Natural and Enhanced Coral Reef Recovery After Injury

The coral reefs of Broward County, southeast Florida, USA are located offshore a highly urbanized area. Because of the close proximity of a major shipping port and its associated anchorage, Broward reefs have been impacted by more than 10 ship groundings over the last 15 years. These injuries usually require restoration to speed recovery and compensate for damage. However, the recovery process on injured sites is not well understood, and even less is known about how restoration aids in recovery. This study examines coral recruitment, growth, and mortality in permanent quadrats on injured sites to asses their potential for natural recovery. It also investigates substrate materials commonly used in reef restoration, including limestone, concrete, and terracotta, to determine their efficacy in attracting and retaining coral recruits. Lastly, transplantation of juvenile corals collected on settlement plates from areas of higher coral recruitment and of corals raised in the lab from the larval stage is examined as a potential method to enhance reef restoration. Preliminary results indicate coral recruitment rates to injured sites were higher compared to reference sites. Mortality rates at the injured sites were also higher than reference sites. After one year of deployment, more corals settled on limestone plates than on concrete or terracotta. Hence, recovery on injury sites may be hampered by high juvenile coral mortality rates, and the choice of substrate materials used in restoration may influence recovery.