Fig 1.
Location of the four sentinel sites.
The Boot Key Patch Reef and East Washerwoman Shoal sites are patch reefs located shoreward of the offshore bank reef system. The Grouper Reef and Sombrero Reef sites are located on offshore bank reef habitat.
Fig 2.
Photographs of SCTLD-affected coral colonies.
Coral colonies showing signs of SCTLD. (A) Diploria labyrinthiformis. (B) M. meandrites. (C) P. strigosa. (D) Siderastrea siderea.
Table 1.
Coral species identified on at least one of the sentinel sites.
Fig 3.
Size frequency histograms summarizing coral colony size as total skeletal surface area.
Site-level coral community size structure estimated from the baseline surveys of the sentinel sites conducted from January 10 through February 2, 2018. Colony size structure estimated calculating SA for each colony. SA for each coral colony was derived using its width, length, and height measurements taken during the baseline surveys and calculating area as an idealized hemi-ellipsoid.
Fig 4.
Coral community composition at the four sentinel sites.
The mean (±1SE) number of coral colonies per m2 and mean (±1SE) living coral tissue (m2), per m2 at each of the four sentinel sites observed during the baseline surveys conducted January 10 through February 2, 2018. Living coral tissue was derived by first estimating SA for each coral colony using its width, length, and height measurements taken during the baseline surveys and calculating area as an idealized hemi-ellipsoid. The area of living tissue was then estimated from the proportion of the colony SA observed with of living tissue relative to the total colony area.
Fig 5.
Time series of the disease status of coral colonies.
Status is defined as: i) not diseased, ii) diseased, and iii) dead. Status is summarized as the percent of total colonies per site from late January 2018 through mid-September 2019. Observations were made bimonthly through July 2018 and monthly thereafter.
Fig 6.
Time series summarizing living coral tissue and bleaching.
(A) Mean (±1SE) percentage of living coral tissue per colony for each of the sentinel sites from early February 2018 (before SCTLD was observed) through September 2019 (replicate plots pooled). Observations were made bimonthly through July 2018 and monthly thereafter. (B) The percentage of coral colonies that were either partly or fully bleached by site over the same time frame.
Fig 7.
SCTLD status of coral colonies, by species, September 2019.
Disease status (Not diseased, diseased, dead) is pooled across sentinel sites. Numbers at the top of the bars represent the number of colonies observed during the September 2019 monitoring period. Numbers at the base of the bars indicate the number of colonies not observed during that monitoring period.
Fig 8.
SCTLD status of coral colonies during September 2019, by species.
(A) The Boot Key Patch Reef and East Washerwoman Shoal inshore sentinel sites and (B) the Grouper Reef and Sombrero Reef offshore sentinel sites. Diseased colonies defined as SCTLD-inactive are those that showed signs of the disease before July 2018, remained alive, but exhibited no tissue loss after that month. Colonies defined as SCTLD-active were either diseased by July 2018 and continued to lose living tissue or became diseased after July 2018. Numbers at the top of each bar represent the number of colonies observed during the September 2019 monitoring period. Numbers at the base of the bars indicate the number of colonies not observed during that monitoring period.
Fig 9.
Estimated SA of living coral tissue.
The mean (±1SE) living coral tissue (m2), per m2 by species at each of the four sentinel sites observed during the baseline surveys conducted January 10 through February 2, 2018 and the surveys conducted during September 2019.
Fig 10.
Graphical summation of the odds ratios derived from the transmission model.
(A) Odds ratios associated with a non-diseased colony becoming diseased when its nearest neighbor was diseased; (B) Odds ratios associated with a non-diseased colony becoming diseased when its nearest neighbor was dead; (C) Odds ratios associated with a colony becoming diseased in relation to the distance to its nearest neighbor; (D) Odds ratios associated with a non-diseased colony becoming diseased in relation to the distance to its nearest diseased neighbor; (E) Odds ratios associated with a non-diseased colony becoming diseased in relation to the distance to its nearest dead neighbor; (F) Odds ratios associated with a non-diseased colony becoming diseased in relation to its SA.
Table 2.
Parameter estimates of the dynamic multistate model relating neighbor status and distance to nearest neighbor to the probability of being diseased (i.e., affected by SCTLD).