Theme section on “Mesophotic Coral Ecosystems: Characterization, Ecology, and Management”

Abstract

Mesophotic coral ecosystems (MCEs) are characterized by the presence of light-dependent corals and associated communities that are typically found at depths ranging from 30 to 40 m and extending to over 150 m in tropical and subtropical regions. The dominant communities providing structural habitat in the mesophotic zone can be comprised of coral, sponge, and algal species. Because working in this depth range is constrained by traditional SCUBA limits, less is known about corals and associated organisms there compared to shallower coral communities. Following the first-ever gathering of international scientists to review and discuss existing knowledge of MCEs, this issue focuses on the ecological characterization, geomorphology, and concept of MCEs as refugia for shallow-water populations. The review and research papers comprising this special issue reflect the current scientific understanding of these ecosystems and the underlying mechanisms that regulate them, as well as potential resource management implications. It is important to understand the value and role of mesophotic coral ecosystems in tropical and subtropical regions as these areas face increasing environmental change and human impacts Keywords Mesophotic coral ecosystem Á Biodiversity Á Geomorphology Á Connectivity Á Community structure Á Resource management Mesophotic coral ecosystem workshopOn 12-15 July 2008, a scientific workshop was held in Jupiter, Florida, to identify critical research and resource management needs for mesophotic coral ecosystems

Sexual reproduction in octocorals

“…These often overlooked historical descriptions remain a primary source of published information for many deep-water octocoral species. However, with the overall growth in coral reef research providing data on coral reef species and the recent focuses on mesophotic and deep water habitats, there have now been sufficient studies to support an overview of octocoral reproductive biology (Lumsden et al 2007, Hinderstein et al 2010.…”

Efficient light harvesting in deep-water zooxanthellate corals

“…While typically studied within the depth range of recreational SCUBA diving (< 40 m), light-dependent coral reef ecosystems extend far below these depths (Hinderstein et al 2010). In clear oligotrophic waters, zooxanthellate corals can form large aggregations below 100 m, with individual colonies growing at depths >150 m (Maragos & Jokiel 1986, Kahng & Maragos 2006, Kahng & Kelley 2007.…”

Variability in mesophotic coral reef communities along the Great Barrier Reef, Australia

“…However, the effect of these variables on MCE community structure remains poorly understood, particularly in the vastly understudied MCEs of the Indo-Pacific (Hinderstein et al 2010, Kahng et al 2010. Variations in physical water properties -such as wave energy, water clarity, productivity, and sedimentation -both across and along the GBR shelf have been correlated with changes in community composition of shallow-water reef taxa including corals (Done 1982) and octocorals (Dinesen 1983, Fabricius & De'ath 2008.…”