METHANE-EATING bacteria discovered in a lake beneath Antarctica may prevent the powerful greenhouse gas from being release into the atmosphere as ice sheets melt, scientists believe.
Researchers from Aberystwyth University, Louisiana State University and Montana State University have analysed samples of water and sediment retrieved from Lake Whillans which lies 800 metres below the West Antarctic Ice Sheet.
Isolated from direct contact with the atmosphere for many thousands of years, the lake was successfully drilled by the Whillans Ice Stream Subglacial Access Research Drilling (WISSARD) project in 2013.
The team used a combination of measurements of methane concentrations and genomic analyses to describe how lake bacteria chemically convert methane in a way that reduces the warming potential of subglacial gases during ice sheet retreats.
The prevalence of methane-consuming bacteria in the upper lake sediment suggests a ‘methane bio-filter’ prevents the gas from entering the subglacial water, where it can eventually drain into the ocean and be released into the atmosphere.
The bacteria obtain energy from digesting the methane.
Their findings have been published in a paper in the journal Nature Geoscience – Microbial oxidation as a methane sink beneath the West Antarctic Ice Sheet.
