Contrasting recovery following removal of growth anomalies in the corals Acropora and Montipora

Abstract

Growth anomalies (GAs) in scleractinian corals drain energy from the host and can result in partial or entire colony mortality. Here I show that growth anomaly removal is an effective treatment for the branching coral Acropora acuminata, with 90% of subjects remaining GA-free 9 mo following the procedure. In contrast, the encrusting coral Montipora efflorescens did not respond positively to treatment, with GAs re-developing in 100% of treated subjects. There was no clear evidence that injuries sustained during GA removal increased susceptibility to GA development in either coral species. Based on these results, I hypothesize that the factors inducing GAs in Acropora acuminata are localized, whereas those in Montipora efflorescens appear more systemic throughout the colony-perhaps the result of a genetically-based factor, or a persistent causative agent such as a virus. GA removal may therefore be effective for targeted rescues of particular coral species and morphologies in reef systems with low overall disease prevalence and is likely to be most effective for scleractinian corals if complimented by management actions that address the ultimate drivers of GAs on coral reefs.