VENICE, La. -- As fingers of oil from the massive Deepwater Horizon spill continue to expand along the Gulf Coast, officials are scrambling to protect marshes and beaches. But there's only so much that can be done, experts say.
So far, efforts to keep the oil offshore have centered on two strategies: booms and berms.
For weeks, workers have encircled barrier islands in the Mississippi River Delta with floating containment booms -- long, linked sections of PVC fabric -- designed to keep oil from reaching the marshes, with mixed success. More recently, Louisiana officials are undertaking a new project to construct 6-foot-high sand berms on the seaward side of barrier islands fringing the delta to protect sensitive shorelines, fish nurseries and other wildlife habitat further inland.
But with such large volumes of oil spreading through the Gulf -- between 12,000 and 25,000 barrels continue to spew each day from BP PLC's damaged well 50 miles offshore -- many experts doubt whether such efforts will be effective.
The expanding slick has fouled more than 140 miles of Louisiana coast and is now washing ashore on Mississippi and Alabama's sandy barrier islands and points farther east, threatening northwest Florida's summer beach tourism season (Land Letter, June 3).
The encroaching oil continues to arrive despite the government's deployment of about 3 million feet of containment boom at a cost of around $60 million.
"If it's widespread enough, there's no way to keep it away," said John Anderson, a professor of coastal geology and oceanography at Rice University in Houston. "We don't have enough booms to stretch from Louisiana to south Florida."
And last week's beginning of hurricane season only increases the odds of more oil reaching land.
"If we have a tropical storm that really starts to break the oil up, we would have to ... prioritize, putting booms in one area but not another," Anderson said. "This is a very serious catastrophe, and I don't think even professionals have grasped the sheer magnitude of this event."
Floating booms already have proven difficult to manage at such a large scale. They are easily shifted by wind and waves, and sometimes become unmoored and float away, or break apart. During a boat trip through the Mississippi Delta's marsh islands last Tuesday, wildlife recovery teams came upon a boom drifting in open water, far from the island it was supposed to protect.
And with thousands of miles of shoreline to guard, there simply is not enough boom to go around -- or enough manpower to make sure it stays put.
"These berms are less effective than we had hoped they would be," said Dawn Lavoie, the U.S. Geological Survey's science coordinator for the Gulf Coast. "Louisiana is a huge coastline if you think about it, and it would take a huge amount of manpower, and I don't know how anybody's going to be able to keep the oil off, to be honest. It's just a huge amount of oil that's available to come in."
The newest defense, spearheaded by the state of Louisiana, involves constructing 6-foot sand berms in front of barrier islands to block the oil's path ashore. The first phase, which involves the construction of 45 miles of berms along the Chandeleur Islands within Breton National Wildlife Refuge on the east side of the delta and along another stretch of barrier islands on the west side, will provide a key test of whether the berms are effective.
"We're going to be closely monitoring the first projects, and at any time the state can come back to us and ask us to evaluate the other reaches they've proposed," said Pete Serio, chief of the regulatory branch of the Army Corps of Engineers' New Orleans division. "We may find that the other reaches are viable. We're just not sure yet."
The corps approved the initial six berms, out of the 19 the state had proposed, because those segments had the least environmental impact and the highest potential for success, Serio said.
"Obviously, you can't be 100 percent certain about anything, and if a hurricane comes through, everything's off the board then," he said. "Obviously, they're not going to stand up to a hurricane. But we felt comfortable that these six reaches could be successful."
The corps modified Louisiana's original 128-mile proposal to require breaks in the berms so that the natural interchange of Gulf waters and estuary waters will not be impeded. Tides provide an important hydrological function that helps maintain salinity levels in brackish waters, and scientists had expressed concern that the original proposal, which envisioned an unbroken wall of sand skirting the delta, would interfere with the ebb and flow of the tide.
The sand to be used to build the berms will be dredged from three areas "a good distance away" from the construction sites to lessen the environmental impact, he said.
BP has agreed to pick up the $360 million tab for the structures and on Monday pledged an initial payment of $60 million to launch the project. The rest of the money will be paid in stages as the berm-building proceeds, said BP spokesman John Pack.
"We are committed to doing everything we can to protect the coastline and reduce the impact of the oil and gas spill in the Gulf of Mexico," BP Managing Director Bob Dudley said in a statement. "We understand that the United States Coast Guard and the State of Louisiana want this project to proceed with urgency, so we want to ensure that funding is immediately available to begin construction of the berms."
The Corps of Engineers is expected to approve the monitoring plan for the project today, clearing the way for construction to begin. The corps will keep an eye on the dredge-and-fill operation around the clock to make sure it complies with permit requirements, Serio said.
Beyond the anticipated protection of coastal areas, the berm project carries an added benefit of helping restore sand to already degraded barrier islands. The Chandeleurs, for example, lost 80 percent of their landmass during hurricanes Katrina and Rita in 2005. The area is not included in a federal program aimed at restoring barrier islands after the hurricanes, and scientists say they welcome the influx of new sand to the wildlife refuge.
But it is only a temporary fix and will do little to contribute to long-term coastal restoration, scientists said.
"If the dredges will follow the conditions that are set out in the permit, I think it will do no harm," said Lavoie of USGS, who added that the corps consulted with her agency as well as the Fish and Wildlife Service on the project. "But this is going to wash away pretty quickly. This will last until the first storm comes, then it will get washed away because there's nothing holding it there."
Yet even with work set to begin in days, some remain worried that the berms, whose construction could take six months, will not be in place fast enough to protect against the advancing oil, especially with tropical storms on the horizon.
"The problem is timing," Lavoie said. "For this to be effective, it needed to be done weeks ago."
Another concern is that if the berms do absorb the oil, the contaminated sand will be ruined for future restoration efforts. "There's a limited sand supply," Lavoie said.
Anderson, while not familiar with the details of the berm project, offered that the strategy could be effective if the Gulf of Mexico's circulation patterns are taken into account and erosion can be minimized.
"Barrier islands are very effective at protecting inland areas from storms by absorbing some of that hurricane energy offshore, but in terms of the berms' ability to capture oil, that's difficult to say," he said. "These are major undertakings, and they really need to be looked at carefully. There's a tendency for people to want to take the quick fix."
The remaining mess
Yet even with hundreds of miles of booms and berms in place, oil will continue to reach land, and experts say there are no clear answers for how best to clean up oil-soaked areas.
Every option, from removing oiled soils to controlled burns to enhancing the oil-consuming capacity of microbes in the soil, has its drawbacks.
For instance, biostimulation -- adding nutrients to the soil to accelerate microbe activity so that the oil degrades faster -- will only work if enough oxygen is available in the soil, said Irv Mendelssohn, a plant ecologist with Louisiana State University who specializes in coastal ecosystems.
"Just the addition of nutrients might not increase the degradation rate because it's not the nutrients or the bacteria that's limiting to the deterioration, it's oxygen," he said. And trying to physically remove contaminated wetland soils could just push the oil deeper into the ground, he added.
Nevertheless, all cleanup options should be considered, Mendelssohn added. "One thing we've learned is that no two oil spills are alike," he said. "A cleanup approach that works in one case might not in another."
In some areas, the best option might be no action at all, especially if the marsh will recover on its own, he added. "I realize it's difficult to accept the no-action approach, because people want something to be done," he said. "But if cleanup has the potential for doing more damage than the oil spill itself, then it's better to take no action and to let the oil degrade on its own."
Pack, the BP spokesman, said the company has committed $500 million for the Gulf of Mexico Research Initiative, which will examine the long-term effects of the spill on wetlands, beaches and wildlife. A team from LSU is already beginning to study those impacts, he said. "We're committed in activity but also in dollars to making this right," he said.
Anderson, who helped respond to a 1979 oil spill off the coast of Mexico that spread northward to Florida -- the second-largest Gulf spill behind the April 20 BP disaster and also caused by a well blowout -- said he suspects the Deepwater Horizon cleanup effort will last years.
"With the rig blowout in Mexico in '79, it was significantly smaller, and it took years to get it out of the system," he said. "And that spill was just a fraction of the oil they're talking about now.
"This is just an unprecedented event," he continued. "I don't know many oceanographers who are confident that we're going to be able to clean this thing up. It's a little bit like throwing water on a forest fire."