Influences of genotype, phenotypes, and size characteristics on lesion recovery in Caribbean staghorn coral

Abstract

Severe declines of coral cover in the Caribbean and throughout the world have led scientists and managers to invest in restoring coral reefs and determining which coral phenotypes and genotypes will maximize restoration success. Acropora cervicornis is the species most commonly used by restoration programs in the Caribbean, but only a handful of studies have documented its capacity for wound healing, a phenotype identified as essential for predicting genotype performance. Here, we examined the influence of genotype, lesion area, colony size, and growth, along with tissue, chlorophyll a, lipid, and symbiont densities, on the recovery capacity of staghorn corals in a field experiment. Colonies with smaller lesion areas, lower tissue densities, and greater chlorophyll a densities healed more efficiently 9 d after wound infliction. At 16 d, initial colony size was the only significant predictor variable, with smaller colonies healing more quickly. Healing rate varied significantly by genotype, ranging from 50 to 100% of fragments healed by genotype 16 d after wounding. Colony growth was not predictive of recovery rate, but wounded corals grew more slowly than non-wounded corals, providing evidence for a tradeoff between these 2 phenotypes. We encourage restoration practitioners to fragment smaller colonies and generate smaller lesions in the interest of rapid wound recovery. We also recommend that practitioners identify rapidly healing genets not from tissue assays but through lesion recovery tracking and outplant these genotypes in higher abundance at restoration sites, particularly in high-energy environments where colonies are vulnerable to fragmentation.