Reef-building corals occur across large depth ranges in part due to the physiological flexibility of the symbiosis between coral animal hosts and the dinoflagellate algae within their tissues. Some coral species inhabit both shallow and upper mesophotic reefs between the surface and 60 meters depth (200 feet).

Given the various impacts affecting shallow coral populations, most notably climate change induced coral bleaching, there is great interest in the potential role of lower-light, mesophotic (‘middle light’) coral ecosystems in reef resilience. Mesophotic coral species may be able to avoid anthropogenic impacts (e.g. elevated seawater temperatures) due to their location on deeper reefs, and/or mesophotic reefs may contribute to coral resilience by maintaining local diversity and ecosystem function. This project will test the thermal thresholds and investigate the climate change resilience of depth specialists, i.e., corals that are predominantly found at mesophotic depths.