Differing lesion recovery rates of two Caribbean stony coral species across a shallow water to mesophotic depth gradient suggest different sensitivity to repeated disturbance

Following major stress events such as storms, bleaching events, or disease outbreaks, surviving corals must regenerate tissue to recover. We aimed to understand how this recovery changes across depth, hypothesizing that deeper corals would regenerate more slowly and that this may limit resilience to acute stressors. Two species of reef-building coral, Orbicella franksi (an intermediate-depth species) and Agaricia lamarcki (a depth-generalist), were tagged at selected sites across their overlapping depth range of 13–41 m and directly monitored for recovery from experimentally generated lesions across time. Overall, recovery rates were distinct between species and across depths, with O. franksi recovery rates showing high variability and declining at depth. In contrast, A. lamarcki maintained similar rates of recovery across the examined depth range. The consistent response of A. lamarcki suggests that it can attenuate its biology with changing light resources to maintain healing abilities in different environments. Recovery rates were additionally compared against environmental and biological covariates and it was found that only increased initial lesion size had a significant positive effect on tissue regeneration rates for A. lamarcki . Collectively, this suggests that some mesophotic coral reefs, despite having high coral cover, may be slower to recover from stress events if dominated by non-depth-generalist species, such as O. franksi , resulting in increased vulnerability to repeated stress events.