The deep fore reef slope of Osprey Reef has been surveyed by direct observation by the use of the research submersible SP350 to a depth of 240 m. Submersible dives at three sites indicated a very steep, to almost vertical fore reef slope with numerous ledges and overhangs. Evidence of subaerial erosion and bare reef rock substratum have been observed at depths below 100 m. The epibenthos is characterized by a dominance of encrusting coralline algae and octocorals on the vertical walls between 20 and 80 m. Substratum cover decreases rapidly below 80 m. with only very few scleractinian corals extending to 100 m. The deeper part of the fore reef revealed only a few antipatharians and gorgonaceans. The major factors controlling the distribution o f sessile organisms on the deep fore reef slope are discussed.

Depth range
0- 240 m

Mesophotic “mentions”
1 x (total of 3374 words)

Classification
* Presents original data
* Focused on 'mesophotic' depth range
* Focused on 'mesophotic coral ecosystem'

Fields
Ecology
Geomorphology
Community structure

Focusgroups
Overall benthic (groups)
Scleractinia (Hard Corals)
Fishes

Locations
Australia - Coral Sea

Platforms
Manned Submersible
SCUBA (open-circuit or unspecified)