Abstract: The vast majority of coral reef research has focussed on shallow-water reefs; however recent technological advances have allowed increased access to previously unexplored depths and revealed that zooxanthellate corals regularly occur to depths in excess of 100 m. Furthermore, upper “mesophotic” depths of 30-60 m support a significantly greater proportion of shallow-water coral reef species than commonly appreciated. Many disturbances on coral reefs decline with depth, therefore deep habitats may provide vital refugia for corals and associated species from climate change, storms and human impacts. Despite widespread recognition of the importance of connectivity between coral reefs and adjacent shallow-water ecosystems, such as seagrass and mangrove forests, connectivity between shallow and deep-water coral reefs remains poorly understood. Ultimately, the potential for deep reefs to provide refugia will depend on 1) the depths range affected by disturbance events; 2) the proportion of species whose ranges straddle both shallow and deep-water reefs and 3) whether deep-water populations can provide a source of propagules to re-seed shallow reef habitats. Here, I will provide an overview of current knowledge on deep-water coral reefs from my research, and identify research gaps that must be addressed to provide a more complete view of coral reef ecosystem function across their full depth range. Adopting a broader ecosystem-scale approach that incorporates both deep and shallow reefs around the world would have multiple social, economic and conservation benefits.

Biography: Tom is originally from Sydney and completed a B.Sc (Honours) in Marine Science at the University of Sydney. His honours thesis examined the influence of environmental variation on the distribution of juvenile black marlin off eastern Australia. After spending time travelling and working in the diving industry, Tom moved to Townsville in 2007 to begin his PhD in the School of Earth and Environmental Science at JCU, studying mesophotic coral reefs on the GBR. His major field work comprised a 3-week expedition on board the RV Southern Surveyor, which conducted the first detailed study of the ecology of the Great Barrier Reef outer-shelf. Completing his PhD in 2011, Tom has continued his research on mesophotic coral reefs at the ARC Centre of Excellence for Coral Reef Studies, JCU.