No abstract

Transplantation of coral fragments is seen as a potential method to rapidly restore coral cover to areas of degraded reef; however, considerable research is still needed to assess the effectiveness of coral transplantation as a viable reef restoration tool. Initially, during restoration efforts, coral transplants are attached artificially. Self-attachment (i.e., growth of coral tissue onto the substrate) provides a more secure and lasting bond, thus knowledge about self-attachment times for corals is of importance to reef restoration. While it is known that coral fragments may generate new tissue and bond to substrata within a few weeks of transplantation, surprisingly little is known about the speed of self-attachment for most species. Two independent experiments were carried out to examine the self-attachment times of 12 scleractinian and one nonscleractinian coral species to a natural calcium carbonate substrate. The first experiment examined times to self-attachment in 11 species of differing morphologies from seven families over approximately 7 months, whereas the second experiment examined three fast-attaching Acropora species over approximately 1 month. In the first experiment, the branching species Acropora muricata had a significantly faster self-attachment time compared to all other species, while Echinopora lamellosa had the slowest self-attachment time. For the second experiment, A. muricata was significantly slower to self-attach than Acropora hyacinthus (tabular) and Acropora digitifera (corymbose-digitate). The results suggest that a combination of factors including growth rates, growth form and life history may determine how quickly fragments of coral species self-attach after fragmentation and transplantation.

ABSTRACT1. Nubbins from 12 coral species were transplanted onto dead giant clam shells at three sites in a lagoon near Bolinao, north-western Philippines. Transplants were attached using three types of adhesives: cyanoacrylate glue (SG), epoxy putty (EP) and marine epoxy (ME) and were monitored over five months for detachment, in situ mortality and natural self-attachment by tissue growth.2. Corals attached with SG showed a significantly higher rate of detachment (logrank test) than those attached with either EP or ME (P50.001 in each case). Also, those attached with EP showed a higher rate of detachment than corals attached with ME (logrank=6.46, P50.05).3. ANOVA (P>0.05) and survival analysis (logrank=2.85, P>0.05) showed no among-adhesives differences in in situ mortality. Among the species used, Porites cylindrica, Pavona frondifera, Heliopora coerulea and Porites rus had the highest survivorship with 82%, 80%, 76% and 73%, respectively, of nubbins alive at the end of the experiment and also displayed the highest cumulative rates of self-attachment. Species with the lowest survival rates included Acropora muricata and four pocilloporids.4. Although there was no significant difference in the number of self-attaching transplants among the adhesives, corals transplanted using ME and EP self-attached earlier than those transplanted using SG (logrank=11.19, P50.01).5. Results from this study highlight the importance of selecting the appropriate means of attaching corals to substrates and carefully considering species-specific traits of candidate corals for transplantation.

No abstract

Space is a limiting resource in coral reef communities causing actively growing coral colonies to come in proximity and interact with each other. Although most contact interactions among corals have been studied extensively, very few non-contact and non-aggressive interactions have been documented so far. We present results from a 3 yr field study of coral communities showing that, under unperturbed conditions, the reef-building coral Porites cylindrica exhibits significantly higher growth when transplanted together with 2 other species (P. rus and Pavona frondifera) than when grown in monoculture. However, the introduction of a chronic disturbance (nutrient enrichment) adversely affected its growth rates and survival, thus overturning the earlier trend. Furthermore, the 3 species used in the experiment exhibited different responses to the perturbation (negative, no effect, positive). Our results show that the presence of other species can enhance performance at the colony level, while differential species responses potentially provide buffering effects at the community level that may contribute to the maintenance of community structure and function during periods of disturbance.