At this point it's unclear how much of an environmental threat oil spreading from the BP spill will cause, but the federal government is mobilizing thousands of workers to prepare for the worst. They have a potential ally: microbes that have evolved an ability to break down oil that seeps from the ocean bottom. It gets devoured by a variety of bacteria, which eat it by chemically transforming its compounds into useful cellular constituents. "If it wasn't for the natural ability of bacteria to eat oil we would all be knee-deep in the stuff," says bioremediation expert Ken Lee of the Bedford Institute of Oceanography in Nova Scotia, Canada.
So could bugs help cleanse the gulf? A number of companies have tried to create bacteria that could break down oil on demand, but Lee and colleague Albert Venosa of the Environmental Protection Agency say that experiments have shown that novel bacteria, even if they show promise in the lab, cannot compete with bacteria already living on beaches and marshes. Experiments have shown that adding nutrients like nitrogen, phosphorus, and potassium to the beaches can speed up the ability of natural bacteria to break down oil. "What would've taken 5 or 6 years to accomplish can occur in a single summer," says Lee.
While adding such fertilizers has worked in small scale coastal experiments in which oil was purposefully spread on wetlands, experts don't know of examples from an actual spill. The challenge with wetland marshes is that the toxicity of the oil can kill plants before the microbes have a chance to get to work on the oil. "If that happens, you can lose the whole marsh," Lee says. Workers have been trying to remove as much oil at sea as possible to reduce the amount that hits the shore. They will also need to deploy protective booms to protect the wetlands.
Another challenge: it appears to Vennosa, from photos and news reports, that the oil leaking from the borehole contains water. That makes it more difficult to burn at sea, more difficult to break up into tiny particles using chemicals called dispersants, and more difficult for bacteria to break down. But he cautions that he has not gotten real data on the makeup of the oil striking the coast.
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