Disease outbreaks on coral reefs are linked with increasing climate and human impacts. While anthropogenic pressures and anomalous temperature events negatively affect corals, they also promote predation by corallivores among susceptible corals. Previous research has suggested that corallivores serve as potential vectors of disease for reef-structuring corals; therefore, definitively establishing the role of corallivores in disease outbreaks has become increasingly important. In this study we conducted a systematic meta-analysis on literature which documents corallivore predation using standardized coral disease surveys to determine if there is sufficient evidence for corallivores as vectors for disease.
Results/Conclusions
Out of 1,860 independent studies on coral disease, only 50 studies recorded coral predation with most of the data surrounding crown-of-thorns starfish (32%) and the corallivorous snail, Drupella sp. (29%). However, few studies recorded fish corallivory, despite being considered a vector of disease (1% pufferfishes, 1% damselfishes, 4% parrotfishes, 7% butterflyfishes, 10% unspecified fish bites). The studies that record corallivory of COTS and Drupella sp. also documented many types of diseases, indicating that these studies have been thorough in describing reef health. Conversely, studies which note fish predation report very few diseases, indicating little evidence of an association between other corallivores with disease progression. We found that only 11 studies which specifically linked coral disease with corallivory showed clear results of COTS, snails (Drupella sp. and Coralliophila abbreviata) and fireworms (Hermodice carunculata) as vectors for certain diseases. Conversely, there is conflicting data that implicate any fish as a vector for disease. Our results indicate that despite initial claims that corallivory spreads disease, there is little evidence that demonstrates this relationship.