Water Column Methanotrophy Fueled by Methane from the Hudson Canyon Seep Field, US Atlantic Margin

Tuesday, 16 December 2014
Molly C Redmond1, Eric W Chan2, Matthias Y Kellermann3, Eleanor Arrington3, David L Valentine4 and John D Kessler2, (1)University of North Carolina at Charlotte, Charlotte, NC, United States, (2)University of Rochester, Rochester, NY, United States, (3)University of California Santa Barbara, Santa Barbara, CA, United States, (4)Univ California, Santa Barbara, CA, United States
Several areas of methane seepage have recently been discovered along the US Atlantic margin, including parts of Hudson Canyon, offshore New York and New Jersey. However, little is known about the magnitude of seepage, the fate of this methane once it enters the water column, or the bacteria that may consume it. In July 2014, water column methane concentrations were measured throughout Hudson Canyon and methane oxidation tracked using a 13C-methane tracer. Samples for microbial community composition analysis were collected throughout the water column in areas with and without active seepage. 16S rRNA gene sequencing will be used to compare microbial communities from different depths, locations, and in samples with low and high methane concentrations and oxidation rates. DNA stable isotope probing experiments with 13C-labeled methane were also conducted and will be used to detect active water column methanotrophs from seep and non-seep sites. In addition, mesocosm experiments were used for high resolution measurements of methane oxidation, with samples for microbial community composition taken at several time points. 16S rRNA gene sequencing will be used to track changes in methanotrophic bacteria and the overall microbial community as methane was consumed.