Description/Abstract/Artist Statement
Methane (CH4) is a potent greenhouse gas partially responsible for global temperature increase. This compound is released by methane-producing organisms known as methanogens. We aimed to sample and analyze local marine methane levels to track changes over time during a King Tide flooding event to provide insights into where methane is enriched in local urban waterways. We collected water from 10 sites in a 12-day time series in Chesapeake Bay tributaries in Norfolk, Virginia, and processed these samples in a gas chromatograph (GC). Methane concentrations were highly variable among stations and varied to a lesser extent over the sampling period at each station. Additionally, we analyzed a time series of samples taken from our most CH4-concentrated site to study methane's decay due to the activity of methanotrophs (methane-consuming organisms). We observed a logistic (S-shaped) decrease in methane concentration over time. The decay rate was slow initially and increased to a maximum value of 0.9 per day on day 12. While we identified strong local sources of methane in this urban estuary we also observed the efficiency of local methane-eating bacteria that rapidly diminished methane levels with time. Our results shows that the Elizabeth and Lafayette rivers are both highly variable sources and sinks of methane.
Faculty Advisor/Mentor
Alexander Bochdansky
Faculty Advisor/Mentor Department
Ocean and Earth Sciences
College Affiliation
College of Sciences
Presentation Type
Poster
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18 - Assessing Methane Concentrations in Residential Floodwaters
Methane (CH4) is a potent greenhouse gas partially responsible for global temperature increase. This compound is released by methane-producing organisms known as methanogens. We aimed to sample and analyze local marine methane levels to track changes over time during a King Tide flooding event to provide insights into where methane is enriched in local urban waterways. We collected water from 10 sites in a 12-day time series in Chesapeake Bay tributaries in Norfolk, Virginia, and processed these samples in a gas chromatograph (GC). Methane concentrations were highly variable among stations and varied to a lesser extent over the sampling period at each station. Additionally, we analyzed a time series of samples taken from our most CH4-concentrated site to study methane's decay due to the activity of methanotrophs (methane-consuming organisms). We observed a logistic (S-shaped) decrease in methane concentration over time. The decay rate was slow initially and increased to a maximum value of 0.9 per day on day 12. While we identified strong local sources of methane in this urban estuary we also observed the efficiency of local methane-eating bacteria that rapidly diminished methane levels with time. Our results shows that the Elizabeth and Lafayette rivers are both highly variable sources and sinks of methane.