To: Road Walker who wrote (20927 ) 6/2/2010 10:59:32 AM From: Eric Respond to of 86355 Evidence of Undersea Oil Plumes Tony Hayward, the chief executive of BP, claimed recently that his company’s testing has shown “no evidence” that any of the oil in the Gulf of Mexico is lurking beneath the ocean surface. Oil is lighter than water, Mr. Hayward explained, and will rise to the top. Apparently Mr. Hayward is not familiar with the results of a test conducted in Norway, in which his company took part, that suggested exactly the opposite would happen when oil was released in very deep water. A demand has come from Congress that Mr. Hayward explain himself. In the meantime, university researchers keep adding to the preliminary body of evidence suggesting that some of the oil — no one knows what proportion — is dissolving into the water and forming huge plumes of dispersed oil droplets beneath the surface. This is worrisome because it raises the possibility that sea life, including commercially important species of fish, could be exposed to a greater load of toxins than conventional models of oil spills would suggest. At least three groups of researchers have now reported evidence for these undersea plumes of oil droplets. And the government, with little fanfare, posted a map this week showing the location of one plume, based on sampling done by a research ship operating under contract to BP. This would seem to be the most detailed confirmation yet by a federal agency that the undersea plumes are real. The first group to report the subsea plumes was led by Samantha Joye of the University of Georgia and Vernon Asper of the University of Southern Mississippi, who found several apparent plumes at various ocean depths, generally stretching west or southwest from the gushing oil well. Their team has spent much of the past few weeks in the gulf aboard two different ships, trying to map the plumes, which appear to shift with undersea currents. The Joye-Asper team is back out this week under a grant from the National Science Foundation. Their report was followed last week by an announcement from researchers at the University of South Florida who found a similar plume stretching northeast of the leaking well, toward Mobile Bay. And a group at Louisiana State University has also reported finding similar indications of oil hovering below the surface. All of this work is preliminary, and neither the government nor university researchers have released definitive chemical analyses that would show what is in the deep water. Lately researchers have begun pulling up samples from within the plumes that display a visible sheen and the smell of hydrocarbons. But the main evidence still consists of unusual readings taken with instruments that are lowered by cable from ships to the ocean floor. Passing through a suspected plume, these instruments show huge spikes in a reading known to oceanographers as C.D.O.M., for colored dissolved organic matter. Dissolved oil can produce such spikes. It is not the only substance capable of doing so, but the others are rarely found in quantity in the deep ocean. The C.D.O.M. spikes in the suspected plumes are associated with other anomalies, including a high reading on an instrument that essentially measures the murkiness of seawater. Dr. Joye explains more of the technical details in a blog she is writing, and she has posted an example of what the spikes look like. In most water samples coming up from the deep, the level of dissolved oil (assuming that’s what it is) is low and usually cannot be seen with the naked eye. But that’s not always the case; take a look at the pictures above. These are from Dr. Joye’s group, which identified a plume earlier this week that appears to be denser than most of the others. The experiment was done by a young University of Georgia researcher named Adam Rivers. The filter shown at left is essentially a control; it was photographed after nearly three gallons of clean water from a part of the ocean above the plume was passed through it. The filter at right was photographed after a similar volume of water from the plume was passed through. It is visibly oily. What will turn up in chemical analyses of the water from these suspected plumes? Various academic groups are racing against one another to complete such tests, while also worrying about whether scientific journals will try to block their papers if they release the results early, as the public interest would seem to warrant. The government and BP are conducting similar tests, and as noted above, the Environmental Protection Agency has begun to make public some useful information. But the test results released so far are still incomplete. The big question remains: Exactly which toxins are dissolving into the ocean, and how high are the levels?green.blogs.nytimes.com