DAO prepress abstract   -  DOI: https://doi.org/10.3354/dao03807

ABSTRACT: Coral reefs are lately suffering a fast decline in biodiversity due to the coupled effect of climate change and disease outbreaks, which in recent decades have been reported with higher frequency and shorter intervals. Limited studies have been conducted on coral diseases in the Maldives resulting in the impossibility to assess the temporal trend in their dynamics. In this context, we evaluated the change in the distribution, prevalence, and host range of four diseases, namely black band disease (BBD), brown band disease (BrB), skeletal eroding band (SEB) and white syndrome (WS), in the reef system around Thudufushi Island after twelve years from the previous report published in 2015 by Montano et al. In this period, the overall disease prevalence increased, except for BrB, with SEB showing the most severe increase in 2022 with respect to 2010. The overall average prevalence of coral diseases is approximately 2%, indicating an increase of about 0.7% from 2010. Diseased coral colonies were found in all the investigated sites, with the east site being the most affected and SEB emerging as the most prevalent disease across all the investigated sites. The affected colonies belong to 13 genera, with Psammocora genus showing the highest overall mean disease prevalence. This study depicted a basic temporal trend in disease prevalence that confirms an increase of coral diseases in the region and calls for a dedicated national monitoring protocols to better understand and predict future coral disease dynamics at regional scales.