Carbon Sequestration Rates of Different Marsh Zones in the Schoodic Marsh of Acadia National Park, Maine

Sorrell, Lee

Abstract: 'Salt marshes are potential carbon sinks but marsh zones can transgress of relative sea level rise exceeds critical thresholds. This research was undertaken in the Schoodic Section of Acadia National Park, Maine, in order to determine which marsh zones have the highest carbon sequestration potential. Nine 60cm cores were taken from the Schoodic Marsh, three each from high, low, and freshwater marsh area, to use for calculation of carbon sequestration rates. Percent organic carbon was determined using an elemental analyzer. Solid bulk density was also determined and sedimentation rates were calculated based on bulk radiocarbon dates of basal core sediments. The low marsh core had the lowest percentage of organic carbon but the sequestration rate was highest due to a high sedimentation rate. The high marsh cores and the freshwater marsh cores showed similar carbon sequestration rates. The data for this marsh show that carbon storage potential is higher when low marsh overtakes high marsh and does not change significantly when a high marsh overtakes freshwater marsh. Release of methane in freshwater marsh zones could offset the additional carbon storage potential, but our Eh/pH data suggest that this process was not occurring to a significant degree in the solid that we tested.' Research Recommendations: taken from conclusion ô...All marsh zones studied appear to be functioning as carbon sinks, but direct measurement of CO2 and CH4 release from these wetlands would allow for a more complete representation of the carbon mass balance. Taking cores from other marshes in the area and along the Maine coast would show if this marshesÆ carbon sequestration rates are typical or atypical. The establishment of clay marker horizons in different marsh zones in a series of marshes in Acadia National Park would allow us to expand the dataset and more accurately measure modern carbon sequestration rates. Another way to expand this study would be to do a series of PB210 dates on several cores from each marsh zone to determine how the sedimentation rates and Carbon sequestration rates have changed over time. With these data, the carbon sequestration rates could be compared to the climatic record to see if historical carbon sequestration rate changes, if any, are linked with human-induced climate shifts.ö /STUDY LOCATIONS:/ /SCHOODIC PENINSULA/ GIS CATEGORY 2 = coordinates are provided for the nin sampling sites in the Schoodic marsh.