Assessing the Thermal Tolerance on Genotypic Variability in Acropora cervicornis and Acropora palmata Corals maintained in an offshore nursery in Broward County, Florida

Assessing the Thermal Tolerance on Genotypic Variability in Acropora cervicornis and Acropora palmata Corals maintained in an offshore nursery in Broward County, Florida

Alvin Sherman Library

Global warming and constant stressors are threatening the most diverse and abundant reef-building coral, causing their rapid decline. Elevations in ocean temperature have contributed to massive bleaching events and increased mortality in key coral species throughout Florida. The degradation of coral ecosystems not only reduces marine biodiversity but also threatens fisheries, coastal protections, and tourism that depend on healthy reef systems. In response, coral nursery programs have arisen as a conservation strategy for restoring reefs. Acropora species, particularly Acropora palmata and Acropora cervicornis, are among the most widely used corals in restoration due to their fast growth, large branching morphology, diversity, and abundant genera on Florida reefs. Since 2007, Nova Southeastern University has concentrated efforts on coral restoration through an offshore coral nursery, where 4,000 corals from different genotypes and origin locations are maintained and monitored. Given the coral mortality in the nursery resulting from repeated bleaching events, this study aims to identify corals exhibiting traits that would enable them to survive under future climate projections, as well as to assess regional differences in thermal tolerance between genotype origins, including Broward, Miami, and Florida Keys. The mean bleaching severity was higher for Broward compared to Miami. The ANOVA test indicated the results were statistically significant, with p-values of 1.15E-22 and 1.9E-05, showing a higher coral performance in Miami than in Broward genotypes due to lower bleaching severity. By identifying temperature-resilient genotypes, this study offers valuable insights to improve the advancement of effective coral restoration, ultimately promoting coral restoration success.