Irving Mendelssohn, a Louisiana wetland ecologist, knows what won’t work if and when the oil slick in the Gulf reaches his marshy coastline.
Unfortunately, he’s not sure what will.
“The most important thing is that you don’t send hundreds of people walking into the wetlands, pushing that oil into the soil,” he said. “You can’t have people stomping around in their boots. And you don’t want machines like tractors pushing the oil into the soil. That would definitely kill the vegetation.”
All other “remediations” are problematic, too, Mendelssohn said. As a professor at Louisiana State University who specializes in the effects of oil on wetlands, he’s been advising the National Oceanic and Atmospheric Administration on cleanup of the massive slick edging toward the mainland. The oil has now reached the sandy beaches of Louisiana’s barrier islands, even as crews struggle to contain more than 200,000 gallons of oil gushing every day from BP’s exploded Deepwater Horizon rig in the Gulf of Mexico.
Bioremediation, or breaking down the oil with bacteria, wouldn’t work well in Louisiana because the coastal wetlands are flooded with water, Mendelssohn said. Setting the marshes on fire or flushing them with low-pressure hoses could be effective in plots of 20 or 30 acres, he said, but those methods aren’t feasible in larger areas.
“Would you want to burn hundreds of thousands of acres?” Mendelssohn asked. “That’s a tremendously hard call.”
There are no good cleanup options for the orange-colored slick the size of Delaware, just as there were none for the Exxon Valdez tanker spill off Alaska in 1989, the Amoco Cadiz tanker spill off Brittany, France, in 1978, or the platform blowout in the Santa Barbara Channel in Santa Barbara, Calif., in 1969.
Robert Bea, a University of California, Berkeley, professor of civil environmental engineering who spent nearly 60 years in the oil business, was sent as a troubleshooter to all of those and several dozen more onshore and offshore spills.
In Santa Barbara, he recalled, people tried to mop up the black tide on the beaches with paper towels and bales of straw. “It’s more sophisticated today, but it’s the same damn thing. Unfortunately, we have not progressed very far since the miserable experiences of Santa Barbara and the Exxon Valdez.”
In the sensitive marshes of the California’s Bay-Delta 35 years later, Bea said, workers used buckets to scoop up the mess from a 60,000-gallon pipeline oil spill.
“We killed the marsh,” he said.
Along the coast of Brittany, some of the salt marshes there are still recovering from being trampled after the Amoco Cadiz accident, in which the supertanker split in two, spilling 68 million gallons of oil. Other marshes were bulldozed and the topsoil was carted away, leaving areas below water unable to regenerate. Effectively, studies show, the excavated marshes will never come back, while untreated areas are doing fine.
The Exxon Valdez spill, totaling 11 million gallons of oil, is still the largest in the U.S. and arguably one of the worst anywhere in terms of the environmental damage it caused. It covered more than 1,300 miles of wild coastline along Alaska’s Prince William Sound with black sticky goo.
John Robinson, a Santa Barbara resident who was NOAA’s scientific adviser on the Exxon Valdez spill, recalled this week how he advised the U.S. Coast Guard to use high-pressure hoses to blast steaming hot water on the rocky shores of Alaska. It enabled the cleanup workers — 11,000 in all — to push the oil back into the ocean where it was corralled and skimmed off behind booms. But it “cooked” everything in sight.
Robinson said he feared that if the oil was not removed, it would swirl around and cause damage elsewhere.
“In the end, it was proven pretty clearly that we did the wrong thing,” he said. “We were approaching sterilization of the coast with that kind of equipment. It turned out to be a mistake. This kind of aggressive cleanup does nothing but delay the eventual recovery that nature is going to do anyway.”
It turns out that driving oily sand below the tide line, where many plants and animals had escaped the spill, the blasts of hot water only made matters worse, according to a report by NOAA in 1991.
“Sometimes, the best thing to do in an oil spill is nothing,” the report concluded.
The public, however, wants a reason to hope. In a 1993 report, the state of Alaska said that benefits to fishing and tourism outweighed the disruptions of the Exxon Valdez cleanup. Officials were willing to accept some damage in return for removing as much oil from shore as fast as possible, the report said.
And in a 10-year study on the effects of the spill, Bowdoin College researchers concluded that 90 percent of the plants and animals in the Exxon Valdez spill zone had recovered by mid-1990, in part because of the cleanup and in part because of natural forces.
Even the heavily oiled and treated shorelines of Prince William Sound have proved to be quite resilient: They appear today much as they did before the spill. At the same time, according to NOAA, deposits of oil linger underground, mussels are still contaminated, and once-rich clam beds have not yet recovered.
Robinson said his own experience has made him a skeptic. When the Exxon Valdez cleanup was in full swing, he fought for nine areas — totaling less than a mile of coast — to be set aside and not cleaned. Within a few years, he said, “It was clear that the areas that had not been cleaned were faring a lot better in terms of their recovery. The areas that were cleaned were in much worse shape.”
As the head of NOAA’s Hazardous Materials Response Team, which he founded in 1976, Robinson oversaw about 100 oil spill cleanups. “I can’t think of any good example where a cleanup has been anything other than useless. It causes more damage than not doing anything at all. Once the genie gets out of the bottle, there’s no getting it back in. That seems to be proving itself once more in New Orleans.”
Bea is more of an optimist, even as he notes that cleanups typically capture only 10 percent of spilled oil.
“If you don’t do anything, you don’t learn anything,” he said.
Of course, it's best to keep the genie in the bottle, Bea said. In 2002, he wrote a study urging oil companies to adopt a system of organizational checks and balances to guard against accidents at deepwater rigs.
Right now in the Gulf, more than 8,000 workers are attempting to contain the spill and prevent it from reaching the mainland, and another 2,500 are on call. Nearly 300 boats are assisting in cleanup efforts. More than 30 miles of floating booms have been laid along the Gulf Coast, and 10 staging areas have been set up onshore. To date, nearly 2 million gallons of watery oil have been recovered.
Just how bad the spill will be onshore depends on how much oil moves in, how much it has weathered or degraded over time and how long it stays. Wetland plants can survive a light oiling. But if the plants get coated every time the tide comes in, Louisiana will likely lose large pieces of its coast to the spill, Mendelssohn said.
“What is really frightful and very scary is, when the plants die, the top 12 inches of soil where the roots are will start to die and collapse like a balloon,” Mendelssohn said, adding that when the soil loses volume, it sinks, giving rise to excessive flooding. New seeds cannot re-establish, he said, and “before you know it, you have land loss.”
Louisiana has 40 percent of the remaining wetlands in the lower 48 states. Even before the spill, the state was losing wetlands to storms and erosion at the rate of 25 square miles per year.
“When the Louisiana wetlands are affected,” Mendelssohn said, “it’s both a regional and a national impact.”