Mississippi Delta. For years I lived …