Elkhorn Coral

ground condition

Data access URL

Bathymetry source: NGDC Coastal Relief Model for Puerto Rico & Virgin Islands (Vol. 9), and Florida and Eastern Gulf of Mexico (Vol. 3). Using ESRI's ArcGIS ArcMap software and Spatial Analyst extension, ran the 'Surface Analysis' tool, 'Contour'. Set contour interval to 30 (CRM is in tenths of meters). The contour line was a bit blocky, so smoothed using ET GeoWizard (3rd party software) to smooth the contour using Bezier Curve smoothing algorithm with default settings (5 for smoothness) for the Caribbean and 10 for smoothing setting for Florida, and then cleaned. Converted the polyline to a polygon. Deleted very small polygons/ or polys for depths +/- 1m.

The process of creating an outer boundary using the gridded bathymetry data produced polygons with very dense veritices. ET GeoWizards (3rd party software) was used to generalize the polygons, using the Douglas-Poiker algorithm. A generalize tolerance of .00001 arc seconds was assigned.

Used detailed shoreline for Puerto Rico and the Virgin Islands from NOAA National Centers for Coastal Ocean Science (NCCOS), by selecting 'Land' and 'mangrove' polygons. Used NOAA medium resolution vector shoreline for Florida to create land polygon. Erased the bathymetry polygons with the land/mangrove polygons . For Florida shoreline, or shoreward side of the critical habitat polygon, used Florida Fish & Wildlife Commission (FWC) for nearshore bathymetry (digitized from NOAA nautical charts) for the 6 ft depth to Government Cut, FWC 1:24,000 scale shoreline, COLREG lines, and intercouncil boundary between South Atlantic and Gulf of Mexico Fishery Management Councils at the mouths of bays and inlets, and information from the U.S. Navy for exclusions. The polygon that included to the 30 meter contour was erased with the appropriate data for the shoreward side.

Updated bathymetry East of St. John was added to the critical habitat layer.

Repaired geometry errors in Florida area feature only.