First-Year Performance of the Pervious Oyster Shell Habitat (POSH) along Two Energetic Shorelines in Northeast Florida

Novel living shoreline methods are being developed to minimize negative environmental impact while maintaining strength and effectiveness in high-energy systems. The “Pervious Oyster Shell Habitat” (POSH) is a novel structure composed of oyster shells bound by a thin layer of Portland cement into the shape of a dome. The structure’s makeup greatly reduces its environmental impact while providing optimal substrate for the provision of oyster reef habitat. Previous laboratory testing has demonstrated that the structure is robust, and this follow-up study assesses the structure’s performance in the estuarine environment. Oyster and barnacle densities were compared between POSH modules and the industry standard “Oyster Ball” model Reef BallTM along two energetic shorelines in northeast Florida. Oyster densities on the POSH were high and significantly greater than on the Oyster Ball at both sites. Barnacle densities did not differ between structures and did not appear to affect oyster recruitment. The size distribution of oysters on POSH and Oyster Ball modules was measured to assess the demographics and growth of oysters over time. Overall, demographics were similar among the two structures. Differences in oyster densities and demographics were greater at our more energetic site. Results show that the POSH can be an optimal structure for early oyster recruitment and reef development in energetic systems and should be considered by restoration stakeholders.