Mesophotic gorgonian corals comprise a polyphyletic group of octocorals mostly with a proteinaceous branch- ing axial skeleton. Dense assemblages of gorgonian corals usually dominate the seascape in mesophotic coral ecosystems (MCEs). In this chapter, we review the mesophotic gorgonian coral biodiversity, followed by a synthesis of the ecological implications of inhabiting this environment, as well as the threats that these communities face. MCEs include ~87 gorgonian corals genera distributed worldwide, where the Indo-Pacific (65) is almost twice as diverse as the Caribbean and Gulf of Mexico (37) and Brazil (23), whereas the Tropical Eastern Pacific has only eight genera. We discuss several predictions on the nature of mesophotic gorgonian corals in areas such as microbial endosymbiosis to understand the health, ecology, and evolution of these assemblages. A notable colonization of shallow-water species into MCEs in the Caribbean suggests that colonizing deeper environments promotes ecological divergence. MCEs are not immune to the influence of natural events such as tropical storms and/or anthropogenic encroachment from coastal development, pollution, global climate change, ocean acidification, and overfishing; yet, gorgonian corals in general appear resilient to many of these threats.

Depth range
30- 200 m

Mesophotic “mentions”
100 x (total of 6899 words)

Classification
* Focused on 'mesophotic' depth range
* Focused on 'mesophotic coral ecosystem'

Fields
Biodiversity
Climate Change
Community structure
Connectivity
Disturbances
Ecology
Evolution
Physiology
Reproduction

Focusgroups
Octocorallia (Soft Corals)

Locations
Australia - Great Barrier Reef
Brazil - Eastern Brazil
Brazil - Fernando Noronha
Brazil - St Peter and St Paul Archipelago
Brazil - Trindade and Martin Vaz
Colombia - Caribbean Sea
Mexico - Baja California
Mexico - Caribbean Sea
Mexico - Gulf of Mexico
Micronesia - Caroline Islands (Pohnpei)
Micronesia - Marshall Islands
Papua New Guinea
Puerto Rico
Republic of Palau
USA - Gulf of Mexico
USA - Hawaii
Venezuela - Caribbean Sea

Platforms
Dredging / trawling
Fishing
Manned Submersible
Rebreather
Remotely Operated Vehicle (ROV)
SCUBA (open-circuit or unspecified)