SHORELINE STABILIZATION POTENTIAL OF RESTORED OYSTER REEFS IN GALVESTON BAY, TEXAS

Coastal wetlands provide many services for the areas that surround them including structured habitat, water filtration through the sediment, and dissipation of storm effects. Increasing rates of wetland loss are cause for concern in many coastal communities and habitats. There have been increased efforts to restore and protect coastal wetlands using living shoreline structures such as oyster reefs. One common method to first protect, and then facilitate wetland restorations, is to construct oyster reefs that can stabilize the shoreline. Oyster reefs (Crassostrea virginica) are valuable options for living shoreline structures because they have been measured to have vertical growth rates that can match or exceed current projections of sea-level rise. The objective of this study was to quantify the effects of restored intertidal oyster reefs on tidal flat sedimentation in the West Bay of Galveston Island. Sediment pins made of 7-ft-long PVC pipe were buried to a depth of 3 ft and an initial measurement of the elevation at the top was made to establish a baseline. These sediment pins were deployed at a restored oyster reef (n=6), and at a reference site (n=6), which lacks any restored reefs. Subsequent measurements of the sediment pin elevation were collected weekly between February-September 2018, and provide a proxy for the net sedimentation in the area. The site with the restored reefs experienced an overall trend of deposition, average of 0.5 mm, while the site lacking oyster reefs experienced net erosion, average of 0.4 mm. The results of this study may be utilized to direct management decisions for future restoration efforts of oyster reefs which could be used to mitigate erosion and other effects related to sea level rise and protect coastal communities as well as make decisions regarding future projects as well as assist in acquiring funding to continue existing projects.