In the first ambitious journal article related to the gulf oil spill, scientists report that a huge plume of dispersed oil may not be breaking down rapidly. The data used to form their conclusion was gathered in late June.
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Undersea plumes of microscopic oil droplets extending dozens of miles from the BP wellhead may be more toxic to marine microorganisms in the Gulf of Mexico than previously believed, according to preliminary experimental results from Florida researchers.
Scientists from the University of South Florida, working from a research vessel northeast of the wellhead, found oil droplets scattered in sediment along the gulf floor and in the water column, they said in a report on Tuesday. The dispersed oil appeared to be having a toxic effect on bacteria and phytoplankton, a photosynthetic microorganism that serves as a vital food for fish and other marine life.
The findings require further tests to confirm that the toxic effects are being caused by oil and that the oil originated from BP’s well. But if the results hold true, they would add weight to warnings from independent scientists that the heavily dispersed oil in the gulf remains a persistent threat to sea life.
“It would confirm our worst fears — that the oil is dispersed but that it’s still harming the food web,” said Jeffrey Short, chief scientist for the conservation group Oceana and a former oil pollution researcher with the National Oceanic and Atmospheric Administration, who was not involved with the experiments. Read more…
In an article on Wednesday and a followup on Thursday, my colleague Leslie Kaufman and I wrote about a new government report that says that about three-quarters of the oil from the Deepwater Horizon spill has effectively been dealt with through capture, skimming, burning, dispersion or dissolution. The implication is that the oil poses little additional risk to shorelines or at the ocean’s surface.
Further damage in the deep sea from undersea plumes of dispersed oil cannot be entirely ruled out, government scientists said in releasing the report, but testing has shown that the hydrocarbon levels in those plumes are exceedingly low. Many toxicologists consider additional damage from the plumes to be unlikely.
The report estimated that about 8 percent of the oil that spewed from BP’s well was dispersed by using chemicals, and that once again raises an issue that has been a focus of intense public concern.
Could the dispersants themselves pose a risk to marine life, or to human health if they accumulate in seafood? Read more…
Scientists from Texas A&M and the University of California, Santa Barbara, will try to measure the size of the gulf oil spill more precisely by taking continuous measurements of methane with machines that can also fingerprint deep-water oil plumes to track their dispersal.
“What’s coming out of the spill currently is 40 percent methane by weight,” Dr. John Kessler, an assistant professor of oceanography at Texas A&M, said in an interview. “We’ll be measuring methane in the water and the atmosphere every 10 seconds, which will gives us an unprecedented amount of data.”
After sailing to Gulfport, Miss., on their research vessel, the Cape Hatteras, Dr. Kessler’s team and a group of researchers from the University of California, Santa Barbara, are scheduled to set out on Saturday to conduct measurements. The voyage is being financed by a $160,000 grant from the National Science Foundation.
Other expeditions, including one led by Samantha Joye of the University of Georgia, have been measuring the extent of the oil spill and taking methane measurements. The difference in Texas A&M’s approach is in technology and technique, Dr. Kessler said. Read more…
In an article in Wednesday’s Times, I wrote about a scientific voyage last summer on which marine biologists discovered one of the largest coral reefs in the northern Gulf of Mexico, 1,300 feet down on the seafloor in frigid temperatures and total darkness.
Less than two months ago, these biologists were gearing up for a return expedition to the site to take stock of their discovery. But those plans have been upended by the immense oil leak from BP’s blown-out well: as fate would have it, their discovery is just 20 miles north of the well site. Preliminary research shows what appear to be plumes of oil particles already in the reef’s direct vicinity, with layers touching the ocean floor in some areas.
Researchers fear that these plumes could wreak havoc on the reef and the multifarious sea life that live there.
The only upside to the situation may simply be that it offers scientists a rare opportunity to study exactly how a massive release of oil and chemicals a mile underwater affects deep-sea life.
Having mapped, photographed and sampled the corals on the research cruise last summer, scientists will be able to compare and contrast their health before and after the spill. And sediment traps installed on the seafloor – designed to capture the “marine snow” of algae, sediment and other organic material that drifts down through the water column and that deepwater corals feed upon – will allow them to determine if oil particles are also sinking to the bottom. Read more…
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 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. Read more…
The discovery that the oil from the Deepwater Horizon blowout may be spreading beneath the sea in plumes of fine droplets came as dismal news early this week. If that observation holds up to further scientific scrutiny, it would mean that the true dimensions of the problem are still invisible, and sea life is being exposed to a heavy load of toxins.
But the discovery, bad as it could prove to be for the ocean, has also created a fascinating problem for big brains of a certain kind. People who spend their time thinking about subjects like fluid dynamics, and turbulent plumes, and supercritical fluids, have gone into overdrive trying to figure out what might be going on a mile beneath the surface of the ocean.
The usual expectation is that oil of any kind floats on water. But anybody who has ever shaken a vinegar-and-oil salad dressing knows it is not quite so simple. In the right conditions, oil droplets can get suspended in water. What’s happening in the Gulf of Mexico right now might turn out to be the mother of all salad dressings.
The situation is not entirely unexpected. Scientists have predicted for more than a decade that a deepwater blowout – this one is a mile beneath the waves — would produce strange behavior, probably including plumes of oil that would not rise quickly to the surface. A test off the coast of Norway in 2000 supported by the American government and the oil industry confirmed the effect, though it was far smaller than the Deepwater Horizon blowout. Read more…