Structural reef restoration and coral transplantation to the R/V Columbus Iselin grounding site in the Florida Keys National Marine Sanctuary

Restoration of damaged natural resources in the Florida Keys National Marine Sanctuary is mandated by US law. In 1994, the R/V Columbus Iselin ran aground at Looe Key Reef and severely damaged four coral reef spurs. Four years after the vessel grounding, Hurricane Georges further excavated reef framework from the injured areas. The extent and volume of the damage was determined from aerial photographs, diver observations, and high resolution bathymetric surveys. Coral spurs were reconstructed with quarried limestone boulders, fiberglass reinforcing rods and a specially formulated tremie-pumped concrete. On upper finished reef surfaces, exposed fresh concrete between boulders was ornamented with limestone rocks to increase surface rugosity and create a more natural appearance. In 2004, sixty eight coral colonies were transplanted and attached onto repaired spurs with underwater cement. Donor specimens were collected opportunistically from pier walls of the Key West Harbor.