Internal macrobioerosion on five species of Acropora following the 1998 bleaching event: Implications for the long-term impact of bleaching on the Great Barrier Reef

While bleaching events have received wide public attention, little attention has been given to the follow on effects on coral reefs. Bleached colonies of five species of Acropora of known age were sampled to study rates and agents of internal bioerosion at two sites on the southern Great Barrier Reef. The dominant erosion agents were worms and sponges and up to 23% of branches were eroded after 37 months. Significant differences were exhibited between species and between sites in terms of the animals responsible for internal erosion. The significance of bleaching and subsequent death of coral colonies is discussed with regard to their increased susceptibility storm damage and the loss of associated fish and invertebrates dependent on these habitat forming corals.