Effects of Small-scale Armoring and Residential Development on the Salt Marsh/Upland Ecotone in Coastal Georgia, USA

Use of small-scale armoring placed near the marsh-upland interface to protect single-family homes from flooding is a widespread coastal development practice, but its effect on the environment is under studied. We compared the biota and environmental characteristics of 60 marshes on the coast of Georgia, USA, that were adjacent to either a bulkhead, a residential backyard with no armoring, or an intact forest during June-July 2013 using a nested, spatially blocked sampling design. For each plot in each sampling site, we used real-time kinematic (RTK) GPS to measure the location and elevation of the upper marsh. We collected cores to determine porewater salinity and nutrient concentrations as well as grain size distribution of marsh sediments. We quantified flora (vegetation composition) and fauna (snail, bivalve, and crab abundance) in the upper marsh ecotone. For sites with bulkheads, we recorded the height, thickness and condition of the bulkhead, as well as surveyed the animals living on and around the bulkheads.