Department or Program

Geology

Abstract

This study focuses on seasonal methane emissions in four different salt marshes in southeastern Maine. Each site is located in a brackish salinity regime and contains similar vegetation (Typha latifolifa, and Typha angustafolia). The aims of this study were twofold 1.) to test the efficacy of using Typha as a proxy for determining seasonal methane emissions and 2.) to determine what degree methane emissions in regions of Typha differ across marshes in close proximity within the same season. The project used static gas chambers to sample CH4 emissions in four different marshes from May 2016 to September 2016. The methane emissions were measured using a gas chromatograph and flame ionization detector (GC-FID). The study found similar temporal methane fluxes across three of the four marshes and found the average flux of methane over the sampling season to be 12.74 +/- 8.0 umol/(m2*hr) for those three marshes. A notable exception was Little River Marsh, which had higher CH4 fluxes ranging up to 188.0 umol/(m2*hr). It is concluded that the driving difference in the Little River Marsh methane flux in comparison with the other marshes, was resultant from the differing water tables of the regions. Additionally, when comparing the fluxes of 2016 with research done on the same sites in 2015 a 6x decrease in methane emissions were observed. It is interpreted this was also resultant from the difference in the water table as well, as the 2016 season was experiencing a drought and received half of the precipitation over the monitoring season as that of 2015.

Level of Access

Restricted: Embargoed [Bates Community After Expiration]

First Advisor

Beverly Johnson

Date of Graduation

5-2017

Degree Name

Bachelor of Science

Number of Pages

70

Download

Embargoed

Available to Bates Community via local IP address or Bates login on Tuesday, January 27, 2026.

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