Effects of substratum on the growth and survivorship of Montipora capitata and Porites lobata transplants

• Coral transplants do not exhibit a distinct substrate affinity.
• Initial mortality rates of coral transplants are related to the amount of epoxy used.
• Coenosarc tissue growth rates are not constant over time.
• Coral transplants of the same species will fuse together, if placed in close proximity of one another.

Artificial transplantation of corals is a common method used to restore damaged or unhealthy coral assemblages. Though a number of studies have successfully transplanted coral fragments, there is no general consensus on the type of substratum to be used. The present study focused on the growth and survivorship of Montipora capitata (rice coral) and Porites lobata (lobe coral) fragments, which were transplanted onto different natural and synthetic substrata. No significant differences in coenosarc tissue growth or survivorship were observed between the species. Measurements after 184 days of growth, found transplant growth to be significantly higher on rhyolite breccia and amorphous coral skeletons than on black ʻAʻā lava. Nevertheless, no significant differences were observed between any of the other substrata. After 365 days of growth, survivorship was also observed to not be significantly different between substrata; with the only exception of being lower on glass substratum. It is hypothesized that success in a coral reef restoration project is largely determined by the actual coral fragmentation and transplantation process; as no distinct substratum affinity was observed for M. capitata and P. lobata transplants.