6.2.2 Benthic Habitat Mapping
An important goal of benthic habitat mapping is to help resource managers make
informed and ecologically relevant decisions, thereby supporting the process of
ecosystem-based management and marine spatial planning. Benthic habitat maps
have been used to: (1) understand and predict the spatial distribution of resources,
(2) detect environmental change, (3) design monitoring sampling strategies, and
(4) delineate zones and assess the efficacy of marine protected areas (Ward et al.
1999; Friedlander et al. 2007a, b; Pittman et al. 2011a, b). LiDAR supports benthic
habitat mapping by acquiring continuous information about the depth and structural properties of the seafloor in depths reaching 60–70 m under optimal conditions (Stumpf et al. 2003). Seafloor habitats are differentiated from each other
based on their geomorphological structure (e.g., their physical composition) and
biological cover (i.e., the types and abundance of sessile organisms that colonize
those structures). The three-dimensional detail provided by LiDAR offers the
potential to develop highly accurate benthic habitat maps even in the absence of
other remote sensing data types. In locations with overlapping multispectral or
hyperspectral imagery and LiDAR data sets, combining LiDAR derived digital
elevation models (DEMs) with spectral data enhances the overall accuracy of the
derived benthic habitat maps (Chust et al. 2010; see Chap. 7). In Hawaii, Conger
et al. (2006) used LiDAR bathymetry from the USACE SHOALS system (U.S.
Army Corps of Engineers Scanning Hydrographic Operational Airborne LiDAR
Survey; Irish and Lillycrop 1999; Irish et al. 2000) in conjunction with multispectral QuickBird imagery to develop a simple technique to decorrelate remote
sensing color band data from depth in areas of shallow water. The method produced pseudo-color bands that were suitable for direct knowledge-based interpretation, as well as for calibration to absolute seafloor reflectance.
Seamless land topography and marine bathymetry digital elevation models are
now becoming available (see Chap. 5) and provide an opportunity for the development of models that quantify land-sea interactions, such as runoff impacts to
nearshore coral reef ecosystems. Furthermore, combined bathymetric and topographic LiDAR systems can survey land and seafloor simultaneously, a useful
capability for mapping land adjacent to coral reef ecosystems or where emergent
features such as cays and intertidal flats exist. LiDAR provides a three-dimensional representation of the seafloor, which has important utility in identifying and
mapping habitat types with differing geomorphological characteristics and varying
levels of topographic complexity. Three-dimensional surface features are also
important in predicting species distribution patterns across coral reef ecosystems
(Pittman et al. 2009; Pittman and Brown 2011; see Sect. 6.3.2).
The Experimental Advanced Airborne Research LiDAR (EAARL) (Wright and
Brock 2002) developed by the National Aeronautics and Space Administration
(NASA) and U.S. Geological Survey (USGS) was used to collect 1 9 1 m
bathymetry for a broad swath of the northern Florida reef tract to map stony coral
reefs in Biscayne National Park (Brock et al. 2006). Rugosity, a measure of surface
6 LiDAR Applications
149
An important goal of benthic habitat mapping is to help resource managers make
informed and ecologically relevant decisions, thereby supporting the process of
ecosystem-based management and marine spatial planning. Benthic habitat maps
have been used to: (1) understand and predict the spatial distribution of resources,
(2) detect environmental change, (3) design monitoring sampling strategies, and
(4) delineate zones and assess the efficacy of marine protected areas (Ward et al.
1999; Friedlander et al. 2007a, b; Pittman et al. 2011a, b). LiDAR supports benthic
habitat mapping by acquiring continuous information about the depth and structural properties of the seafloor in depths reaching 60–70 m under optimal conditions (Stumpf et al. 2003). Seafloor habitats are differentiated from each other
based on their geomorphological structure (e.g., their physical composition) and
biological cover (i.e., the types and abundance of sessile organisms that colonize
those structures). The three-dimensional detail provided by LiDAR offers the
potential to develop highly accurate benthic habitat maps even in the absence of
other remote sensing data types. In locations with overlapping multispectral or
hyperspectral imagery and LiDAR data sets, combining LiDAR derived digital
elevation models (DEMs) with spectral data enhances the overall accuracy of the
derived benthic habitat maps (Chust et al. 2010; see Chap. 7). In Hawaii, Conger
et al. (2006) used LiDAR bathymetry from the USACE SHOALS system (U.S.
Army Corps of Engineers Scanning Hydrographic Operational Airborne LiDAR
Survey; Irish and Lillycrop 1999; Irish et al. 2000) in conjunction with multispectral QuickBird imagery to develop a simple technique to decorrelate remote
sensing color band data from depth in areas of shallow water. The method produced pseudo-color bands that were suitable for direct knowledge-based interpretation, as well as for calibration to absolute seafloor reflectance.
Seamless land topography and marine bathymetry digital elevation models are
now becoming available (see Chap. 5) and provide an opportunity for the development of models that quantify land-sea interactions, such as runoff impacts to
nearshore coral reef ecosystems. Furthermore, combined bathymetric and topographic LiDAR systems can survey land and seafloor simultaneously, a useful
capability for mapping land adjacent to coral reef ecosystems or where emergent
features such as cays and intertidal flats exist. LiDAR provides a three-dimensional representation of the seafloor, which has important utility in identifying and
mapping habitat types with differing geomorphological characteristics and varying
levels of topographic complexity. Three-dimensional surface features are also
important in predicting species distribution patterns across coral reef ecosystems
(Pittman et al. 2009; Pittman and Brown 2011; see Sect. 6.3.2).
The Experimental Advanced Airborne Research LiDAR (EAARL) (Wright and
Brock 2002) developed by the National Aeronautics and Space Administration
(NASA) and U.S. Geological Survey (USGS) was used to collect 1 9 1 m
bathymetry for a broad swath of the northern Florida reef tract to map stony coral
reefs in Biscayne National Park (Brock et al. 2006). Rugosity, a measure of surface
6 LiDAR Applications
149