Spatial epidemiology of Caribbean yellow band syndrome in Montastrea spp. coral in the eastern Yucatan, Mexico

Caribbean yellow band syndrome (YBS) is a poorly understood, progressively fatal disease primarily affecting Montastraea spp. coral. This disease has exhibited rapid spread throughout the entire Caribbean over the last few decades. In this study, geographical information systems (GIS) and spatial statistics were used to analyze the distribution of YBS in Akumal Bay, Mexico, and host and environmental risk factors for YBS were evaluated epidemiologically. In this Bay, there are hundreds of colonies of Montastraea annularis from I in depths inside the fringing reefs to reef crests and beyond. Of 63 corals that were evaluated, the overall prevalence of YBS in Akumal Bay was 28.6\%, with 35.7\% in large colonies, 23.8\% in medium-sized colonies, and 23.8\% in small colonies, where small colonies were < 200 cm diameter, medium-sized were 200-500 cm, and large were > 500 cm. Lesions covered 3.8\% ( +/- 1.3 s.e.) of the surface of colonies assessed, compared with a mean percentage of dead colony cover of 54.4\% ( +/- 4.2 s.e.). Analysis for spatial clustering documented that M. annularis colonies (well and sick) were highly spatially clustered, compared to expected complete spatial randomness. However, compared with all M. annularis corals, colonies with YBS tended to be less spatially clustered (i.e. within the overall clustered spatial distribution of M. annularis colonies, YBS-affected colonies' distribution was more regular). These findings are consistent with several hypotheses for the etiology of YBS, including near-shore pathogens or toxins either directly inducing disease or indirectly leading to disease by increasing host susceptibility. Ongoing investigations into the management and cause of YBS can use this information to develop management strategies and more efficiently target future sampling.