Interpreting sea level rise and rates of vertical marsh accretion in a southern New England tidal salt marsh

Abstract

An investigation of marsh accretion rates on a New England type high marsh (Barn Island Wildlife Management Area, Stonington, Connecticut) reveals that this system is sensitive to changes in sea level and storm activity and the peat can accurately record rates of relative submergence as determined by tide gauge records over intervals of 2-5 decades. The results also suggest that the relationship between the accretion deficit and plant community structure is important when utilizing peat records to reconstruct historic sea-level curves within stable Spartina patens high marsh communities. In systems where major vegetation changes are prominent over short periods of time (< 50 years), interpretations of sea-level rise should be limited to the system in which they are developed unless careful vertical controls can be maintained on the data and multiple datable horizons can be identified within the substrate. The results of this investigation further show that in a stable Spartina patens community within this particular system there is little vertical translocation of 137Cs, making this isotope a powerful tool for assessing rates of vertical marsh development since 1954.