Assessing Acute Thermal Assays as a Rapid Screening Tool for Coral Restoration

Escalating environmental threats to coral reefs coincides with global advancements in coral restoration programs. To improve long-term efficacy, practitioners must consider incorporating genotypes resilient to ocean warming and disease while maintaining genetic diversity. Identifying such genotypes typically occurs under long-term exposures that mimic natural stressors, but these experiments can be time-consuming, costly, and introduce tank effects, hindering scalability for hundreds of nursery genotypes used for outplanting. Here, we evaluated the efficacy of the acute Coral Bleaching Automated Stress System (CBASS) against long-term exposures on the bleaching response of Acropora cervicornis , the dominant restoration species in Florida’s Coral Reef. Comparing bleaching metrics, F v / F m , chlorophyll, and host protein, we observed similar responses between the long-term heat and the CBASS treatment of 34.3°C, which was also the calculated bleaching threshold. This suggests the potential of CBASS as a rapid screening tool, with 90% of restoration genotypes exhibiting similar bleaching tolerances. However, variations in acute bleaching phenotypes arose from measurement timing and experiment heat accumulation, cautioning against generalizations solely based on metrics like F v / F m . These findings hold promise for improving the efficacy of screening coral restoration genotypes and determining their relative tolerance for restoration interventions.