Coral diseases near Lee Stocking Island, Bahamas: patterns and potential drivers

The number of coral diseases, coral species they infect, number of reported cases, and range over which these diseases are distributed have all increased dramatically in the past 3 decades, posing a serious threat to coral reef ecosystems worldwide. While some published studies provide data on the distribution of coral diseases at local and regional levels, few studies have addressed the factors that may drive these distributions. We recorded coral disease occurrence, prevalence, and severity along with temperature, sedimentation, and coral population data (species abundance and colony size) over 2 consecutive summers on reefs near Lee Stocking Island (LSI) in the Bahamas' Exuma Chain. In 2002 a total of 11092 coral colonies (all species present) were examined within a survey area of 9420 m2, and 13 973 colonies within 10 362 m2 in 2003. Similar to other reports, relatively large, framework species including Siderastrea siderea, Colpophyllia natans, and Montastraea annularis, along with the smaller Dichocoenia stokesi, were the species most susceptible to coral disease. Recurring infections were observed on individual colonies from 2002 to 2003, and were more likely for black band disease (BBD) than for either white plague (WP) or dark spots syndrome (DS). In 2002, WP and DS demonstrated clumped distributions, while BBD was randomly distributed. However, in 2003 BBD and WP were clumped. This is the first study, to our knowledge, that quantitatively documents coral disease dynamics on reefs surrounding LSI.