Species traits as indicators of coral bleaching

Coral bleaching as a response to increased sea surface temperature is regularly surveyed, but our understanding of species-specific differences in response is limited. We compiled bleaching response data for multiple warming events in which corals were identified to species and then quantified the relationship between species’ traits and their general bleaching response. Coral family explained more variation between species bleaching responses (11%) than any other individual trait. Other morphological and physiological traits explained between 6.7 and 10.5% of total variation; however, the majority of variation was attributed to differences rather than any coral trait. Some relationships between bleaching response and species traits (e.g., symbiont genotype) vary greatly by study, suggesting that plasticity among individuals related to their history and characteristics of the location or warming event are stronger determinants of bleaching response than species-level traits. Conversely, other traits (e.g., family and growth form) describe enough variation in bleaching responses among species to be useful as predictors of bleaching in species assemblages. Discriminating among higher level coral taxa (family) in conjunction with recording colony growth form would significantly improve the capacity to predict assemblage responses to warming events.