Meeting Abstract
Herbivores play an important role in coral reef communities by preventing the overgrowth of coral by macroalgae. However the interactions of these herbivores may actually facilitate the growth of macroalgae rather than its removal. Previous studies have found that small reef herbivores, such as damselfish, are fierce defenders of their algal gardens and have the potential to limit the grazing of larger herbivores such as parrotfishes. In this study, we examined the abundance and species composition of damselfish across 14 reefs of the Florida Keys National Marine Sanctuary known to vary in coral and macroalgae cover. We utilized a combination of direct observations and remote videos to record the behavioral interactions of damselfishes and parrotfishes. Damselfish abundance was unrelated to algal cover or parrotfish biomass, but increased significantly from inshore to offshore. Algal cover was not significantly different inside versus outside of damselfish territories. Damselfish aggression differed by species, and was positively related to both damselfish and parrotfish densities, but was unrelated to body size, territory size, algal cover or individual boldness. A majority of aggressive acts were directed toward other damselfish rather than larger herbivores like parrotfish. These results suggest the presence and behaviors of damselfish may not strongly influence algal cover or the herbivory of parrotfishes.
