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.
Tags: BP, Deepwater Horizon oil spill, Gulf of Mexico, methane, microbes, oil spill
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