St. Croix, U.S. Virgin Islands—Seafloor elevation change in Maui, St. Croix, St. Thomas, and the Florida Keys

Coral reefs serve as natural barriers that protect adjacent shorelines from coastal hazards such as storms, waves and erosion but projections indicate global degradation of coral reefs due to anthropogenic impacts and climate change will cause a transition to net erosion by mid-century. The U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center conducted research to quantify the combined effect of all constructive and destructive processes on modern coral reef ecosystems by measuring regional-scale changes in seafloor elevation. USGS staff assessed five coral reef ecosystems in the Atlantic Ocean (Upper and Lower Florida Keys), Caribbean Sea (U.S. Virgin Islands: Saint Thomas and Buck Island, St. Croix), and Pacific Ocean (Maui, Hawaii), including both coral-dominated and adjacent, non-coral dominated habitats. Scientists used historical bathymetric data from the 1930s to 1980s and contemporary light detection and ranging (lidar) digital elevation models (DEMs) from the late 1990s to 2000s to calculate changes in seafloor elevation for each study site over time periods reflecting low to high anthropogenic impacts. STC_ElevationChange.zip contains the location, elevation, and elevation change data for Buck Island-St.Croix, U.S. Virgin Islands. Using these changes in elevation, further analysis was done to calculate corresponding changes in seafloor volume for all study areas and habitat types within each site.