Biological Sciences, Earth Sciences
Rising seas are threatening coastal communities and putting added pressures on the natural environment. Sea level rise rates are increasing on a global scale (from 1.7 to 3.2 mm/yr). Salt marshes are not only intertidal habitats acutely influenced by sea levels, but they also provide key ecosystem services such as: buffers against storm surges, habitat for wildlife, carbon dioxide storage, and pollutant filtration. In New England, salt marshes have built at a rate of 1 to 2 mm annually over the past 4,000 years, which has kept pace with sea level rise. However, we do not know if salt marshes can keep building if sea levels rise at a more rapid rate of 4 mm/yr or greater. To monitor how salt marshes are responding to faster sea level rise, we measured salt marsh accretion and elevation change along the coast of New Hampshire at three different marshes (a total of 11 stations) using marker horizons and a Surface Elevation Table (SET). The SET sites were established in two marshes over a decade ago and more recently at a third marsh in 2011. Data were collected in 2013 and the new rates are compared to previous elevation changes. The major findings included an unprecedented marsh elevation growth rate of 4.3 mm/yr, which shows that our marshes are building at rates fast enough to keep up with the current sea level rise. Furthermore, the rate of salt marsh building appears to be greater than the global sea level rate of 3.2 mm/yr, suggesting our local rate of sea level rise may be greater than 3.2mm/year. Salt marshes could provide a valuable indirect measure of local sea level rise.
Date of Publication or Presentation
Undergraduate Research Project
College or School
Tierney, Sarah Martina, "Salt Marsh Values in a Changing World: Examining Sea Level Rise on Tidal Marshes with a Surface Elevation Table" (2014). Student Research Projects. 11.
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