This book summarizes what is known about mesophotic coral ecosystems (MCEs) geographically and by major taxa. MCEs are characterized by light-dependent corals and associated communities typically found at depths ranging from 30-40 m. and extending to over 150 m. in tropical and subtropical ecosystems. They are populated with organisms typically associated with shallow coral reefs, such as macroalgae, corals, sponges, and fishes, as well as specialist species unique to mesophotic depths. During the past decade, there has been an increasing scientific and management interest in MCEs expressed by the exponential increase in the number of publications studying this unique environment. Despite their close proximity to well-studied shallow reefs, and the growing evidence of their importance, our scientific knowledge of MCEs is still in its early stages. The topics covered in the book include: regional variation in MCEs; similarities and differences between mesophotic and shallow reef taxa, biotic and abiotic conditions, biodiversity, ecology, geomorphology, and geology; potential connectivity between MCEs and shallow reefs; MCE disturbances, conservation, and management challenges; and new technologies, key research questions/knowledge gaps, priorities, and future directions in MCE research.

This book documents and examines the state of health of coral reefs in the eastern tropical Pacific region. It touches on the occurrence of coral reefs in the waters of surrounding countries, and it explores their biogeography, biodiversity and condition relative to the El Niño southern oscillation and human impacts. Additionally contained within is a field that presents information on many of the species presented in the preceding chapters.