Abstracts

Presented by Madelyn McFarland - Email: mbm391@msstate.edu

"Marsh terracing is a restoration technique that uses in situ sediment to construct segmented ridges in open water areas of coastal wetlands. Marsh terraces are constructed primarily to: 1) reduce wave fetch and associated wave energy; 2) mitigate for marsh erosion; 3) promote growth of submerged aquatic vegetation; 4) create emergent marsh, and; 5) improve marsh conditions and habitat for various wildlife species. Over 81 projects that have constructed >980 km linear feet of terrace in coastal Texas and Louisiana have occurred since 1990. Despite terraces being a potentially viable coastal restoration technique, long-term efficacy of terraces has not been studied. Our project is comprised of a multi-disciplinary team that is using modeling, and field and remote sensing techniques to study winds, waves, sediment transport, shoreline change, submerged aquatic vegetation, and avian species habitat use across multiple marsh terrace sites in coastal Louisiana. Wintering waterfowl and secretive marsh bird surveys were conducted to compare avian habitat use in terraced fields, control sites (unterraced fields), and reference marshes (intact marsh). Although preliminary, results for some of these surveys include: 1) Terraced fields were used predominantly by non-focal species such as red-winged blackbirds; 2) there was generally low use of terraced fields by focal species such as rails; 3) there was generally low use of both terraced and control sites by wintering waterfowl, although species abundances varied spatially and temporally; 4) and vegetation surveys suggest a correlation between vegetation type and structure and avian species use of terraced fields. Ongoing monitoring efforts of submerged aquatic vegetation, emergent marsh loss and gain, and wind and wave modeling will provide further insight into these preliminary results.