MCEs can form on high-angle continental and insular slopes as illustrated here, or on low-angle outer insular shelves and on the tops of
submerged banks. Decreased light penetration rather than reduced temperature appears to be the primary limiting factor controlling the depth
distribution of MCEs at most locations.
30 m
90 m
150 m
60 m
180 m
120 m
Shallow surface reefs
“Upper”mesophotic coral ecosystems
“Lower”mesophotic coral ecosystems
Approx. limit of most recreational scuba diving
Shallow reefs dominated by scleractinian corals
Decrease in light intensity
Lower range for most research diving with mixed-gas equipment
Upper range for most research using deep-diving vehicles
Depth in metres
The mesophotic coral ecosystem
Source: Richard Pyle, unpublished data.