| Some Effects of the Little Vermilion Bay Sediment Trapping Project Terrace Type Marsh Restoration in South Central Louisiana |
PRESENTATION
David Castellanos and Troy Barrilleaux
Louisiana Department of Natural Resources
Coastal Restoration Division
635 Cajundome Blvd., Suite 203A
P.O. Box 62027
Lafayette, LA 70596-2027
Abstract
One of the tools of coastal marsh restoration increasingly being utilized is the so called terracing technique. Despite the increasing use of earthen terrace creation as a tool of wetland restoration, little data exists that would help determine the overall success of this technique. Some documentation, including aerial photography, has shown that land can be successfully created in open water by the conventional track hoe method that uses locally dug sediments piled up nearby to an elevation above the water line. Still, questions remain about the settled elevation of the terraces, the resulting plant community, and other benefits promised by the projects. We present data from an investigation of the CWPPRA project, Little Vermilion Bay Sediment Trapping Project (TV-12). Elevation surveys, emergent vegetation and submerged aquatic vegetation (SAV) sampling provide some preliminary answers to questions such as: How much do terraces sink? What happens to deep borrow ditches? Will emergent marsh vegetation colonize created terraces? Do plantings grow well on terraces? Do terraces designed to trap sediment deliver on that promise? Will SAV become established or increase in cover? Our results provide a detailed description of which plant species colonized which elevation zones of the terraces, how different zones of the project area (i.e. terrace, channel bottom, and bay bottom among terraces) changed in elevation over time, and how much, if any benefits to SAV have resulted. |
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