UC San Diego

Coral reef ecosystems are under threat from a myriad of stressors, ranging from direct human stress (e.g. fishing) to global climate change (e.g. warming sea surface temperatures). Climate change will shift the fundamental habitats in which coral reefs reside. To better understand coral reef survival likelihood in future climate scenarios, these habitats are assessed in both present and future conditions. Classification of Pacific coral reefs by physico-chemical environment shows that there is in fact great complexity in coral reef habitat. Sea surface temperatures, aragonite saturation state, storm frequency, nutrient levels, and current speeds are all critical factors in determining physico-chemical habitat. A case study in the Hawaiian Islands indicates that these habitats are in part reflected in coral reef ecology, although it is difficult to tease apart the effects of ocean environment considering the myriad of human stressors to coral reefs. Future coral reef habitats are assessed for two climate change scenarios. Non-uniform habitat constriction is found worldwide. Reefs in the Caribbean Sea are particularly vulnerable to climate change. Reefs in the Indian Ocean are currently experiencing conditions quite similar to projected conditions worldwide, and are ideal candidate regions to select corals for re-wilding and translocation efforts. Finally, case study of regional oceanography in French Polynesia provides further insights into downscaling global projections to individual islands