November 1989 was a very bad month for the coral reefs of the Key Largo National Marine Sanctuary. In unrelated incidents two large ships, the M/V Elpis and the M/V Alec Owen Maitland , ran hard aground on shallow sanctuary reefs, devastating the impact areas, killing or displacing corals, sea fans, and fish, and destroying the physical structure of the underlying reef framework. NOAA sanctuary staff immediately conducted an ecological survey of the impacted habitats. This crucial data on the nature and extent of resource loss formed the basis for a successful natural resource damage claim brought against the responsible parties by NOAA's Damage Assessment and Restoration Program (DARP). Funds exceeding $3 million were recovered to offset costs of the emergency response, damage assessment and restoration of the impacted habitats. These two devastating groundings were important factors in the Congressional designation of the Florida Keys National Marine Sanctuary.

The physical destruction of the reef, aggravated by the ships' attempts to "power off" the reef, was so severe that no significant ecological recovery could occur until the underlying reef framework was repaired. The option of leaving the sites alone was considered, but it became clear that the damaged area would enlarge without help; loose pieces of broken coral threatened to smash the surrounding reef in rough weather. NOAA devised a plan with two phases. Phase I of the Elpis/Maitland (E/M) Restoration Project concentrated on structural restoration of the reef by removing coral rubble, stabilizing the underlying reef structure, and recreating the original topography of the habitat. Phase II, begun in late 1995, accelerates the recovery rates by transplanting corals and other reef-dwelling animals onto these now-repaired habitats.

The E/M Restoration Project developed and tested a suite of new restoration methods. Central in the plan are custom-designed "reef replicating modules" which fill massive expanding holes in the reef framework. Forty modules, weighing 10 tons each, were fabricated of special marine cement and natural quarried coral reef rock to recreate the shape, texture and composition of the lost habitat. Phase I construction began in July 1995 and was successfully completed in early September 1995.

Installing these modules required a flotilla of barges, tugboats, supply vessels and cranes, and careful planning and coordination to avoid additional damage to sensitive reefs. In addition to technological and engineering design innovations achieved in Phase I, Phase II of the E/M project will accelerate ecological recovery rates by enhancing populations of reef-dwelling animals in the restored sites. This effort, and the associated ongoing ecological monitoring program, will provide unique scientific insight into the fundamental relationships between habitat structure and the ecology and management of coral reef environments.

Original article by Dr. Charles Wahle (NOAA).
Edited for the Web by Daniel Gomez-Ibanez.