Philippine Science Letters
vol. 4 | no. 1 | 2011
published online June 3, 2011


ARTICLE


Factors promoting coral-algal transition
in coral transplantation experiments


by Helen T. Yap1*, Reverie Alvarez-Molina1,2, Caryl S. Benjamin1

1The Marine Science Institute, University of the Philippines,
Diliman, 1101 Quezon City, Philippines
2(Present address) Westminster Christian School, 6855 SW 152 Street,
Palmetto Bay, FL 33157,U.S.A.



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Coral transplantation experiments can provide a useful platform by which to examine the overgrowth of coral by algae under different environmental conditions. The proliferation of algae on coral reefs is a serious concern at present. Under optimal conditions for coral survival and growth in the field, algal overgrowth was made possible only after extensive damage to coral tissue by gastropod predation. This was not the case, however, in land-based tanks where conditions were suboptimal for coral growth and survival, and where there was an absence of both predators and herbivores. As coral tissue deteriorated, high nutrient conditions appeared to promote a greater abundance as well as diversity of algae, notably Enteromorpha, Cladophora, Ceramium and Centroceras. In contrast, algal cover on coral transplants in the field was dominated by the genus Hypnea. Composition and percentage cover of algae did not differ significantly between previously live transplants and dead coral skeletons in most treatments (two different coral species, field versus land-based tanks). There was also no significant difference in algal colonization of previously live transplants of two coral species, Porites cylindrica and P. rus. The above findings are relevant to understanding coral-algal dynamics under conditions of human induced perturbation (e.g., the depletion of herbivores, high nutrient loading). In addition, these results suggest developmental trajectories a coral community can undergo following such perturbation because different algal genera presumably are grazed on by different species of herbivores, and hence support different trophic pathways.


*Corresponding author
Email Address: helentyap@yahoo.com
Submitted: February 4, 2011
Revised: May 3, 2011
Accepted: May 6, 2011
Published: June 3. 2011
Editor-in-charge: Gisela P. Padilla-Concepcion
Reviewers:
James R. Guest
Wilfredo R. Licuanan
Magnus Nystrom