Project Methods
Developing the Habitat Classification Scheme
A hierarchical classification scheme was created to define and delineate habitats. The classification scheme was influenced by many factors including: requests from the management community, NOS's coral reef mapping experience in the Florida Keys and Caribbean, existing classification schemes for the Pacific and Hawaiian Islands (Holthus and Maragos 1995; Gulko 1998; Allee et al. unpublished), other coral reef systems (Kruer 1995; Reid and Kruer 1998; Lindeman et al. 1998; Sheppard et al. 1998; Vierros 1997; Chauvaud et al. 1998; Florida Fish and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; Kendall et al. 2001), quantitative habitat data for the Hawaiian Islands, the minimum mapping unit (MMU - 1 acre for visual photointerpretation), and analysis of the spatial and spectral limitations of aerial photography and hyperspectral imagery.
The
hierarchical scheme allows users to expand or collapse the thematic
detail of the resulting map to suit their needs. This is an important
aspect of the scheme as it will provide a "common language" to compare
and contrast digital maps developed from complementary remote sensing
platforms. Furthermore, it is encouraged that additional hierarchical
categories be added in the resulting geographic information system
by users with more detailed knowledge or data for specific areas.
For example, habitat polygons smaller than the MMU can be delineated,
such as reef holes found in parts of the Hawaiian Islands, or habitat
polygons delineated as colonized pavement using this scheme could
be further attributed with health information (i.e., bleached, percent
live cover) or species composition (i.e., Porites, Montipora).
The initial classification scheme was developed through a series of workshops with managers, academics and other local experts in the Hawaiian Islands. Modifications were made throughout the development process based upon feedback provided by workshop participants and other contributors. Additional modifications were made during the mapping process to ensure that each category definition reflected the intended habitats and zones encountered in the field as accurately as possible.