Coral reef restoration

Coral reefs are widely recognized for concentration of biological activity, fisheries and tourism, coastal protection. geological processes, and aesthetic wonder. A principal cause of reef damage in Florida is ships running into reefs. The other major human impact on Florida's reefs is dredging for beach renourishment and channel maintenance. In response to chronic reef damage, federal and state agencies and consultants have developed techniques to restore, as best possible, reefs impacted by human disturbance. These efforts include salvaging sponges and corals, removing loose debris from the reef, rebuilding three-dimensional (3-D) structures onto leveled-scarified reef surfaces, and transplanting sponges and corals back on the cleared reef surfaces. This paper presents an overview of restoration approaches; a discussion on legal and administration to both damage and restoration of these essential fish habitats; a brief review of some case studies; and a discussion of restoration success criteria. Salvage of corals and sponges is critical to the success of any reef restoration effort. If a living surface is allowed to sit on the sand for a few days, that surface will die. Often the grounded vessel will have crushed the reef, excavating sediments and rubble that end up as a berm of material behind the ship's resting position. Dealing with massive amounts of rubble debris is challenging. The options include leaving it in place and stabilizing it with cements; moving it a long way from the site and dumping it in deep water; or reconfiguring it by moving it off reef and building piles where it can do no harm. After the debris is moved off the reef platform, corals and other sessile benthic organisms (salvaged resources) can be transplanted on the damaged area. Monitoring is important to determine the success of the restoration and to look for ways to improve future projects. Sampling sites for monitoring should include restored areas plus a reference area (undamaged habitat of a relatively similar nature that is in close proximity) for comparison. The following questions should be addressed for any reef restoration project: are the transplanted organisms still secured to the reef? Is the vitality (color, disease, algal competition) of the transplanted organisms equivalent to the organisms in the reference sites? Is recruitment (settlement of juvenile organisms) similar in the restored areas and the reference areas? Monitoring should be tied to decision making so corrections can be made. (C) 2000 Elsevier Science B.V. All rights reserved.