Project: RAPID: Leveraging a Natural Bleaching Event to Assess Links between Bleaching and Disease

NSF Award Abstract:

Stony corals, the foundation of coral reef ecosystems, are facing significant population declines due to a range of environmental conditions, including increasing sea surface temperatures. These warmer waters are leading to a rise in the occurrence of infectious disease outbreaks and increased periods of intense high temperatures that result in coral bleaching. The ongoing devastating disease outbreak in the Caribbean coupled with the high temperatures of summer 2023 have exposed Caribbean corals to a unique combination of deadly stressors. The research team is leveraging these environmental conditions, along with robust historical data, to investigate the mechanisms which link coral bleaching to disease susceptibility. These data provide novel insight regarding coral resilience to improve management and conservation of these important ecosystems and the team is working directly with practitioners to disseminate project results. The project also provides research and educational opportunities for multiple undergraduate students at minority serving institutions.

Scleractinian corals have faced significant mortality in recent decades due to a diversity of anthropogenic stressors, most prominently the interacting stressors of rising sea surface temperatures and epizootic outbreaks. Notably, thermal anomalies resulting in coral bleaching and coral disease outbreaks are often linked, sometimes in asynchronous patterns. Corals in the Caribbean have been experiencing a significant mortality from a novel disease (Stony Coral Tissue Loss Disease, SCTLD). Additionally, record high temperatures in summer 2023 have triggered a massive region-wide bleaching event. This project leverages these unique ongoing environmental conditions, combined with a robust historical physiological data set, to investigate the mechanisms linking thermal stress response to disease susceptibility in corals. The team is monitoring and sampling corals known to be SCTLD-resistant for one year from the peak of bleaching through recovery, tracking bleaching & disease outcomes, host immunity/physiology, and symbiont communities (microbiome and photosymbiont). These data are being compared to historical physiological data collected before and during the initial SCTLD outbreak to characterize the mechanisms linking bleaching recovery to disease susceptibility. The results of this study provide unprecedented new insights regarding the cellular mechanisms linking bleaching and disease susceptibility in corals, improving general understanding of multi-stressor response in marine organisms.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.