Thursday, June 7, 2007 - 8:15 AM
349

Methanogenesis and methane oxidation in Arctic Lake Sediments

John Hart-Smith1, Dendy Lofton, MS2, Robert Northington, MS1, Ken Fortino, MS2, Steve Whalen, PHD2, and Anne Hershey, PHD1. (1) Biology, University of North Carolina Greensboro, 312 Eberhart Building, Greensboro, NC 27402, (2) Department of Environmental Science Engineering, University of North Carolina, Chapel Hill, NC 27514

            Methanogenic bacteria in lakes may represent a significant source of methane to

 the atmosphere, and methane oxidation provides a mechanism for incorporation of

 methane-derived carbon into food webs. In this study, methane production and

 oxidation in sediments of ten arctic lakes was experimentally assessed and compared to

 the physical characteristics of the lakes. Intact sediment cores were treated with methyl

 fluoride, a specific inhibitor of methane oxidation, or left untreated(controls), and

 methane flux was assessed over a 24 hour period using gas chromatography. Methane

 production ranged from ­76.79 micromoles/m2/day  to 7750.35 micromoles/m2/day.

 Percent oxidation ranged from 20.14% to 100%. Dissolved oxygen was negatively

 correlated with methane production. These results show that methane production is

 important in arctic lake sediments. The high rate of methane oxidation is consistent with

 previous studies that indicate an important role for methane-derived carbon in benthic

 food webs and that this role varies with dissolved oxygen. Further studies are needed to

 fully understand the physical controls on methane production.


See more of Lentic Ecology
See more of Contributed Sessions

See more of The NABS 55th Annual Meeting