Project Methods
Developing the Habitat Classification Scheme
A hierarchical classification scheme was used to define and delineate habitats. The classification scheme was influenced by many factors including: requests of the management community, existing classification schemes for coastal ecosystems in Puerto Rico (Kruer, 1995; Reid and Kruer, 1998; Lindeman et al.,1998), the Virgin Islands (Conservation Data Center; Beets et al., 1986; Boulon, 1986), other coral reef systems (Holthus and Maragos, 1995; Shepard et al., 1995; Vierros, 1997; Chauvaud et al., 1998; Florida Fish and Wildlife Conservation Commission, Florida Marine Research Institute and NOAA, 1998; Mumby et al.,1998; NOAA et al., 1998), quantitative habitat data for Puerto Rico and the Virgin Islands, the minimum mapping unit (MMU- 1 acre for visual photointerpretation), and analysis of the spatial and spectral limitations of the scanned aerial photographs.
The scheme is hierarchical to allow users to expand or collapse the detail of the resulting map to suit their needs. Furthermore, it is encouraged that additional hierarchical categories be added in the GIS by users with more detailed knowledge or data for specific areas. For example, habitat polygons delineated as continuous seagrass using this scheme could be further categorized by standing crop information (low, medium, or high shoot density) or species composition (Thalassia, Syringodium).