There is never going to be a return to normalcy for this area. It has already been under relentless pressure from human activities, to the point where we have a dead zone the size of Rhode Island floating around near this area already due to criminally irresponsible over-use of agricultural chemicals. Way too much pollution has already been coming out of Houston and New Orleans for a long time. BP wasn't satisfied dumping millions of gallons of oil into the water, they also felt it was necessary to dump hundreds of thousands of gallons of unnecessarily toxic dispersant chemicals into the water, mainly for cosmetic PR purposes. Louisiana's marshes are already in serious physical decline from the change in water flow and silt buildup caused by hydrologic engineering in the area.
As far as something being natural, that has little to do with it's ability to destroy ecosystems. Sure, many synthetic chemicals are worse, but don't we have plenty of examples of very harmful natural phenomena? Radiation is natural, for instance. Perhaps you'd like to absorb a couple thousand rems, and see if the naturalness makes a difference in your return to normalcy. Or drink a big glass of oil, why not! It's natural! Several thousand dolphins, sea turtles, jellyfish, fish, sting rays, eels and octopi surely gave that a try recently.