Intertidal oyster reef elevation restoration: using a durable substrate on Lone Cabbage Reef, Florida, United States

Introduction Oyster reef restoration has expanded in the Gulf of Mexico, yet many large‐scale projects fail to sustain ecological or physical outcomes. A key challenge is maintaining vertical relief in dynamic estuarine settings, where low elevation and cultch degradation limit recruitment and reef persistence. Objectives This study evaluates whether intertidal reef elevation can be reliably restored and maintained using locally sourced limestone in the low‐energy, open‐ocean facing environment of Suwannee Sound, Florida. We compare elevation changes across 26 constructed reef pads with pre‐construction and nearby wild reef elevations. Methods In 2018, 26 reef pads were built along 5 km of Lone Cabbage Reef. Elevations were surveyed post‐construction and in 2021 using a Real‐Time Kinematic (RTK) Global Positioning System (GPS) over 304 transects. Pad‐level summaries, linear regressions, and spatial models assessed elevation change and geographic trends. Results All reef pads met or exceeded target elevations and remained above pre‐construction levels after 3 years. Mean elevation declined approximately 0.14 m but stayed within the range of adjacent wild reefs. Regression showed modest decline and greater subsidence east and south. Conclusions The Lone Cabbage project shows reef elevation can be restored and maintained at scale using durable limestone and targeted intertidal design. Despite some settling, structures remained within ecologically functional elevation zones.