Abstract In Chile, light-dependent benthic taxa have been observed to ~280 m with the presence of zooxanthellate cnidarians forming mesophotic coral ecosystems (MCEs) to depths of at least 120 m at Rapa Nui (Easter Island) and Salas y Gómez. Evidence from dredge samples suggests MCEs in the southeast Pacific once extended along the Salas y Gómez Ridge as far east as ~85° W, but MCEs in Chile were virtually unexplored prior to 2010. Despite providing critical structural habitat for numerous flora and fauna, including commercially important fishes, basic information about their geographic distribution and community structure are lacking. Here, we review the state of knowledge on these communities and present preliminary results from the most recent surveys at Rapa Nui. Surveys at mesophotic depths (30–280 m) have revealed ecosystems dominated by crustose coralline algae with occasional patches of rhodoliths, undiscovered biodiversity, the first reports of wide-ranging Pacific species, and reports of potential new species in multiple taxa including fishes and echinoderms. Preliminary observations suggest fish communities change with depth and time of day, some habitats support commercially important and juvenile fishes, and MCEs and fisheries at Rapa Nui are in decline due to local, artisanal fishing practices. The recent designation of no-take marine parks in Chile may help to conserve these habitats, but additional information is required to support management decisions and future conservation efforts at Rapa Nui, Salas y Gómez, and seamounts within the Chilean Exclusive Economic Zone.

Depth range
30- 280 m

Mesophotic “mentions”
88 x (total of 5709 words)

Classification
* Focused on 'mesophotic coral ecosystem'

Fields
Behavior
Biodiversity
Community structure
Connectivity
Disturbances
Ecology
Long-term monitoring
Management and Conservation
Physiology

Focusgroups
Algae (Macro, Turf and Crustose Coralline)
Crustacea
Fishes
Octocorallia (Soft Corals)
Other invertebrates
Overall benthic (groups)
Scleractinia (Hard Corals)

Locations
Chile - Easter Island

Platforms
Autonomous Underwater Vehicle (AUV)
Dredging / trawling
Fishing
Rebreather
Remotely Operated Vehicle (ROV)
SCUBA (open-circuit or unspecified)