Bacteria hitchhike on methane bubbles, keep greenhouses gas in check
Seafloor-dwelling bacteria may hitch a ride on methane bubbles seeping from deep-sea vents, preventing the methane from reaching the atmosphere by eating it up, new research suggests.
The findings, presented here on Dec. 9 at the annual meeting of the American Geophysical Union, could help explain how such huge amounts of the greenhouse gas methane are belched from the ocean floor, yet somehow never reach the atmosphere.
“Above these methane seeps, you have these bubbles released from the sediment and you can see a higher abundance of these microbes in the water column,” said study co-author Oliver Schmale, a geologist and marine chemist at the Leibniz Institute for Baltic Sea Research in Germany. “The microbes consume methane from these seeps before it escapes into the atmosphere.”
Methane is a potent greenhouse gas, and huge reserves of it are buried beneath the oceans. Many scientists worry that if the oceans warm enough, these huge troves of methane could be released from their deep-sea storage and released into the atmosphere, fueling a huge spike in temperatures.
While much of the methane is locked in an inactive form, at shallower depths, bubbles of methane naturally seep up from mud volcanoes and other cracks in the ocean floor. Yet somehow, very little of this methane reaches the atmosphere.
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