Optimal temperature regimes for land-based mariculture of tropical corals

摘要

Thermal tolerances of ten coral taxa in relation to their survivorship, health status and growth performance were examined. These coral microcolonies were subjected to temperatures of 26 degrees C, 28 degrees C, 30 degrees C and 32 degrees C for 2 months in an indoor recirculating aquaculture system (RAS). Not unexpectedly, most coral species tested thrived well between 28 degrees C and 30 degrees C, except for Acropora valida which fared best at 26 degrees C. However, subtle differences were apparent. Turbinaria mesenterina, Porites lobata/lutea, Pachyseris speciosa, Platygyra sinensis, Porites rus and Pavona frondifera thrived well at 28 degrees C whilst Dipsastraea speciosa, Pocillopora acuta and Podabacia crustacea, together with Tur. mesenterina and Pla. sinensis, performed better at 30 degrees C. Only Tur. mesenterina and Pod. crustacea survived at 32 degrees C. Amongst the coral taxa tested, Pla. sinensis depicted the highest growth rate of 1.4 mm/month at 30 degrees C, followed by Tur. mesenterina at 30 degrees C and Pod. crustacea at 28 degrees C where both grew at 1.0 mm/month. Dip. speciosa, Pla. sinensis and Pod. crustacea cultured at 30 degrees C were the least bleached. In response to elevated temperatures, the survival of laminar corals outperformed massive and branching corals. This thermal study suggests that all species tested can be ex situ propagated in RAS and Tur. mesenterina and Pod. crustacea are also suitable for transplantation.