Although remote sensing technology is a useful tool for monitoring shallow (<20 m depth) coral reefs present in clear oligothrophic waters, the large-scale assessment of reefs present in optically-deep waters requires other approaches such as the use of in situ platforms for high-resolution optical and acoustic imaging. Optically-deep waters are those where the upwelling radiance received by the airborne or satellite sensor originates from the water column without any bottom signal contribution. The Seabed autonomous underwater vehicle (AUV) is an ideal platform for mapping and characterizing mesophotic reefs, those present between 30 to about 100 m depth, and for shallow reefs in turbid areas. This AUV was utilized to acquire high-resolution digital images to characterize the geomorphology and dominant benthic components present along two long photo-transects in southwestern Puerto Rico. These quantitative AUV surveys also provide a baseline for future evaluation of change in the deeper coral reef zones, which for most areas of the world, remain largely unknown.

Depth range
27- 130 m

Mesophotic “mentions”
7 x (total of 2014 words)

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

Fields
Geomorphology
Community structure

Focusgroups
Overall benthic (groups)

Locations
Puerto Rico

Platforms
Autonomous Underwater Vehicle (AUV)