PLAQUEMINES PARISH, La.-- When oil gushed out of the Macondo Well for months on end, Louisiana's coast became ground zero for efforts to keep the oil at bay. Even though no new oil has flowed from the well since mid-July, some local officials said residual oil remains in some coastal marshes.
"How long is that going to last is anybody's guess," said Plaquemines Parish President Billy Nungesser. "Hopefully, over the next several months, we'll see it go down, or the amount that we're picking up becomes less and less."
With the failed blow-out preventer on its way to dry land as evidence in the spill investigation, the response is now entering a new phase. Hard boom in other Gulf states is on its way out. Oil spill responders plan to remove millions of feet of hard boom laid out across Mississippi, Alabama and Florida, because they believe it poses more of a risk to the shoreline than any oil that may remain in the Gulf.
Removal of the boom in Louisiana, though, is a bit more measured.
"We're OK with all that boom that's blown up in the marsh, washed up in the bays, being picked up and removed," Nungesser said. "What we asked is that we leave the boom around the critical habitats for the pelicans, the islands, and we continue to work those areas, picking up as much oil as we can that seeps in and out of them."
All of that very much depends on what happens to any oil still out there. On Tuesday, federal scientists released the findings of another study -- this one shows that microbes in the water are continuing to break down oil from the spill. They credit the use of controversial dispersants.
"The whole theory that you would use dispersants is that you would make the particles small enough, so they would be readily consumed by bacteria and, apparently, that is happening," said Steve Murawski, NOAA Fisheries chief science advisor.
With bacteria eating away at the oil, scientists feared it could lead to the creation of dead zones. Despite a 20 percent drop in oxygen levels, though, scientists said they did not see any signs of a spill-related dead zone.
"The oxygen levels have stabilized," Murawski said. "In fact, they are not low enough to be classified as dead zones. They would have to decrease another 70 percent to be classified as dead zones."
Yet, scientists said they still have more work to do. Back in August, the government announced 75 percent of the oil from the spill was gone -- a statement met with widespread skepticism. Federal scientists said they are now preparing to head back out to try to account for all the oil again.