Stony Coral Transplantation Associated with Coastal and Marine Construction Activities

Coral reefs in Broward County are increasingly threatened by coastal and marine construction activities. Infrastructure installation (cables, pipelines, and sewer outfalls), beach renourishment, and dredge and fill operations have both anticipated and inadvertent impacts which may result in reef damage. Mitigation practices consisting of impact avoidance and minimization are necessary to prevent and offset reef damage. Coral transplantation is a commonly utilized impact minimization tool which aims to protect corals threatened by impending construction projects. Coral colonies are removed from their natural habitats and relocated to analogous unthreatened sites prior to construction. This study focuses on coral transplantation that occurred as impact minimization for two recently completed coastal and marine construction projects in Broward County. The first project involved relocation of colonies to natural reef away from potential damage by a natural gas pipeline geotechnical survey. The second project involved relocation of colonies to an artificial reef in relation to a beach renourishment project. Colonies from both projects were monitored and analyzed in regards to survival and growth to determine transplantation success. A combined 1100 colonies were transplanted for these projects, with approximately 25% of these chosen for 18-24 months of monitoring. The projects had high attachment rates between 92-100% and survival rates between 87-99%. A majority of colonies exhibited positive growth at an average rate of 0.03%-0.04% of initial tissue area per day. There were no apparent detrimental effects of transplantation such as reduced initial growth rates, disease, bleaching, or increased partial mortality. These results indicate that coral transplantation was highly successful from a biological standpoint. This study also demonstrates that coral transplantation is a valid and effective component of impact minimization whereby colonies that may otherwise be destroyed, can be successfully preserved. For this study, coral transplantation proved to be an economically worthwhile method of conserving an ecologically and economically valuable reef resource. However, coral transplantation is only one facet of impact minimization and mitigation. Ideally, future mitigation projects should also aim to reduce habitat loss and preserve biota in addition to stony corals