Effects of macroalgae on corals recovering from disturbance

Abstract

Corals have an ability to recover from disturbance through the regeneration of tissue, but macroalgae are believed to impede this process. In this study, the type of benthic macroalgae deposited on coral skeleton was manipulated experimentally, and the effects on tissue regeneration and skeletal growth of two common coral species Acropora pulchra and Acropora aspera were observed after disturbance. Macroalgae, common to the study region, but from variable functional groups, were investigated for their influence on coral growth. The green filamentous macroalga Chlorodesmis fastigiata significantly reduced tissue recovery in A. pulchra, but not in A. aspera. It led to the infection of A. pulchra with ciliates. The brown seaweed, Lobophora variegata, the encrusting coralline alga Porolithon (= Hydrolithon) onkodes, and turf algae, had only minor effects on coral recovery. This suggests that the outcome of the regeneration process is highly variable and dependent upon both, the species of coral and algae involved.