PhD Defense Seminar cum Oral Examination
“The use of sexually propagated scleractinian corals for reef restoration”
Toh Tai Chong
Dept. of Biological Sciences, NUS
Supervisor: Prof Chou Loke Ming
Fri 05 Sep 2014: 3.30m
DBS Conference Room II (S1 Level 3, Mezzaine)
All are welcome
“Increasing anthropogenic pressures coupled with global climate change have resulted in the rapid degradation of coral reefs, necessitating the implementation of active measures to assist the recovery process. Recent advancements have facilitated the use of sexually propagated scleractinian corals to supplement reef restoration initiatives, by capitalizing on the ability of corals to produce large numbers of genetically diverse propagules. The main objectives of my thesis were to assess and improve the feasibility of using sexually propagated scleractinian corals for reef restoration.
Attempts at transplanting sexually derived corals are limited and have been restricted to the use of the fast-growing species. This is the first study to rear two species of slow-growing Faviid corals from larvae through to transplantion to the reef. My results demonstrated that this technique is technically viable for reef restoration and the key bottleneck of this approach resided in the initial ten months of the ex situ mariculture phase, which had the highest juvenile coral mortality rate.
To improve the feasibility of this approach, I have demonstrated that introducing the sea urchin Salmacis sphaeroides and the gastropod Trochus maculatus as biological control agents were useful in regulating macroalgae proliferation and augmenting the post-settlement growth and survival of coral juveniles in mariculture facilities. Subsequently, I have showed that nutritional enhancement significantly increased the ex situ growth of coral juveniles. This had significant flow-on effects even after transplantation to the reef, as coral transplants which were fed had higher growth and survival rates than those which were not.
Taken together, my research provided key empirical evidence to support the use of sexually propagated corals as source material for transplantation to degraded reefs. The initatives proposed in this study can be incorporated into future reef restoration programmes to improve the feasibility and cost-effectiveness of transplanting sexually propagated corals.”