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Webinar: Sediment Deficits: The Silent Killer of Salt Marshes
Tuesday, 21 February 2017, 12:00
Tuesday, February 21, 2017. 12:00 PM. Sediment Deficits: The Silent Killer of Salt Marshes. Neil K. Ganju, Research Oceanographer, USGS, Coastal and Marine Geology Program, Woods Hole Coastal and Marine Science Center. Sponsored by NOAA Star Center for Satellite Applications and Research. More information here.
Salt marshes are valued for their ecosystem services, but their vulnerability is typically assessed through individual points on the landscape. However, multi-dimensional processes such as lateral erosion can lead to rapid marsh loss though the marsh may build vertically. Marsh sediment budgets represent a spatially integrated measure of competing constructive and destructive forces: a sediment surplus may result in vertical growth and/or lateral expansion, while a sediment deficit may result in drowning and/or lateral contraction. Here we show that sediment budgets of eight microtidal marsh complexes across the U.S. Atlantic and Pacific coasts consistently scale with areal unvegetated/vegetated marsh ratios (UVVR) suggesting these metrics are broadly applicable indicators of microtidal marsh vulnerability. All sites are exhibiting a sediment deficit, with half the sites having projected lifespans of less than 350 years at current rates of sea-level rise and sediment availability. These results demonstrate that open-water conversion and sediment deficits are holistic and sensitive indicators of salt marsh vulnerability.