Methods to enhance sexual recruitment for restoration of damaged reefs

Natural recruitment of scleractinian corals is highly influenced by various environmental effects, Predation, sedimentation, algal growth and grazing may cause high mortality rates in larvae and settlers. In the past, methods have been developed to produce large quantities of planulae. Under laborat ory conditions the survival of ex situ produced propagules can be optimized to obtain large amounts of sexual recruits. Sexual recruitment plays an im portant role in conservation management, especially for the preservation of genetic diversity in natural and ex situ populations. We carried out pilot studies which indicate the possibility to transport, settle and recruit sc leractinian corals, here Acropora florida Dana 1846, in closed-system aquar ia using artificial seawater. After further development, this method promis es to be an economical and effective way to mariculture corals for restorat ion of damaged reefs. To fulfill this aim, collaboration with commercial co ral farms and public aquaria should be envisaged. Coral farms that provide work for coastal populations can play an important role in mariculturing se xual settlers. Such farms could produce thousands of propagules for reef co nservation and even more for the aquarium trade thus reducing natural colle ction of corals and providing financial support by resulting incomes. Publi c aquaria may help to optimize this method.