Paper Type

Master's Thesis


College of Arts and Sciences

Degree Name

Master of Science in Biology (MS)



NACO controlled Corporate Body

University of North Florida. Department of Biology

First Advisor

Dr. Kelly J. Smith

Second Advisor

Dr. Nicole P. Dix

Third Advisor

Dr. Eric G. Johnson

Department Chair

Dr. Cliff Ross

College Dean

Kaveri Subrahmanyam


A dramatic global decline in oyster reef habitat has led to widespread deployment of oyster restoration projects. Efforts are underway to move away from polluting methods like plastic mesh bags in oyster deployments. Additionally, increasing pressure on our estuaries from recreational boat wakes and intensified storms requires more robust structures for shoreline protection. The “Pervious Oyster Shell Habitat” (POSH) is a novel artificial reef structure composed of oyster shell 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 quality substrate for provision of oyster reef habitat in high-energy systems. Laboratory testing of mechanical strength has demonstrated that the structure is robust, and this is the first field study assessing the structure’s performance in the estuarine environment. POSH structures were assessed in-situ for oyster recruitment and utilization by fish and crustaceans. The POSH was compared to the industry standard “Oyster Ball” model Reef BallTM, from June 2021 to June 2023, along two energetic shorelines in northeast Florida, Kingsley Plantation along the Fort George River (Duval County) and Wright’s Landing along the Tolomato River (St. John’s County). Oyster demographics and densities were assessed on the structures throughout the first year of deployment. Oyster recruitment was significantly greater on the POSH compared to the Oyster Balls at both sites. Nekton densities and communities were assessed throughout the second year of deployment, using 2-m2 bottomless lift nets. Fish densities did not differ among treatments, but crustacean densities were often significantly greater on the POSH. Fish and crustacean communities were similar among treatments. Early findings for the POSH indicate that it can be a viable method for rapidly restoring reef communities of oysters, crustaceans, and fish.