EFFECTS OF THE THREESPOT DAMSELFISH, STEGASTES PLANIFRONS ON A PATCH REEF SYSTEM: A STUDY OF DAMSELFISH AND URCHINS AT CORAL GARDENS, BELIZE

There is a growing concern about decreased global biodiversity in general and especially the decline of frame building acroporid species of Caribbean coral reefs. This study examines a possible refugia for Acropora cervicornis coral in the back-reef area of Ambergris Caye, Belize commonly referred to as Coral Gardens. Our goal is to understand the carbonate budget and ecosystem dynamics of this successful reef with emphasis on the role of herbivorous damselfish and urchins. Benthic survey data from photo-quadrats along eight transects was supplemented with counts of urchins in various size classes. The number and species of damselfish and a count of damselfish chimney scars was also collected. The data, while preliminary, indicate a positive correlation between the density of Stegastes planifrons and the abundance of urchins (R² up to 0.78). It has been suggested that damselfish will remove urchins from their territories; while our data does not dispute this behavior it does suggest that this behavior is correlated to the size class of urchins (R² up to 0.76). Further analysis will investigate the roll of reef rugosity and live coral cover on these correlations and whether or not damselfish significantly reduce urchin bioerosion as previously reported. We will also examine the impact of damselfish “gardening” and chimney scars on the carbonate budget of these increasingly unique A. cervicornis reefs.