Rearing juvenile ‘corals of opportunity’ in in situ nurseries – A reef rehabilitation approach for sediment-impacted environments

Abstract

Scleractinians which have recruited on unstable substrates could function as a source of ‘corals of opportunity’ (COP). This study investigated the rearing of juvenile ‘corals of opportunity’ in an in situ coral nursery to assist in the rehabilitation of reefs in sedimented environments. Juvenile COPs of Pectinia paeonia (n = 71) and Pachyseris speciosa (n = 45) were collected from coral reefs in Singapore, categorized into three size classes (0.1–1.5, 1.6–3.0, 3.1–4.5 cm) and monitored at an in situ coral nursery for five months. Pectinia paeonia juveniles had higher overall survivorship than P. speciosa (93.0 and 69.6%, respectively) and no significant differences in survivorship among the size classes for either species were observed. The mid-sized and large juveniles of both species grew faster than the small ones. Fortnightly sedimentation and growth rates of all size classes of juveniles were weakly correlated (R < 0.22). The study highlighted the feasibility of rearing juvenile COPs in nurseries as material to supplement reef rehabilitation efforts in locations with high sediment load and unconsolidated substrate.

Key words:

• Pachyseris speciosa
• Pectinia paeonia
• sedimentation
• Singapore
• unconsolidated substrate

Acknowledgements

We would like to thank Toh Kok Ben and Toh Tai Chong for helpful discussions, as well as members of the Reef Ecology Laboratory, National University of Singapore, for their invaluable assistance in field work and data analysis.

Editorial responsibility: Tom Fenchel