New findings from the Woods Hole Oceanographic Institution based on measurements taken in June when oil was still spilling from BP's Macondo well challenge government estimates that the vast majority of the 4.9 million barrels of spilled oil is already gone from the Gulf or being rapidly broken down by bacteria. The Woods Hole scientists reported their preliminary findings online in the journal Science and concluded that some of the oil may persist deep under water—at levels thousands of times higher than those caused by the natural oil seeps that dot the Gulf sea floor. The scientists made 57,000 measurements, mainly using sensors aboard a remote-controlled robot deployed from the ship.No one knows yet how long oil plumes will last or what their long-term impact will be. Experts are concerned that if the trace chemicals linger long enough, they could damage fish eggs and larvae, as well as the plankton on which many fish feed.
For 10 days in June, the Woods Hole team was aboard a U.S. National Science Foundation research vessel exploring the plume—22 miles long and more than a mile wide—as it snaked along 3,000 feet below the surface of the Gulf. The scientists confirmed that oil from the well had been caught below the surface of the Gulf in pools of microscopic oil drops and petroleum-based trace chemicals. The plume resembled a mist of trace chemicals largely invisible to the eye, rather than a river of oil. The Woods Hole researchers found high concentrations of benzene, toluene, xylene and other so-called BTEX petroleum compounds that could be traced to the leaking well. They calculated that the plume contained between 5% and 6% of the signature BTEX petroleum hydrocarbons released during the spill. (WSJ, 8/20/2010)
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