Robert Halley (retired) Ellen Prager (no longer with USGS), 1997, Florida Bay Bottom Types map: USGS Open-File Report OFR 97-526, U.S. Geological Survey, St. Petersburg, FL.Online Links:
Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.00001. Longitudes are given to the nearest 0.00001. Latitude and longitude values are specified in Decimal degrees.
The horizontal datum used is North American Datum of 1983.
The ellipsoid used is Geodetic Reference System 80.
The semi-major axis of the ellipsoid used is 6378137.
The flattening of the ellipsoid used is 1/298.257.
Bank Top Suite - commonly called mud banks and occurring at depths typically less the 0.6 m. These areas are spatially complex environments that are dominated by mud, sand, or, in the western portion of the Bay, gravel.
Open Mud - areas where no significant seagrass growth occurs and other benthic fauna except for algal mats are not apparent. Sediments are predominately carbonate mud with a relatively high organic and water content.
Hardbottom - areas with little or no seagrass cover and only up to 5 cm of sediment overlying the Pleistocene limestone bedrock. Sediments tend to be either lightly muddy carbonate sand or sand, have relatively little organic matter, and low water content.
Sparse Seagrass Cover - area in which greater than 50 percent of the bottom is exposed. Sediments are predominately slightly muddy carbonate sand, sandy mud, or sand and vary form 3 cm to over 2 m in thickness.
Intermediate Seagrass Cover - greater than 50 percent seagrass cover with open areas of exposed sediment on the bottom less that 50 percent. Sediments are dominated by sand and shelly (gravely) carbonate mud from 0.33 m to over 2m thick.
Dense Seagrass Cover - areas where the bottom is completely obscured from view by grass growth. Sediments are muddy sand with a relatively high organic and/or shell content.
Open Sandy Areas - areas that are distinct from hardbottoms in that no significant benthic life is present. Sediments are coarse shelly carbonate sands.
Mixed Bottom Suites - areas of a highly variable bottom type where variations in seagrass density are extreme and open mud areas occur on a seemingly irregular basis. Sediments are coarse shelly carbonate sands.
Data was collected by Robert Halley and Ellen Prager. The original map layout was recreated by Heather Mounts.
561 682-6561 (voice)
drudnic@sfwmd.gov
The purpose of this map is to describe the bottom types found within Florida Bay for use in 1) assessing bottom friction associated with sediment and benthic communities and 2) providing a very general description for other research needs. For these purposes, two descriptors were considered particularly important: density of seagrass cover and sediment texture. Seagrass estimates are visual estimates of the amount of seagrass cover including both number of plants and leaf length. Therefore, seagrass cover may be greater in areas with long leaves than in areas with short blades, even though the number of shoots may be the same. Seagrass cover is a different measure than density (Zieman et al., 1989 or Durako et al., 1996). It is used here to more accurately reflect hydrodynamic influence than the standing crop of seagrass. The use and definitions of dense, intermediate and sparse seagrass cover are similar to those used by Scoffin (1970). This map and associated descriptions are not meant to assess ecologic communities or detail sedimentological facies. The resolution of the map has been selected in an effort to define broad regions for use in modeling efforts. For these purposes, small-scale changes in bottom type (e.g. small seagrass patches) are not delineated.
The site surveys and boat transects were compared with aerial photographs from December 1994 - January 1995 and SPOT satellite imagery from 1987 to produce the map of bottom types for Florida Bay. The map of bottom types was created using CPS3 (Contour Plotting System software) and ArcInfo 7.0.3.
The data were reprojected from UTM ZONE 17, NAD83 to GEOGRAPHIC, NAD83 for SUDS 5/20/02.
The map was created using CPS3 (Contour Plotting System software), ArcInfo7, and AMLs. The coverage was converted to a shapefile to be used on ArcView applications.
Descriptions: The description of the sediment data and use of ArcView assumes the reader has limited knowledge of ArcView 3.2.
sed.apr is a project file that might come in handy to quickly look at the data. Edit the .apr file and search for the pathnames for newsed4 and sedpts97. Change the file names to where the data files are stored.
The sed.avl file contains the shade set for the sed data. In ArcView, add the newsed4 theme, and then bring up the legend editor, legend type-unique value, values field - sedname. Then 'load' the sed.avl, and it will look like the map that Ellen Prager produced.
There is also a layout of the map that looks like what she published (although this layout was recreated for the web site). The newsed.ps postscript file is 8.5 X 11 inches. Or desired portions can be printed from the layout.
Problems bringing this in to Adobe Illustrator to print it were corrected by just changing the mudbank color (removing the stippling) in ArcView.
Person who carried out this activity:
561 682-6561 (voice)
drudnic@sfwmd.gov
Prager, E. J. Halley, R. B., 1999, The influence of seagrass on shell layers and Florida Bay mudbanks: Journal of Coastal Research v. 15, 1151-1162, Coastal Education and Research Foundation (CERF), Fort Lauderdale, FL.
Bosence, D., 1989, Surface sublittoral sediments of Florida Bay: Bulletin of Marine Science 44 (1): 434-453, University of Florida Press, Coral Gables, FL.
Durako, M. J. Hall, M., Hall, J., 1996, The status and trends of seagrass communities in Florida Bay: Florida Bay Science Conference 1996 programs and Abstracts, Florida Sea Grant, Key Largo, FL.
Zieman, J. C. Fourqurean, J. W., Iverson,, 1989, Distribution, abundance, and productivity of seagrass and macroalgae in the Florida Keys: Bulletin of Marine Science 44(1): 292-311, University of Florida Press, Coral Gables, FL.
Fairbridge, R. W., editor, 1996, Encyclopedia of the Earth Sciences: McGraw Hill Book Co., New York, NY.
Scholl, D. W., 1996, Florida Bay: A modern site of limestone formation:.This is part of the following larger work.
Fairbridge, R. W., editor, 1996, Encyclopedia of the Earth Sciences: McGraw Hill Book Co., New York, NY.
Local information was recorded in the Bay using a military style GPS unit - Rockwell Precision Lightweight GPS Receiver PLGR+96 with a precision of +/- 10m.
Over 650 sites in the Bay were located and examined using a small, flat-bottomed boat, high resolution GPS and snorkeling gear
not applicable
Are there legal restrictions on access or use of the data?
- Access_Constraints: none
- Use_Constraints:
- None. However, the resolution of the map has been selected to define broad regions for use in modeling efforts.
727 803-8747 ext 3028 (voice)
727 803-2030 (FAX)
hhenkel@usgs.gov
Florida Bay Bottom Types map
The data have no implied or explicit guarantees
| Data format: | Florida Bay Bottom Types map in UTM, Zone 17 in format ESRI shapefile (version 7.0) Size: 4.4 |
|---|---|
| Network links: |
<http://sofia.usgs.gov/publications/ofr/97-526/> |
| Data format: | Adobe Acrobat pdf (version 5.0) Size: 0.27 |
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| Network links: |
<http://sofia.usgs.gov/publications/ofr/97-526/ofr-97-526-map.pdf> |
| Data format: | JPEG Size: 0.25 |
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| Network links: |
<http://sofia.usgs.gov/publications/ofr/97-526/bottom-types-map.jpg> |
| Data format: | Florida Bay Bottom Types map (geographic projection) in format ESRI shapfile (version 7.0) Size: 3.5 |
|---|---|
| Network links: |
<http://sofia.usgs.gov/publications/ofr/97-526> |
727 803-8747 ext 3028 (voice)
727 803-2030 (FAX)
sofia-metadata@usgs.gov
U.S. Department of the Interior, U.S. Geological Survey
Comments and suggestions? Contact: Heather
Henkel - Webmaster
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