benthic classes (Harborne et al. 2006). Hyperspectral data is required to support
this relatively high number of classes.
For a practitioner, the main decision to be made is the number of habitat classes
to aim to identify and to establish an appropriate and realistic classification scheme
Key for (a)
Massive and encrusting corals
Bare bedrock pavement
Acropora palmata reef
Dictyota on pavement
Montastraea reef
Thalassia with Lobophora
Sparse corals and low algal cover
Sparse seagrass
Sparse corals and high algal cover
Medium density seagrass
Rubble
Dense seagrass
Turf algae and Millepora
Sand
Sand with sparse gorgonians
Sand with sparse algae
Dense gorgonians on bedrock
Sand with calcerous green algae
Bedrock, fleshy and calcerous a lgae
No data
Key for (b)
beta diversity
4
(a)
(b)
3
2
1
0
Fig. 4.5 CASI derived benthic maps of St. John in the U.S. Virgin Islands: a 19-class habitat
map and b beta diversity. Map width is 15.7 km (Harborne et al. 2006)
96
J. D. Hedley