Abstract
Marine debris discarded in or transported onto marshes can negatively impact vegetation and shoreline stability. Such loss of habitat is of concern to coastal areas in the northern Gulf of Mexico due to ongoing habitat degradation and erosion as well as receding shorelines resulting from sea-level rise. This study aims to quantify the loss of vegetation due to the presence of debris for variable intervals of time as well as the recovery rates with and without restoration efforts after the removal of debris. Approximately 0.5 m^2 plots in Grand Bay, MS will be covered using two common types of debris items (wire crab pots and dense plastic squares intended to mimic opaque debris) for varying periods of time at both shoreline and higher marsh locations. Monthly measurements of vegetation density, vegetation shoot height, elevation profile, sediment grain size, and spatial extent of impact of the item will be collected to assess changes in marsh dynamics. After each sequential time period, debris from a subset of plots will be removed. Following removal, half of the plots will be re-planted, while the rest will be left to recover without intervention. Recovery will be measured by the same parameters as when the debris was present. At the conclusion, all plots that have not naturally recovered will be re-planted to minimize any negative impacts of the study. Data from this project will provide useful spatial and temporal information for making critical decisions when prioritizing the urgency and location of wetland cleanup sites from ongoing litter accumulation and sudden debris spreading disturbances such as in the aftermath of hurricanes.
