Sponge abundance and the prevalence of disease on scleractinian coral in Bonaire, Dutch Caribbean
Sponges are important to reef health, fulfilling a number of structural and functional roles. Despite the wide range of functions they provide, limited research on sponges has been conducted. Their ability to filter the water column of nutrients is essential to keeping the water around reefs clean. Coral reef diseases are becoming more widespread due to multiple factors such as pollution and eutrophication. This study assessed the possible relationship between sponge abundance and disease prevalence in Bonaire, Dutch Caribbean, by using 10 m x 2 m belt transects photographed into 1 m x 1 m quadrats. Per transect, 10 randomly selected photographs were analyzed using Image J to find the total area of sponges and live and diseased coral. Less than 1% disease was found at the study sites because the majority of the coral in the quadrats was partially or completely dead. No correlation was found between disease and sponge coverage. However, a significant correlation was found between percent sponges and live coral coverage. Although there was no correlation found between sponge cover and disease prevalence, the relationship between live coral and sponge is of particular importance for reef health monitoring across the Caribbean.