Louisiana's fragile marshes should recover from the Gulf of Mexico oil spill in a matter of months and the environmental impact will be "quite small", a leading expert said.
The upbeat assessment of the damage from the Deepwater Horizon oil disaster came from geologist Ed Owens, a world authority on protecting shorelines from oil spills contracted by BP to lend his expertise to the response effort.
"It's a very, tiny, tiny fraction of what's spilled has actually reached any of the shorelines in the area, which means that the environmental impact in terms of the coastal side of it is quite small," Mr Owens said.
"Because of the nature of the oil, we expect that the recovery will be very much in a matter of months to a year at the most. We're not talking about years or decades here as has been the case for other spills in the US."
The assessment from Mr Owens flies in the face of research from other leading scientists who have warned of a decades-long effect on marine life that could lead to a shift in the overall biological network in the Gulf of Mexico.
Doug Inkley, a senior scientist at the National Wildlife Federation, warned recently that the more than 2,600 dead birds, mammals and turtles found by BP and the US government could be just the tip of the iceberg.
"You could have a (population) crash later because of the failure of many of the young to survive this year," said Mr Inkley. "The impacts on wildlife I expect will last for years, if not decades." But Mr Owens said most of the oil had dispersed naturally in the weeks it took to reach shore and that skimming, burning and the use of dispersants had all contributed as had the strong outflow at the Mississippi River Delta.
"If we measure it in terms of area we are talking way less than 100 hectares, and so the scale of the problem is not as vast as one might think, given the amount of oil that has been spilled," he said.
That area represents some 100 kilometres of Louisiana's 7,000 kilometres of wetland coastlines, a favourite breeding ground for hundreds of species of rare birds and marine animals and an important natural buffer zone for hurricane-prone New Orleans.
The marshes have to be cleaned painstakingly from the water by boat as walking through them or driving on them in vehicles does more damage than the actual crude.