Posts Tagged ‘microbes’

Doomsayers confounded as Gulf of Mexico heals itself

April 10, 2013

It was touted as the greatest environmental disaster of all time when Deepwater Horizon exploded in the Gulf of Mexico killing 11 and spilling vast quantities of crude oil. But two years later in April 2012 it was clear that the Gulf was recovering much faster than expected. It was soon clear that the effect of oil eating microbes had been grossly underestimated. And now 3 years after the accident an expert in bioremediation reported  at the 245th National Meeting & Exposition of the American Chemical Society (ACS)  that “the Gulf of Mexico may have a much greater natural ability to self-clean oil spills than previously believed”.

“It shows that we may not need the kinds of heroic measures proposed after the Deepwater Horizon spill, like adding nutrients to speed up the growth of bacteria that breakdown oil, or using genetically engineered bacteria. The Gulf has a broad base of natural bacteria, and they respond to the presence of oil by multiplying quite rapidly.”

From ACS: Terry C. Hazen, Ph.D., said that conclusion has emerged from research following the 2010 Deepwater Horizon disaster, which by some estimates spilled 4.9 million barrels (210 million gallons) of oil into the Gulf of Mexico. His research team used a powerful new approach for identifying microbes in the environment to discover previously unknown bacteria, naturally present in the Gulf water, that consume and break down crude oil.

“The Deepwater Horizon oil provided a new source of nutrients in the deepest waters,” explained Hazen, who is with the University of Tennessee in Knoxville. “With more food present in the water, there was a population explosion among those bacteria already adapted to using oil as a food source. It was surprising how fast they consumed the oil. In some locations, it took only one day for them to reduce a gallon of oil to a half gallon. In others, the half-life for a given quantity of spilled oil was 6 days. This data suggests that a great potential for intrinsic bioremediation of oil plumes exists in the deep sea and other environs in the Gulf of Mexico.” 

Hazen spoke at a symposium, “Environmental Fate of Petroleum Oils and Dispersants in the Marine Environment,” that included other reports relating to the Deepwater Horizon spill. They were among 12,000 reports being presented at the ACS meeting, which continues through Thursday. Abstracts of the oil spill symposium appear at the end of this press release.

Oil-eating bacteria are natural inhabitants of the Gulf because of the constant supply of food. Scientists know that there are more than 600 different areas where oil oozes from rocks underlying the Gulf of Mexico. These oil seeps, much like underwater springs, release 560,000-1.4 million barrels of oil annually, according to the National Research Council.

Hazen’s team used a powerful new approach for identifying previously recognized kinds of oil-eating bacteria that contributed to the natural clean-up of the Deepwater Horizon spill. In the past, scientists identified microbes by putting samples of water into laboratory culture dishes, waiting for microbes to grow and then using a microscope to identify the microbes. The new approach, called “ecogenomics,” uses genetic and other analyses of the DNA, proteins and other footprints of bacteria to provide a more detailed picture of microbial life in the water.

“The bottom line from this research may be that the Gulf of Mexico is more resilient and better able to recover from oil spills than anyone thought,” Hazen said. “It shows that we may not need the kinds of heroic measures proposed after the Deepwater Horizon spill, like adding nutrients to speed up the growth of bacteria that breakdown oil, or using genetically engineered bacteria. The Gulf has a broad base of natural bacteria, and they respond to the presence of oil by multiplying quite rapidly.”

 

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Posted in Alarmism, Environment, Oil, US | 1 Comment »

Methane from BP oil spill has vanished – presumed digested by microbes

January 9, 2011
Molecule of methane.

methane molecule: Image via Wikipedia

A new paper online in Science:

Science DOI: 10.1126/science.1199697 A Persistent Oxygen Anomaly Reveals the Fate of Spilled Methane in the Deep Gulf of Mexico, by John D. Kessler, David L. Valentine, Molly C. Redmond, Mengran Du, Eric W. Chan, Stephanie D. Mendes, Erik W. Quiroz, Christie J. Villanueva, Stephani S. Shusta, Lindsay M. Werra, Shari A. Yvon-Lewis and Thomas C. Weber

It adds to the growing body of evidence that the oceans with the help of microbes are much more resilient than they have been assumed to be.

https://ktwop.wordpress.com/2010/09/12/microbes-ate-the-bp-oil-plume/

https://ktwop.wordpress.com/2010/10/20/microbes-consume-methane-10-to-100-times-faster-than-thought/

As Science News puts it:

Methane, the predominant hydrocarbon produced by the BP blowout last year, has all but vanished from Gulf of Mexico waters, a new study reports — presumably eaten up by marine bacteria. That hadn’t been expected to happen for years.

Two-thirds of the hydrocarbons released by the BP accident were forms of natural gas: largely methane, ethane and propane. While Gulf microbes quickly began devouring the larger gas molecules, they initially left tiny methane — which accounted for an estimated 87.5 percent of the gas initially emitted — largely untouched.

Some of the authors of the new paper had reported in the Oct. 8Science finding almost no microbial breakdown of BP methane in June, about a month and a half into the 83-day gusher.

Rates of biodegradation in subsea plumes, where this gas had been accumulating, “indicated methane would persist for many, many years, if not almost a decade,” observes John Kessler, a chemical oceanographer at Texas A&M University in College Station and an author of that earlier report.

To begin quantifying just how slowly that breakdown was proceeding, he and his colleagues returned to the Gulf for three research cruises between August 18 and October 4. Their sampling at more than 200 sites turned up no BP methane. In fact, concentrations of the gas in seawater throughout the spill zone were lower than typical background concentrations for the Gulf, these researchers report online January 6 in Science.

“We were caught off guard,” Kessler says. “But that highlights the beauty of the scientific process. You put together hypotheses based on the information at hand and test them. And whether we’re right or wrong, at the end of the day we’ll have learned something new about the system.”

The new paper’s conclusions “are quite consistent with what we’ve seen,” says microbial ecologist Terry Hazen of Lawrence Berkeley National Laboratory in California. On August 24, his team was the first to report online in Science that BP oil plumes had disappeared.

 

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Microbes consume methane 10 to 100 times faster than thought

October 20, 2010

 

Structure of the methane molecule: the simples...

methane: Image via Wikipedia

 

A follow up to my previous post:

https://ktwop.wordpress.com/2010/09/12/microbes-ate-the-bp-oil-plume/

From EurekAlert:

Microbes may consume far more oil-spill waste than earlier thought

Microbes living at the bottom of the Gulf of Mexico may consume far more of the gaseous waste from the Deepwater Horizon oil spill than previously thought, according to research carried out within 100 miles of the spill site.

A paper on that research, conducted before the Deepwater Horizon rig exploded six months ago today, will appear in a forthcoming issue of the journal Deep-Sea Research II. It describes the anaerobic oxidation of methane, a key component of the Gulf oil spill, by microbes living in seafloor brine pools.

“Because of the ample oil and gas reserves under the Gulf of Mexico, slow seepage is a natural part of the ecosystem,” says Peter R. Girguis, associate professor of organismic and evolutionary biology at Harvard University. “Entire communities have arisen on the seafloor that depend on these seeps. Our analysis shows that within these communities, some microbes consume methane 10 to 100 times faster than we’ve previously realized.”

Girguis is quick to note that methane is just part of what spilled from the ruptured Deepwater Horizon well for three months earlier this year, and that the rate at which methane spewed from the damaged well far exceeds the flow that microbes would ordinarily encounter in the Gulf.

Key to the work by Girguis, Harvard research scientist Scott D. Wankel, and their colleagues was the ability to use on-site mass spectrometry to obtain direct, accurate measurements of seafloor methane. It’s been difficult to make such measurements because most tools don’t work accurately 5,000 to 7,000 feet below the surface, where pressures can reach roughly 220 atmospheres.

Using this new technique, the scientists were able to ascertain methane concentrations in brine pools surrounding gas seeps at the bottom of the Gulf — which were extremely high — as well as in the water column above the pools. Combining this data with measurements of microbial activity, they were able to extrapolate just how quickly the microbes were consuming the methane.

“In fact, we observed oxidation of methane by these microbes at the highest rates ever recorded in seawater,” Girguis says.

Methane is a greenhouse gas, up to 60 times more potent than carbon dioxide. Gigatons of the volatile gas are produced in seafloor sediments, above and beyond that generated by gas seeps that pockmark the floor of the Gulf of Mexico and other bodies of water. But, Girguis says, somewhere between the seafloor and the sea’s surface, much of the methane vanishes.

“We found that concentrations of methane in brine pools are tremendously high: five to six orders of magnitude higher than in the water column above,” Girguis says. “Mass spectrometry has given us a window on both the amount of methane diffusing into the water column and how much of this methane is consumed through anaerobic oxidation by microbes within the brine pool. It appears the microbes consume much of the methane, and the rest dissipates over time into the water column.”

A study published in the journal Science in August detailed a bacterial species reportedly able to degrade oil anaerobically in the Gulf. But a subsequent Science paper contended that these microbes mainly digested gases like methane, propane, ethane, and butane, not oil. The Deep-Sea Research II paper adds to scientists’ growing understanding of these species’ ability to degrade the byproducts of the Deepwater Horizon spill.

Girguis and Wankel’s co-authors are Samantha B. Joye and Vladimir A. Samarkin of the University of Georgia, Sunita R. Shah of the U.S. Naval Research Laboratory, Gernot Friederich of the Monterey Bay Aquarium Research Institute, and John Melas-Kyriazi of Stanford University.

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BP Oil Plume was only 1/3 oil, 2/3 was gas

September 17, 2010
Gas from the damaged Deepwater Horizon wellhea...

Image via Wikipedia

Perhaps this helps to explain where all the oil went.

The plumes of oil that spewed into the Gulf of Mexico’s depths this spring and summer in the aftermath of the BP Deepwater Horizon blowout were actually only about one-third oil,  with the remainder consisting of natural gas.

Research reported online September 16 in Science found that in June, marine microbes were primarily feeding on propane and ethane in the oil plumes. “We estimate that there’s about two times as much gas sitting in those subsurface plumes as there is oil — and there’s about a million barrels of oil in them,” says David Valentine of the University of California, Santa Barbara, speaking by phone from a National Oceanic and Atmospheric Administrationresearch vessel in the Gulf. Chemists had been trying to estimate how much oxygen might disappear as microbes began degrading BP’s spilled oil. It now turns out oil is only a tiny part of the issue. “Probably 66 to 75 percent of the oxygen loss — maybe even a bit more — will ultimately come from bacterial metabolism of the gases,” Valentine projects.

https://ktwop.wordpress.com/2010/09/12/microbes-ate-the-bp-oil-plume/

The new research “is quite solid and something people will be taking seriously,” says Benjamin Van Mooy, a chemical oceanographer at the Woods Hole Oceanographic Institution in Massachusetts.

Terry Hazen of Lawrence Berkeley National Laboratory in California and his colleagues recently reported finding substantial microbial degradation of a particular fraction of the spilled oil called n-alkanes in subsea plumes. He says that the work by the Woods Hole team and the authors of the new Science paper doesn’t contradict his group’s findings. “They’re all quite consistent,” he says. Each group looked at different hydrocarbons at different times, and sometimes in different plumes. The environment is dynamic, he notes, and truly understanding what’s happening will take a lot more work.

One big concern since the initial discovery of deep-sea hydrocarbon plumes has been what will happen to oxygen concentrations near the seabed. Some scientists have questioned whether fish-suffocating dead zones might develop. But a September 7 federal study looked for evidence of such oxygen deprivation in plume zones and found none.

Based on four months of sampling data through August 9, “Oxygen levels have dropped by about 20 percent from their long-term average in this area of the Gulf,” said Steve Murawski, chief science advisor to NOAA’s Fisheries Department and head of the largely federal interagency Joint Analysis Group on the BP spill. Oxygen levels in plume zones have stabilized, he said, and “would have to decrease another 70 percent in order to be classified a dead zone.”

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