Resistance and resilience to coral bleaching: Implications for coral reef conservation and management

The massive scale of the 1997-1998 EL Nino-associated coral bleaching event underscores the need for strategies to mitigate biodiversity losses resulting from temperature-induced coral mortality. As baseline sea surface temperatures continue to rise, climate change may represent the single greatest threat to coral reefs worldwide. In response, one strategy might be to identify (1) specific reef areas where natural environmental conditions are likely to result in low or negligible temperature-related bleaching and mortality (i.e., areas of natural resistance to bleaching) and (2) reef areas where environmental conditions are likely to result in maximum recovery of reef communities after bleaching mortality has occurred (i.e., areas of natural community resilience). These target areas, where environmental conditions appear to boost resistance and resilience during and after large-scale bleaching events, could then be incorporated into strategic networks of marine protected areas designed to maximize conservation of global coral reef biodiversity. Based on evidence from the literature and systematically compiled observations from researchers in the field, this paper identifies likely environmental correlates of resistance and resilience to coral bleaching, including factors that reduce temperature stress, enhance water movement, decrease light stress, correlate with physiological tolerance, and provide physical or biological enhancement of recovery potential. As a tool for identifying reef areas that are likely to be most robust in the face of continuing climate change and for determining priority areas for reducing direct anthropogenic impacts, this information has important implications for coral reef conservation and management.