Bacteria bloom digests massive quantities of gas
By Summit Voice
SUMMIT COUNTY — After collecting thousands of water samples across 36,000 square miles in the Gulf of Mexico, university researchers last week said methane levels have returned to near normal just a few months after the massive blowout of BP’s oil well.
Back in mid-June, during the spill, the same team found methane concentrations up to 100,000 times above normal levels, but after the recent sampling, they concluded that massive bacterial blooms have consumed the immense gas plumes, estimated at more than 200,000 metric tons of dissolved methane.
The scientists were surprised by their findings.
“What we observed in June was a horizon of deep water laden with methane and other hydrocarbon gases,” said UCSB oceanographer David Valentine. “When we returned in September and October and tracked these waters, we found the gases were gone. In their place were residual methane-eating bacteria, and a 1 million ton deficit in dissolved oxygen that we attribute to respiration of methane by these bacteria.”
The findings of the study were published this week in Science Xpress, in advance of their publication in the journal Science.
“Based on our measurements from earlier in the summer and previous other measurements of methane respiration rates around the world, it appeared that (Deepwater Horizon) methane would be present in the Gulf for years to come,” said Texas A&M oceanographer John Kessler. Instead, the methane respiration rates increased to levels higher than have ever been recorded, ultimately consuming it and prohibiting its release to the atmosphere.”
While the scientists’ research documents the changing conditions of the Gulf waters, it also sheds some light on how the planet functions naturally.
“This tragedy enabled an impossible experiment,” Valentine said, “one that allowed us to track the fate of a massive methane release in the deep ocean, as has occurred naturally throughout Earth’s history.”
“We were glad to have the opportunity to lend our expertise to study this oil spill,” Kessler said. “But also we tried to make a little good come from this disaster and use it to learn something about how the planet functions naturally. The seafloor stores large quantities of methane, a potent greenhouse gas, which has been suspected to be released naturally, modulating global climate. What the Deepwater Horizon incident has taught us is that releases of methane with similar characteristics will not have the capacity to influence climate.”
The Deepwater Horizon offshore drilling platform exploded on April 20, 2010, about 40 miles off the Louisiana coast. The blast killed 11 workers and injured 17 others. Oil was gushing from the site at the rate of 62,000 barrels per day, eventually spilling an estimated 170 million gallons of oil into the Gulf. The leak was capped on July 15, and the well was permanently sealed on Sept. 19.
The work was funded by the National Oceanic and Atmospheric Administration (NOAA) through a contract with Consolidated Safety Services Inc., the Department of Energy, and the National Science Foundation. Other members of the research team from UCSB include postdoctoral researcher Molly Redmond; graduate students Stephanie Mendes and Stephani Shusta; and undergraduate students Christie Villanueva and Lindsay Werra.
Filed under: BP Gulf oil spill, Environment, oil drilling Tagged: | BP, Deepwater Horizon, Environment, Gulf of Mexico, methane in Gulf of Mexico, National Oceanic and Atmospheric Administration, National Science Foundation, Oil spill, Summit County Colorado, Summit County News