Mueller Coral reefs are important reservoirs of biodiversity and serve as centers of biological production in low productivity seas. They provide subsistence and commercial fishing and contribute to third world economies by attracting tourism. It has become increasing apparent that reefs are being adversely affected by human activities. The impact of anthropogenic activities, both historical and modern, is damaging reefs to the point whether ecosystem functioning has been compromised. Restoration of reef fisheries and habitats is in its embryonic stages. Lessons learned from terrestrial and near-shore restoration programs are being examined to avoid costly or damaging errors. However, the logistics of working on reefs and their complex nature require new approaches. There is a good foundation of coral physiology and reef ecology research on which to base restoration efforts. This project includes two closely coupled components: 1) examination of coral growth and physiology under laboratory culture conditions and 2) assessment of coral contribution to habitat structural a biological complexity and survival rates of laboratory -raised corals in field test plots. This project will examine the effect of photoperiod and substrates on coral growth rates and metabolic performance (photosynthesis, respiration and calcification). These data will be used to modify culture techniques which have significant advantages over simple transplantation strategies. Corals are generally slow-growing species and optimizing growth rates to attain coral of critical size will be fundamental to the success of a culture approach. The critical size will be assessed in field pilot studies. Test plots will be established in a vessel grounding site. Plots will include corals grown under various culture conditions (explants) and to varying sizes. Their effect on habitat structural complexity and the resulting biodiversity will be compared to corals transplanted from healthy reef areas and to natural control s ites. Survivorship and growth rates of cultured explants and transplanted corals will also be compared. Results obtained from this project should provide both physiological and ecological information for the formulation of viable restoration programs. In addition, the further development of coral culture will assist reef conservation efforts by reducing the increasing wild harvest of corals for commercial trade.