Modeling Seafloor Structural Complexity Completed
This effort focused on understanding the patterns and scalability of roughness and topographic complexity of marine habitats, such as coral reefs.
Quantifying Seafloor Topographic Complexity
Topographic complexity (TC) is an important habitat characteristic that encompasses the three-dimensional intricacy of structural components. In aquatic habitats, topographic complexity influences a number of ecological and environmental aspects, such as regulating species richness, providing refuge from predators and physical stresses (e.g., light level, temperature, desiccation, and wave action), and presenting secondary growth surfaces. Moreover, these influences occur over multiple spatial scales.
For coral reefs, TC influences a wide range of biological, chemical, and physical aspects, such as water flow and, consequently, nutrient uptake and mass transfer rates, species richness and biomass, and both refuge and larval-settlement space. Because of these impacts, quantifying and mapping the spatial variability in TC is important to understanding the functioning of a coral reef ecosystem.
Effort was focused on developing algorithms for quantifying TC, with emphasis on fractal geometry principles. Studies have been completed for portions of Biscayne National Park and the island of Navassa.
Biscayne National Park
Within sight of Miami, Biscayne National Park lies at the northern extent of the Florida reef tract and occupies a carbonate platform seaward of Hawk Channel. The park encompasses approximately 700 km2, roughly 95% of which is underwater habitat, including numerous patch reefs and a discontinuous series of shelf-edge, bank-barrier reefs along the seaward boundary. Information about this study is available in the Journal of Coastal Research article "A Multiscale Analysis of Coral Reef Topographic Complexity Using Lidar-Derived Bathymetry."
Navassa Island
Navassa Island is located approximately 50 km west of the southwestern tip of Haiti, and is an uninhabited, pear-shaped island 4.64 km2 in area. In 1999, Navassa Island and a 12-mile radius of marine territory were designated as a National Wildlife Refuge under the jurisdiction of the U.S. Fish and Wildlife Service. Information about this study is available in the Geophysical Research Letters article "Topographic complexity and roughness of a tropical benthic seascape" and related USGS Data Series "Fractal Analysis of the Navassa Island Seascape."
Below are research tasks and science projects associated with this research.
Advanced Remote Sensing Methods for Coastal Science and Management
Applications of Coral Fluorescence
Along-Track Reef Imaging System (ATRIS)
Below are publications associated with this project.
Fractal analysis of the Navassa Island seascape
Topographic complexity and roughness of a tropical benthic seascape
A multiscale analysis of coral reef topographic complexity using lidar-derived bathymetry
- Overview
This effort focused on understanding the patterns and scalability of roughness and topographic complexity of marine habitats, such as coral reefs.
Quantifying Seafloor Topographic Complexity
Topographic complexity (TC) is an important habitat characteristic that encompasses the three-dimensional intricacy of structural components. In aquatic habitats, topographic complexity influences a number of ecological and environmental aspects, such as regulating species richness, providing refuge from predators and physical stresses (e.g., light level, temperature, desiccation, and wave action), and presenting secondary growth surfaces. Moreover, these influences occur over multiple spatial scales.
For coral reefs, TC influences a wide range of biological, chemical, and physical aspects, such as water flow and, consequently, nutrient uptake and mass transfer rates, species richness and biomass, and both refuge and larval-settlement space. Because of these impacts, quantifying and mapping the spatial variability in TC is important to understanding the functioning of a coral reef ecosystem.
Effort was focused on developing algorithms for quantifying TC, with emphasis on fractal geometry principles. Studies have been completed for portions of Biscayne National Park and the island of Navassa.
Biscayne National Park
Within sight of Miami, Biscayne National Park lies at the northern extent of the Florida reef tract and occupies a carbonate platform seaward of Hawk Channel. The park encompasses approximately 700 km2, roughly 95% of which is underwater habitat, including numerous patch reefs and a discontinuous series of shelf-edge, bank-barrier reefs along the seaward boundary. Information about this study is available in the Journal of Coastal Research article "A Multiscale Analysis of Coral Reef Topographic Complexity Using Lidar-Derived Bathymetry."
Navassa Island
Navassa Island is located approximately 50 km west of the southwestern tip of Haiti, and is an uninhabited, pear-shaped island 4.64 km2 in area. In 1999, Navassa Island and a 12-mile radius of marine territory were designated as a National Wildlife Refuge under the jurisdiction of the U.S. Fish and Wildlife Service. Information about this study is available in the Geophysical Research Letters article "Topographic complexity and roughness of a tropical benthic seascape" and related USGS Data Series "Fractal Analysis of the Navassa Island Seascape."
- Science
Below are research tasks and science projects associated with this research.
Advanced Remote Sensing Methods for Coastal Science and Management
This project focused on developing algorithms for quantifying benthic habitat complexity from images, modeling the structural complexity of the seafloor, and using fluorescence signatures to classify coral reef habitats.Applications of Coral Fluorescence
Fluorescence is an often overlooked property of reef-building corals that can improve the classification of reef habitats from imagery and provide diagnostic information on corals.Along-Track Reef Imaging System (ATRIS)
ATRIS is a benthic-survey tool that simultaneously acquires geo-located, color, digital images with corresponding water depths. - Publications
Below are publications associated with this project.
Fractal analysis of the Navassa Island seascape
This release provides the numerical results of the fractal analyses discussed in Zawada and others (2010) for the Navassa Island reefscape. The project represents the continuation of a U.S. Geological Survey (USGS) research effort begun in 2006 (Zawada and others, 2006) to understand the patterns and scalability of roughness and topographic complexity from individual corals to complete reefscapes.AuthorsDavid G. ZawadaTopographic complexity and roughness of a tropical benthic seascape
Topographic complexity is a fundamental structural property of benthic marine ecosystems that exists across all scales and affects a multitude of processes. Coral reefs are a prime example, for which this complexity has been found to impact water flow, species diversity, nutrient uptake, and wave-energy dissipation, among other properties. Despite its importance, only limited assessments are availAuthorsDavid G. Zawada, Clifford J. Hearn, Gregory PiniakA multiscale analysis of coral reef topographic complexity using lidar-derived bathymetry
Coral reefs represent one of the most irregular substrates in the marine environment. This roughness or topographic complexity is an important structural characteristic of reef habitats that affects a number of ecological and environmental attributes, including species diversity and water circulation. Little is known about the range of topographic complexity exhibited within a reef or between diffAuthorsD.G. Zawada, J. C. Brock