Southeastern Section - 64th Annual Meeting (19–20 March 2015)

Paper No. 12
Presentation Time: 1:00 PM-5:00 PM


MORRIS, Claire Elizabeth, SHOWALTER, Shane Lucas and WHITMEYER, Shelley J., Geology and Environmental Science, James Madison University, 395 S. High Street, MSC 6903, Harrisonburg, VA 22807,

Tidal marshes are a vital part of the coastal system. They buffer the mainland, provide habitat for organisms, and remove excess nutrients from water. Marsh elevation is closely correlated to relative sea level. Today, accelerated rates of sea level rise threaten our marshes. To adapt to higher sea levels, marshes must vertically accrete at a rate approximately equal to sea level rise. Bluff Point is a tidal marsh located on the western side of the Chesapeake Bay in Northumberland County, VA. This is an excellent place to study the affect of sea level rise on marshes because the region is experiencing accelerated sea level rise. According to the International Panel on Climate Change 5thAssesment (2013) eustatic sea level rises at a rate of 2.0 mm/yr from 1971-2010, whereas relative sea level rise at Bluff Point is 5.5 mm/yr (NOAA Lewisetta, VA tide gauge, 1974-2013).

This research determined the relative contribution of organic and inorganic material to marsh accretion. Loss-on-ignition was used to determine spatial patterns of organic contributions to the marsh. The loss-on-ignition from the top 10 cm of the marsh ranges from 4.2% to 7.4%. Results show that the percent of organics increase with distance from tidal creeks or beaches, and the percent of organics decrease with depth. Results of loss-on-ignition were also compared to decomposition with Hydrogen Peroxide as another proxy for organic material. This analysis is the first step in understanding the importance of organic material with respect to marsh evolution.