Geodataset Name:       CORALT
Geodataset Type:       SHAPEFILE
Geodataset Feature:    POLYGON
This dataset contains the locations of various types of coral platforms along the coastline of the Florida Keys. This data layer is an update of CORALT released with FGDL Version 2003.
DATA SOURCE(S):                    Florida Marine Research Institute (FMRI)
DATE OF AUTOMATION OF SOURCE:      Source - 1992  Automated - 2001
GEODATASET EXTENT:                 The Florida Keys


Datafile Name: CORALT.DBF
4 OID ---
0 Geometry ---
19 Number 8
19 Number 8
5 String ---
1 Number ---
50 String ---


Item Description
FID Internal feature number.

SHAPE Feature geometry.

AREA Area of the polygon in square meters

PERIMETER Perimeter of the polygons in meters

A_CODE Alphabetic code used to describe bottom type. Benthics Codes:
CPSS = Reef Containing Shallow Spur And Groove

CPSD = Reef Containing Drowned Spur And Groove

CPR = Remnant Reef

CB = Back Reef

CR = Reef Rubble

FKNMS Indicates whether a polygon is part of the Florida Keys National Marine Sanctuary (FKNMS)
1 = Part of FKNMS

0 = Not a part of FKNMS


Attribute accuracy is relied on the integrity of the attribute information within the originl data layer

This data set contains polygons representing 24 bottom-types within the Florida Keys, Biscayne Bay, and Florida Bay. Three modifiers are also used to describe special cases: Banks, dredged areas, restoration areas. Items containing generic groupings (corals, patchy seagrass, continuous seagrass, etc.) have been added to allow the user to draw/query data on a greater scale.

A note concerning data scale:

Scale is an important factor in data usage. Certain scale 
datasetsare not suitable for some project, analysis, or
modelling purposes. Please be sure you are using the best
available data.

1:24000 scale datasets are recommended for projects that 
are at the county level.

1:24000 data should NOT be used for high accuracy base 
mapping such as property parcel boundaries.

1:100000 scale datasets are recommended for projects that 
are at the multi-county or regional level.

1:250000 scale datasets are recommended for projects that 
are at the regional or state level or larger.

Vector datasets with no defined scale or accuracy should 
be considered suspect. Make sure you are familiar with 
your data before using it for projects or analyses. Every 
effort has been made to supply the user with data 
documentation. For additional information, see the 
References sectionand the Data Source Contact section of 
this documentation. For more information regarding scale 
and accuracy, see our web pages at:

For more information contact the FWC-FMRI (Florida Fish 
and Wildlife Conservation Commission-Florida Marine Research 
Institute) GIS data librarian at gislibrarian@fwc.state.fl.us

The platform reefs in this data were selected out from FMRI's South Florida 
Benthics 1992 dataset. This data was generated by FMRI and NOAA staff through 
1:48,000 aerial photographs and digitally compiled.
Process Date: 1992

Data generated by FMRI and NOAA staff, along with ecologists contracted by NOAA and FMRI. The aerial photographs used in producing the maps were taken and digitally compiled by NOAA's NGS staff. Contracted ecologists and FMRI staff developed the classification scheme. FKNMS staff provided support for the photo interpretation, delineation, and ground-truthing activities and for reviewing the benthic classifications. NGS staff digitally compiled the photographic information. Staff from SEA converted the NGS digital files into a Geographic Information System (GIS) and then performed QA/QC on those files. Staff from both FMRI and ORCA designed and produced the atlas. Aerial Photography Natural-color aerial photographs of the Florida Keys region were taken by NOAA's Remote Sensing Division during flights made from December 1991 through April 1992. A Wild RC-30 camera mounted in a Cessna Citation II Fanjet aircraft was used. The source photography had a nominal photo scale of 1:48,000 (1 cm = 480 m). Each photograph covered an area of approximately 160 km2. An 80% endlap and 60% sidelap of adjacent photographs ensured that coverage would be complete and that an adequate number of reference locations would be present for photogrammetric measurements. Approximately 450 photos provided monoscopic coverage and were used to delineate benthic habitats. Establishing a Habitat-Classification Scheme Two recognized ecologists, both with local knowledge of the Florida Keys and extensive expertise in marine habitats, along with FMRI staff, developed the hierarchical classification scheme used in this atlas. The habitat-classification scheme is composed of 24 classes of benthic communities in 4 major habitat categories: corals, seagrasses, hardbottom, and bare substrate. Dredge zones, banks, and restoration areas located within these communities are also denoted. Photointerpretation Photos were interpreted by the wo ecologists and FMRI staff. They determined and then delineated the types of benthic habitats found in the aerial photos. The minimum habitat area delineated was 0.5 ha. However, patch reefs (herein considered part of the coral reef benthic habitat) of less than 0.5 ha were delineated as points. Ground truthing was conducted to verify that benthic habitats were properly identified on the aerial photographs. Researchers were able to ground truth most benthic communities while snorkeling; scuba gear enabled them to ground truth for those communities located in deeper or turbid waters. Field information about the benthic habitat and site GPS locations was recorded. The ecologists and FMRI staff reviewed photos for content and accuracy and then sent them to NOAA for digital compilation. Digital Compilation of Aerial Photographs NGS cartographers inspected each photograph for completeness of delineations, photo discrepancies, and areas of turbidity. Cartographers used a stereographic analytical plotter with NOAA's in-house software to digitize and label the benthic communities and shoreline features seen on the aerial photos. In many cases, the cartographers were able to provide additional detail because of the three-dimensional views permitted by the analytical plotter. The compiled data were checked by NGS staff. Quality Control - Data were reviewed in three phases: 1) a review of digital data to ensure line and attribute completeness, 2) a comparison between the 1:48,000-scale maps of the compiled data and the original source photos, and 3) a comparison between the 1:24,000-scale maps of the compiled data and the original delineated photos to determine the positional accuracy of polygonal shapes and attributes. Positional Accuracy Standards - Aerial photographs used to generate the digital data for the maps in this atlas were taken between December 1991 and April of 1992. Thus, the atlas represents the distribution of benthic habitats in the Keys over this time period. The horizontal accuracy of well-defined points (clearly identifiable, immobile objects such as the tops of radio towers or the corners of wharves) is within 2 m. The horizontal accuracy of continuous data (e.g., benthic habitats) ranges from 5 to 10 m, depending on the habitat class. Certain benthic features, such as patch reefs and spur-and-groove reefs, have a horizontal accuracy of 5 m. These habitats are composed of massive rock and coral formations that are stable in position over time and are resistant to all but the most powerful physical forces. Coral reefs, once established, tend to remain for decades or centuries. Other habitats-such as seagrass beds, hardbottom communities, and bare substrate-are less stable. These benthic features are positionally accurate to within 10 m. Physical factors such as water currents and hurricanes and biological factors such as seasonal growth and die-off affect the distribution and stability of these benthic habitats along the ocean's floor. Plant densities within seagrass communities may increase or decrease over a period of months or years. Hardbottom habitats may become covered by sediment and then by seagrasses. GIS Data Layers To ensure that the digital data sets in this atlas were geographically and attributionally correct, SEA staff used a series of data-translation and topology-construction steps while incorporating the data into a GIS, a sophisticated computer mapping and analysis software. All the individual GIS digital data sets were then combined to form several regional mosaics. Each region's data set was sent to FMRI for final quality control and assembly. FMRI inspected these data sets to ensure that no errors remained. The regional data sets were then joined together to make an FKNMS-wide, benthic-habitat data set. The resulting data set was inspected one last time, with particular scrutiny paid to the regions of overlap, where errors would most likely occur. The delineated aerial photos were referred to at every step of this process. Process Date: 20010000
GeoPlan downloaded this data in shapefile format from the FMRI FTP site: ftp.floridamarine.org/users/ism/datareq/ and projected to FGDL Albers HPGN. When received, the data was in Geographic projection, Datum: NAD 83, Spheroid: GRS1980. -Reprojected data to FGDL Albers HPGN -Renamed shapefile from platformreef_bisbaykeys_poly to CORALT -Deleted OBJECTID, CORALPLAT_, AND CORALPLAT_ID fields from attribute table -Deleted SHAPE_AREA and SHAPE_LEN from attribute table -Created DESCRIPT field based on A_CODE Process Date: 20030000

Projection                          ALBERS
Datum                               HPGN
Units                               METERS
Spheroid                            GRS1980
1st Standard Parallel               24  0  0.000
2nd Standard Parallel               31 30  0.000
Central Meridian                   -84 00  0.000
Latitude of Projection's Origin     24  0  0.000
False Easting (meters)              400000.00000
False Northing (meters)             0.00000


Abbr. Name:


Web site:
Contact Person:
Florida Marine Research Institute
100 8th Ave SE
St. Petersburg, FL
(727) 896-8626

http://www.floridamarine.org/ gislibrarian@fwc.state.fl.us Chris Anderson
Abbr. Name:             FGDL
Address:                Florida Geographic Data Library
                        431 Architecture Building
                        PO Box 115706
                        Gainesville, FL  32611-5706
Web site:               http://www.fgdl.org

Contact FGDL: 

      Technical Support:	        http://www.fgdl.org/fgdlfeed.html
      FGDL Frequently Asked Questions:  http://www.fgdl.org/fgdlfaq.html
      FGDL Mailing Lists:		http://www.fgdl.org/fgdl-l.html
      For FGDL Software:                http://www.fgdl.org/software.html