R-06-02 Are Maine’s marshes drowning? Determining the life cycle of salt marsh pannes

Salt marshes provide protected nursery sites for fish, crustaceans, and other invertebrates, as well as open water and food for birds. Concerned that an observed increase in pannes (shallow depressions) and pools on marshes indicates that the marshes are drowning from the inside out, as sediment accumulation fails to keep up with sea-level rise, researcher Dan Belknap and graduate student Kristin Wilson studied historic aerial photographs, maps, and sediment cores of five marshes along the Maine coast to determine how marshes change over time. They discovered that salt marsh surfaces are dynamic, with pools forming, changing size and shape, draining and re-colonizing on decadal to centennial time frames. The salt marshes they studied are able to accumulate at rates greater than six mm/year, suggesting that marshes will survive under even moderately high projections of future sea-level rise.

2-year project, 2006-2008
Total: $163,886

Related publications

Wilson, K.R., J.T. Kelley, A. Croitoru, M. Dionne, D.F. Belknap, and R. Steneck. 2009. Stratigraphic and ecophysical characterizations of salt pools: dynamic landforms of the Webhannet salt marsh, Wells, ME, USA. Estuaries and Coasts 32:855-870.

Wilson, K.R., J.T. Kelley, B.R. Tanner, and D.F. Belknap. 2010. Probing the origins and stratigraphic signature of salt pools from north-temperate marshes in Maine, USA. Journal of Coastal Research 26:1007-1026.