Gulf damage assessments begin to roll in

It seems there is finally some good news coming out of the Gulf of Mexico.

After 170 days, the leaking oil well — nearly a mile under water — was finally plugged with mud. Officials say it means an end to the long spill. As BP stated in a news release:

“Pumping of heavy drilling mud into the well from vessels on the surface began at 1500 CDT on August 3, 2010 and was stopped after about eight hours of pumping. The well is now being monitored, per the agreed procedure, to ensure it remains static. Further pumping of mud may or may not be required depending on results observed during monitoring…

“A relief well remains the ultimate solution to kill and permanently cement the well. The first relief well, which started May 2, has set its final 9 7/8-inch casing. Operations on the relief wells are suspended during static kill operations. Depending upon weather conditions, mid-August is the current estimate of the most likely date by which the first relief well will intercept the Macondo well annulus, and kill and cement operations commence.”

If the spewing has indeed stopped for good, discussions about the fate of the contamination and restoration of the ecosystem have some real meaning. A report issued this morning by the National Oceanic and Atmospheric Administration starts to put the issue into perspective.

According to the report, about 25 percent of the 4.9 million gallons barrels (205 million gallons) released were removed by skimming, burning or direct recovery at the wellhead. Another 25 percent either evaporated or dissolved. Another 24 percent was dispersed as tiny droplets — either naturally or by the use of chemicals.

“The residual amount — just over one quarter (26%) — is either on or just below the surface as light sheen and weathered tar balls, has washed ashore or been collected from the shore, or is buried in sand and sediments,” the report concludes.

News reports that I read this morning — including a story by Justin Gillis of the New York Times — makes the point that the 26-percent residual is the amount that can still cause harm. Certainly, that 1.25 million barrels of “residual” oil is no small amount. But I’d like to hear more about the portion that has “dissolved,” along with the 24 percent still floating around as tiny droplets — including large “diffuse clouds” between 3,300 and 4,300 feet deep.

More studies are needed, but NOAA officials seem optimistic that the dispersed oil will biodegrade fairly rapidly.

Besides the fish, birds and mammals already killed (Fish and Wildlife Collection Report, PDF 99 kb), questions about the food web remain unanswered. Jane Lubchenco, NOAA’s top official, said one of the biggest questions is how much damage was done to the eggs and larvae of marine organisms needed to produce a new generation of sea creatures. Answers may not be clear for a year or more, she said.

On a slightly different topic, researchers reported yesterday that the Gulf’s “dead zone” is among the largest in history — stretching out 7,722 miles, slightly smaller than the state of New Jersey, according to reporter Allison Winter of Greenwire.

She quoted Nancy Rabalais, who leads the annual dead-zone survey, as saying the oil spill may or may not have contributed to the problem: “It would be difficult to link conditions seen this summer with oil from the BP spill, in either a positive or a negative way.”

Nutrients that flow down the Mississippi River from agricultural fertilizers and other sources are clearly identified as a contributor to the problem. Nitrogen, for example, triggers the growth of plankton, which die, sink and decompose. Bacteria involved in decomposition tend to suck up available oxygen.

With relation to the oil spill, bacteria will use up oxygen as they break down oil in the water column, but the effects in the Gulf of Mexico are widely disputed, as described in a story by Amanda Mascarelli in Nature News. Obviously, more studies are needed on this front.

Also this week, the Environmental Protection Agency issued a report on the toxicity of dispersants, finding that eight dispersants have similar toxicities and that “dispersant-oil mixtures are generally no more toxic to the aquatic test species than oil alone.”

As for worries that the oil will hit the Florida Keys or the East Coast, the Obama administration is now downplaying that threat. In a story today, reporter Mathew Daly of the Associated Press quoted White House Press Secretary Robert Gibbs as saying that the oil is unlikely to be picked up by the Loop Current and carried around the coast of Florida:

“I think it is fairly safe to say that because of the environmental effects of Mother Nature, the warmer waters of the Gulf and the federal response, that many of the doomsday scenarios that we talked about and repeated a lot have not and will not come to fruition.”

See NOAA’s report, which concludes, “Given current conditions, Southern Florida, the Florida Keys and the East Coast of the United States are not likely to experience any effects from the remaining oil on the surface of the Gulf.”

Doomsday or not, plenty of scientists and environmental activists remain worried, not only about the damage done to date but also about the ongoing effects of petroleum compounds on the Gulf’s rich ecosystem.

See MSNBC, Audubon, Natural Resources Defense Council, Gulf Restoration Network.

5 thoughts on “Gulf damage assessments begin to roll in

  1. The prediction that so much crude oil has been broken down by gulf waters, evaporated, recovered, or burned off and pose no danger to the Gulf fo Mexico is preposterous. BP and its contractors applied huge amounts of toxic “oil dispersants” to this ecological disaster. These dispersants’ primary function is to make the crude have less mass and sink from the surface of the water so that all appears well from the air and on the water’s surface (out of sight, out of mind). That is where the majority of this crude is now, either on the floor of the gulf or floating in “diffuse clouds” under the gulf surface. Both pose a great danger to life in, on, and around the Gulf of Mexico

  2. I want to believe the worst is over, but it seems a bit over-confident to give exact percentages in the total absence of data. Observers have been blocked by armed guards, scientists have been hired by BP under non-disclosure contracts, the FAA has prohibited flights over dead whales and birds. See The Crime of the Century: What BP and the US Government Don’t Want You to Know, Part I or Many questions still unanswered on dispersants following EPA report. Only a few non-profit groups are looking for dead animals or the missing plumes of oil/dispersant. Has it sunk to the bottom in toxic, gooey layers? Or is it still in suspension floating with the currents? Nobody knows, and almost nobody is even looking.

  3. I’m hoping that the raw data used to write NOAA’s “oil budget” will be made available to anyone who wishes to review the findings, and I’m hoping that knowledgeable scientists will help the rest of us determine the reliability of this report.

    Frankly, I was disappointed that the report was so general in its discussion. It fails to cite the names of documents from which the oil-recovery estimates were derived or let us know where we can find these documents. I also believe that a report like this should calculate the uncertainties in the data and offer a range of possible values for what happened to the oil rather than just gross percentages.

    I’m finding that many journalists are skeptical of this report, but they don’t know what to do next. If anyone has seen an outside scientific review of these findings, please let me know.

  4. Update, Aug. 18, 2010

    An ad hoc group of scientists organized by the Georgia Sea Grant Program has taken a fresh look at NOAA’s estimates of the fate of the oil spewed into the Gulf of Mexico. While it appears that the group does not have access to all of NOAA’s data, the scientists have interpreted the data in different ways.

    Charles Hopkinson, director of Georgia Sea Grant and professor of marine sciences at the University of Georgia, had this to say in a news release:

    “One major misconception is that oil that has dissolved into water is gone and, therefore, harmless. The oil is still out there, and it will likely take years to completely degrade. We are still far from a complete understanding of what its impacts are.”

    Hopkinson said his group considers oil classified as dispersed, dissolved or residual to be still present, whereas the previous report suggested that only the residual form was still around. Thus the two reports come to quite different conclusions.

    Hopkinson’s group estimated how much of the oil could have evaporated, degraded or weathered as of the date of the report. Using a range of reasonable evaporation and degradation rates, the group calculated that 70-79 percent of oil spilled into the Gulf still remains.

    The report, called “Outcome/Guidance from Georgia Sea Grant
    Program: Current Status of BP Oil Spill (PDF 432 kb),”
    can be downloaded from the Georgia Sea Grant website.

  5. Update, Aug. 20, 2010

    I read several articles yesterday about the new study in “Science,” which showed a toxic plume emanating from the blown-out oil well in the Gulf. The best look at the overall issue that I have seen was presented on PBS News Hour. Keep in mind that data in this first peer-reviewed study was collected two months ago, and it will take considerable time to understand the full extent of the problem.

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