Coral reefs in the western Atlantic are declining drastically due to the emergence of stony coral tissue loss disease (SCTLD). Attempts to characterize the microbiome associated with SCTLD is difficult because baseline microbial knowledge of healthy corals is sparse, and past studies relied only on visual assessments of health state. To address this limitation, this study combines fate tracking and microbiome tracking of known healthy corals before and after SCTLD arrival. From <em>Colpophyllia natans</em> colonies, tissue and near coral seawater were sampled at U.S. Virgin Islands reefs that were not yet affected by SCTLD. After SCTLD appeared on the reef, coral and water samples were taken from the same colonies at 1, 2, 4, and 6 weeks and at 6 months. The 16S ribosomal RNA gene of the bacteria and archaea in the coral and water samples was sequenced to quantify the microbial communities through time. Of the 13 colonies, 10 became affected by SCTLD. Most colonies experienced total mortality, but three showed halting of lesions. Distinct microbial signatures of SCTLD were found in both sample types, but the disease signal was surprisingly stronger in the seawater than the coral tissue. Seawater microbes exhibited more community level changes than the corals over time. Both seawater and tissue of diseased colonies displayed increases in Campylobacterota, Firmicutes, and Desulfobacteria. By combining fate tracking with microbiome data, this study sheds light on the dynamic nature of the interaction between coral microbiome and health state.

Primary Presenter: Jeanne Bloomberg, Massachusetts Institute of Technology, Woods Hole Oceanographic Institution (jeanne.bloomberg@whoi.edu)

Authors:

Sarai Hutchinson, University of the Virgin Islands  ()

Cynthia Becker,  Massachusetts Institute of Technology, Woods Hole Oceanographic Institution  ()

Sonora Meiling, University of the Virgin Islands  ()

Bradly Arrington, University of the Virgin Islands  ()

Marilyn Brandt, University of the Virgin Islands  ()

Amy Apprill, Woods Hole Oceanographic Institution  ()