Decision Making During the Crisis
This report from the August 13 issue of Science provides an interesting behind-the-scenes view of how scientists, executives, and government collaborated on finding solutions.
How BP came to spray 1.1 million gallons of chemical dispersants a mile beneath the ocean surface is a story of scientists turning to desperate measures during desperate times. And the government's decision to let BP do so, among the most gutsy calls of the entire Deepwater Horizon saga, was a classic case of pitting the devil you know against the devil you don't.
Roughly a week after the magnitude of the gusher became clear in late April, former Exxon-Mobil scientist Gerard Canevari suggested that BP might try spraying chemicals called dispersants right at the billowing wellhead. Dispersants are usually used in small quantities on the surface of the ocean to break up slicks. Canevari's idea would mean releasing giant amounts of the fairly nasty chemicals in the cold and high-pressure world of the ocean floor, something that had never been tried. "At first we were going, Yeah, right," recalls Charlie Henry, a top scientist on Gulf of Mexico issues for the National Oceanic and Atmospheric Administration (NOAA). "It was out of the norm"—a massive proposed undersea experiment.
But, he says, the unprecedented nature of the problem meant nothing was off the table. While outlining the pros and cons on white boards in NOAA's New Orleans office, says Henry, the basic tradeoff seemed clear. Every drop of oil that made it to the surface was a potential threat to coastal ecosystems, fish, and marine mammals. Dispersants, which are mostly detergents, break up globs of crude into microscopic droplets that are more readily devoured by microbes. So keeping as much oil as possible below the surface would give microbes a leg up in eating the oil. And injecting dispersants into the hot, vigorously mixing oil of the busted riser would presumably mean they would work especially effectively. Smaller quantities would then presumably be needed at the ocean surface.
Some drawbacks emerged during a conference call with 25 industry and academic scientists arranged by NOAA in early May: The risks to undersea marine life—eggs, larvae, fish, coral, and other bottom dwellers—were largely unknown. One possibility was particularly frightening: Giving microbes a feast of hydrocarbons might massively increase their numbers, starving the water column of oxygen and creating dead zones.
So government scientists proposed a three-tiered plan to try the undersea injection as safely as possible. First, teams across the country began adapting existing undersea models of oil plumes to predict how they might move, referencing data on nearby sea life from the Department of the Interior. Second, they required that BP conduct aggressive monitoring, including ocean surface-to-floor water sampling, toxicity tests using zooplankton, and tests with fluorometers, which would continuously track the oil droplets. And if the dispersant injection created unexpected effects during tests, an "adaptive management" plan would enable the feds to halt the procedure immediately.
The Environmental Protection Agency (EPA) and the Coast Guard agreed to the procedure on 15 May. "I don't think I've had to make a harder decision," EPA Administrator Lisa Jackson told reporters at the time. BP deployed a specially built tube with tiny holes that was clamped in place to release the chemical right at the spurting pipe.
On 27 May, the first real vetting of the new approach came at a meeting of scientists culled largely from academia and the nonprofit sector, hastily organized by NOAA. The outsiders were asked "to second-guess us," says Henry. Chemist Jeffrey Short of Washington, D.C.–based Oceana recalls feeling skeptical on his way to Louisiana State University (LSU). "You don't want me down there; you know what I think about dispersants," he told Nancy Kinner of the University of New Hampshire, the organizer.
But the fluorometry data presented at LSU showed that the dispersant was working and had broken up the big globs into droplets between 1 and 10 micrometers—and the microbial feast wasn't starving the system of oxygen. So after 2 days of intense debate, Short and the rest of the group gave their approval in a report. "I was struck by the fact that all 50 were in agreement that continuing the sub surface injection was the best option in a bad situation," recalls toxicologist Ronald Tjeerdema of the University of California, Davis.
Since then, researchers have by and large stuck with that opinion. NOAA estimates that roughly 409,000 barrels of oil have been dispersed underwater by the technique. Toxicity tests have suggested an acute risk of dispersant-oil mixtures no greater than that of oil alone. Daniels says some of the dispersed oil has risen toward the surface, while some has formed a loose band, or plume, between 1000 and 1300 meters in depth. No negative impacts on deep-sea life have yet been recorded, although NOAA Administrator Jane Lubchenco says one of the worst case scenarios involving longer exposures due to dispersed oil—big losses of spawning bluefin tuna populations—may not be detectable for years. That's led some scientists to suggest that letting the oil rise to the surface would have been a better move, as it could be more easily collected.
Jacqueline Savitz, an environmental scientist with Oceana, says because of the unknown risks of dispersants, it was "a lose-lose" decision—and despite optimistic projections, all the benefits and costs may not be known for decades.
-- Eli Kintisch, with reporting by Erik Stokstad.
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