A mid-water coral nursery

The nursery component in an active reef restoration program is used as a tool that provides coral source material for the rehabilitation of denuded reef areas. Here, we present the first mid-water floating coral nursery, an improved prototype of earlier attached-tosubstrate coral nurseries. A total of 7119 fragments sampled from 11 branching species and 21 intact colonies of Favia favus were maricultured at six meter depth, 14 m above sea bottom in close vicinity to fish farm facilities and 8 km away from the coral nature reserve, at Eilat, Red Sea. Total mortality of fragments during 10 nursery months was very low (less the 10%) while growth rates were high (up to 6 fold in height). The massive coral F. favus showed zero mortality and an average growth rate of 159% during 270 nursery days. We conclude that floating nurseries, installed away from major reef structures, improve coral culturing as compared to attached-to-substrate nurseries by providing better water and nutrient fluxes, promoting the elimination of sediment, improving cleaning by whole nursery movements, and providing optimal PAR to maricultured coral colonies through depth adjustment. In addition, detrimental impacts caused by recreational activities and corallivorous organisms are eliminated.