Benthic Habitats of the Florida Keys

Metadata for Florida Keys Benthic Habitats digital geography

last updated July 1998

Digital geographies are in geographic coordinates, datum = NAD83, spheroid = GRS1980.

GENERAL INFORMATION
Name:	BENTHIC_G
Title:	FLORIDA KEYS AND BISCAYNE BAY BENTHICS
Library:	BENTHIC
Feature Type:	POLYGON
Geographic Extent:	THE FURTHERMOST WESTERN BOUNDARY OF THE FLORIDA KEYS NATIONAL MARINE SANCTUARY (DRY TORTUGAS) NORTH TO WHERE 215TH STREET NORTHEAST IN DADE COUNTY INTERSECTS BISCAYNE BAY
Creation Date:	UNKNOWN
Projection:	GEOGRAPHIC COORDINATES, DECIMAL DEGREES, NAD83
Precision:	SINGLE
Datum:	NORTH AMERICAN DATUM OF 1983
Accuracy:	ACCURACY OF DISCRETE POINTS IS WITHIN TWO METERS. SHORELINE AND REEF HABITATS HAVE AN ACCURACY OF FIVER METERS. SEAGRASSES AND OTHER LESS RESISTANT HABITATS HAVE AN ACCURACY OF 10 METERS.
Purpose:	TO VISUALLY REPRESENT GEOSPATIAL DATA.
Description - Abstract:	POLYGON GEOGRAPHY TO VISUALLY REPRESENT THE BENTHIC HABITATS GEOSPATIAL DATA OF SOUTH FLORIDA.
Report last modified:	19980521

DATA SOURCE INFORMATION
Organization:	FISH and WILDLIFE RESEARCH INSTITUTE
Contact:	KATHLEEN O'KEIFE
Address:	100 8TH AVENUE S.E., ST. PETERSBURG, FL 33701-5095
Phone Number:	727/8968626
Electronic mail:	Kathleen.OKeife@MyFWC.com
Scale:	UNKNOWN
Projection:	GEOGRAPHIC COORDINATES, DECIMAL DEGREES, NAD83
Precision:	SINGLE
Datum:	NORTH AMERICAN DATUM OF 1983
Accuracy:	ACCURACY OF DISCRETE POINTS IS WITHIN TWO METERS. SHORELINE AND REEF HABITATS HAVE AN ACCURACY OF FIVER METERS. SEAGRASSES AND OTHER LESS RESISTANT HABITATS HAVE AN ACCURACY OF 10 METERS.
Source Format:	UNKNOWN.

DISTRIBUTION INFORMATION
QA/QC Status:	COMPLETE
Distribution Status:	AVAILABLE
Data Format:	ARC/INFO EXPORT FILE (.e00), ARCVIEW SHAPEFILE
FWRI Contact:	KATHLEEN O'KEIFE
FWRI Address:	FLORIDA FISH AND WILDLIFE CONSERVATION COMMISSION, FISH AND WILDLIFE RESEARCH INSTITUTE, 100 8TH AVENUE S.E., ST. PETERSBURG, FL 33701-5095
FWRI Phone:	727/896-8626

Minimum mapping unit = 0.4 hectare (1 acre) for all habitat. Patch reefs may be <0.5 ha.

DATA DICTIONARY
Polygon attributes used in Benthic Habitat geography
01. Item: A_CODE	ALPHA CODE FOR THE BENTHIC HABITATS
	Type: Character
	Length: 5
	Decimals: 0
	Format: N/A
	Mandatory: N
	Default Values: N/A
	Item Values:
	BM	CARBONATE MUD
	BMd	CARBONATE MUD; DREDGED/EXCAVATED
	BO	ORGANIC MUD
	BS	CARBONATE SAND
	BSb	CARBONATE SAND; BANKS
	BSd	CARBONATE SAND; DREDGE/EXCAVATED
	BUd	BOTTOM UNKNOWN; DREDGED/EXCAVATED
	CB	BACK REEF
	CPA	AGGREGATED PATCH REEFS
	CPB	CORAL PATCHES IN BARE SAND
	CPH	HALO
	CPI	INDIVIDUAL PATCH REEF
	CPIH	INDIVIDUAL PATCH REEF AND HALO
	CPR	REMNANT REEF
	CPSD	REEF CONTAINING DROWNED SPUR AND GROOVE
	CPSS	REEF CONTAINING SHALLOW SPUR AND GROOVE
	CR	REEF RUBBLE
	h2o	UNCLASSIFIED OCEANIC WATER
	HC	SOFT CORAL,SPONGES,ALGAE
	HCb	SOFT CORAL,SPONGES,ALGAE; BANKS
	HS	HARDBOTTOM WITH PERCEPTIBLE SEAGRASS
	HSb	HARDBOTTOM WITH PERCEPTIBLE SEAGRASS; BANKS
	HSd	HARDBOTTOM WITH PERCEPTIBLE SEAGRASS; DREDGRED/EXCAVATED
	InW	UNCLASSIFIED INLAND WATER
	LAND	LAND
	SD	MODERATE TO DENSE, CONTINUOUS BEDS
	SDb	MODERATE TO DENSE, CONTINUOUS BEDS; BANKS
	SDd	MODERATE TO DENSE, CONTIUOUS BEDS; DREDGED/EXCAVATED
	SDdr	MODERATE TO DENSE, CONTIUOUS BEDS; DREDGED/EXCAVATED; RESTORATION
	SDr	MODERATE TO DENSE, CONTIUOUS BEDS; RESTORATION
	SDB	MODERATE TO DENSE, CONTIUOUS BEDS WITH BLOWOUTS
	SDBb	MODERATE TO DENSE, CONTINUOUS BEDS WITH BLOWOUTS; BANKS
	SDBd	MODERATE TO DENSE, CONTIUOUS BEDS WITH BLOWOUTS; DREDGED/EXCAVATED/RESTORATION
	SDBdr	MODERATE TO DENSE, CONTIUOUS BEDS; DREDGED/EXCAVATED; RESTORATION
	SDBr	MODERATE TO DENSE, CONTIUOUS BEDS WITH BLOWOUTS; RESTORATION
	SPA	LARGELY MACROALGAL COVER WITH SCATTERED SEAGRASS PATCHES
	SPAb	LARGELY MACROALGAL COVER WITH SCATTERED SEAGRASS PATCHES; BANKS
	SPH	DENSE PATCHES OF SEAGRASS (>50%) IN A MATRIX OF HARDBOTTOM
	SPHb	DENSE PATCHES OF SEAGRASS (>50%) IN A MATRIX OF HARDBOTTOM; BANKS
	SPHd	DENSE PATCHES OF SEAGRASS (>50%) IN A MATRIX OF HARDBOTTOM; DREDGED/EXCAVATED
	SPP	DOMINANTLY SAND OR MUD WITH SMALL SCATTERED SEAGRASS PATCHES (<50%)
	SPPb	DOMINANTLY SAND OR MUD WITH SMALL SCATTERED SEAGRASS PATCHES (<50%); BANKS
	SPPd	DOMINANTLY SAND OR MUD WITH SMALL SCATTERED SEAGRASS PATCHES (<50%); DREDGED/EXCAVATED
	SPS	DENSE PATCHES OF SEAGRASS IN A MATRIX OF SPARSE SEAGRASS
	SPSb	DENSE PATCHES OF SEAGRASS IN A MATRIX OF SPARSE SEAGRASS; BANKS
	SS	SPARSE, CONTINUOUS BEDS
	SSb	SPARSE, CONTINUOUS BEDS; BANKS
	U	UNMAPPABLE/UNKNOWN BOTTOM

02. Item: AREA_METER	AREA OF BENTHIC HABITAT IN SQUARE METERS
	Type: Integer
	Length: 16
	Decimals: 0
	Format: N/A
	Mandatory: N
	Default Values: 0
	Item Values: N/A

ADDITIONAL METADATA - 1
Benthic Habitats of the Florida Keys Classification System (Data Dictionary)
Cross Reference Table of ARCINFO benthic_g geography and the ArcView Project files.
The benthic habitat types found in the ArcView project files are provided below. Listed in parentheses with each benthic habitat type is the equivalent a_code(s) found in the ARCINFO benthic habitat geography.
Within the ArcView project, benthic habitat modifiers (b - banks; d - dredged/excavated; r - restoration) are provided as a separate thematic layer. As a result, they are not included in this list.
Also within the ArcView project, land (LAND) is provided as a separate thematic layer. As a result, it is not included in this list.
ArcView Shape File Polygon Type	A_CODE in the BENTHIC_G ARCINFO geography
Bare Substrate - Carbonate Mud	BM
Bare Substrate - Carbonate Sand	BS
Bare Substrate - Organic Mud	BO
Continuous Seagrass - Dense Patches in a Matrix of Sparse Seagrass (<50%)	SPS
Continuous Seagrass - Moderate to Dense	SD
Continuous Seagrass - Sparse	SS
Hardbottom - Perceptible Seagrass (<50%)	HS
Hardbottom - Soft Corals, Sponges, Algae	HC
Inland Water	InW
Patch Reefs - Aggregated	CPA
Patch Reefs - Aggregated with Halo	CPIH
Patch Reefs - Coral or Rock Patches with Bare Sand	CPB
Patch Reefs - Halo	CPH
Patch Reefs - Individual	CPI
Patchy Seagrass - Dense Patches in a Matrix of Hardbottom	SPH
Patchy Seagrass - Moderate to Dense with Blowouts	SDB
Patchy Seagrass - Predominantly Microalgae Cover with Scattered Seagrass Patches	SPA
Patchy Seagrass - Predominantly Sand and-or Mud with Small, Scattered Seagrass Patches (<50%)	SPP
Platform Margin Reefs - Back Reef	CB
Platform Margin Reefs - Drowned Spur and Groove	CPSD
Platform Margin Reefs - Reef Rubble	CR
Platform Margin Reefs - Remnant - Low Profile	CPR
Platform Margin Reefs - Shallow Spur and Groove	CPSS
Unknown Bottom	BU; U

More Metadata - 2
Descriptions of Benthic Habitats found in both the benthic_g ARCINFO geography and the ArcView project files.
I. Coral Reefs
	A. Patch Reefs
		Discrete coral communities, typically dome-shaped, usually outside of Hawk Channel, with a few inshore. Can be linear features where several or a series occurs. Mostly off Key Largo and Elliot Key (5,000) with a few off Big Pine, near Key West, and at the Dry Tortugas. Usually composed of hard corals Montastraea sp., Siderastrea sp., Diploria sp., and Colpophyllia sp.. Often surrounded by a whitish appearing halo.
		1. Individual Patch (CPI)
			Isolated, barely visible on aerial photography, with or without a halo.
		2. Aggregated patch reefs (CPA)
			More than one, usually too close together to map individually or where halos coalesce.
		3. Halo (CPH)
			Barren, essentially unvegetated, variable, whitish zone around patch reef resulting from grazing activity of urchins and fishes. Rubble from weathering of patch reef may allow attachment sites for corals to expand the colony. Not always present or large enough to be mapped.
		4. Individual Patch Reef and Halo (CPIH)
			Patch reef and halo combination too small to delineate directly on aerial photography. Delineations of reef and halo performed during compilation.
	B. Platform Margin Reef
		Generally, the "reef tract" or "barrier reef." Extends from northern boundary of the Florida Keys National Marine Sanctuary to west of the Marquesas Keys and also found at the Dry Tortugas. Diverse communities variable in morphology and species composition. Both high and low relief. Includes all coral/hardbottom features distinguishable from "patch reefs."
		1. Spur and Groove
			a. Shallow (e.g., Looe Key) (CPSS)
				Well developed systems on "fore-reef" at major bank reefs on reef tract, with vertical relief to about 4m. Actively growing upward and outward. Distinctive signature on aerial photography due to shallow water (0 - 10m) and high vertical relief. Linear length to approximately 1000m or more.
			b. Drowned (Transitional = older, drowned) (CPSD)
				Older, not actively growing (probably eroding) features often being buried by sand migration from shallower zone of reef tract. Nearly typical spur and groove signature in aerial photographs, but sometimes with less resolution or definition. Usually low profile, about 0.5 - 1.5m. Visible to interpretable depth of photography (10m). Often greater linear length than shallow spur and groove.
		2. Remnant - Low profile (CPR)
			Coral/hardbottom features not exhibiting distinctive signature of spur and groove reefs. Usually parallel to line of reef tract, but may form transverse features perpendicular to the reef tract. Relief from less than 0.5m - 1 or 2m.
	C. Coral Patches in Bare Sand (CPB)
		Very sparse features that are similar in nature to patch reefs, but are on the outer reef tract. These areas are dominantly sand or a veneer of sand over low relief rock. Scattered throughout are small patches ranging from a single gorgonian, sponge, or small coral head up to a low assemblage that may be a few meters to 10m across. These patches make up a low percentage of the total cover, yet are distinctive. This class is found mainly in the area from Big Pine Shoal to Sombrero Light, and may be associated with the lack of a developed forereef structure in this area.
	D. Back Reef (CB)
		Shallow (<2m) platform landward of spur and groove features on bank reefs, typically rubble zone colonized with numerous soft corals and pioneering staghorn, fire and other hard corals. Corals here are widely spaced individuals on a rubble platform.
	E. Reef Rubble (CR)
		Zone landward of bank reefs and other high energy reef tract areas where unstable rubble exists with little or no visible colonization. In relatively shallow water (1 - 6m) often in association with Thallassia or Syringodium. Signature on the aerial photographs is distinctive from other coral/hardbottom communities. May form transverse features perpendicular to line of reef tract.
II. Hardbottom (Inshore only, stops at Hawk Channel for the Florida Keys National Marine Sanctuary)
	Solid, flat, low-relief substrate composed of Key Largo limestone (from west end of the Newfound Harbor Keys off Big Pine to the north edge of the Florida Keys National Marine Sanctuary) or Miami oolite (Big Pine Key and west). Depth ranges from intertidal to approximately 7m in deep tidal channels and the inside edge of Hawk Channel. May include a thin veneer of carbonate sand or mud, too thin and unstable to support seagrass.
	A. Soft Coral, Hard Coral, Sponge, Algae (HC)
		Benthic community (no perceptible seagrass) is variable and typically a function of sediment, water, depth, and exposure to wind and current. May also include solitary hard corals, Porites sp., Sideratrea sp., and Manicina sp.. Shallowest zones (<1m) may include only attached or drift algae; soft corals are usually more common in deeper zones.
	B. Hardbottom with perceptible seagrass (<50%) (HS)
		Usually in patches, seagrasses occur in depressions and basins where adequate sediment has accumulated, but constitute <50% bottom coverage. Hard bottom may include solitary hard corals and soft corals, but most often sponges and benthic algae (attached or in draft).
III. Bare Substrate
	Open and essentially unvegetated, with no benthic community visible on photographs, due to unstable nature of substrate. Can be large seagrass blowouts or active erosional features. Largest areas are on reef tract, in the bottom of Hawk Channel and west of the Marquesas Keys. May have sparse, ephemeral benthic algae or diatom films that are not detectable on photography. Diatom films may develop in a few days.
	A. Carbonate Sand (usually exposed locations) (BS)
		Sand-size carbonate sediments, usually in areas exposed to current and wind energy that continually sort out and remove finer sediment fractions.
	B. Carbonate Mud (usually protected location) (BM)
		Fine carbonate sediments in deep water (Hawk Channel) or locations protected from wind and wave energy. More depositional than erosional.
	C. Organic Mud (BO)
		On windward shorelines where drift seagrass and algae builds up in intertidal and shallow water. Continual deposition and resuspension of organic matter limits development of benthic community on natural as well as disturbed shorelines. Especially common feature on windward shorelines of Big Pine, No Name, and Little Pine Keys.
IV. Seagrass
	A. Moderate to Dense, continuous beds (SD)
		Solid, continuous Thalassia, Syringodium, and Halodule, individually or in mixed beds. Widespread in occurrence with range in depth from intertidal (bank) to approximately 10m.
	B. Moderate to Dense, nearly continuous beds (seagrass>50%), with blowouts and/or sand or mud patches. (SDB)
		Solid, continuous Thalassia or Syringodium, rarely Halodule, individually or in mixed beds. Widespread in occurrence with range in depth from intertidal (bank) to approximately 10m. Moderate to high energy regimes. Here, blowouts or patches are dispersed as holes in otherwise continuous seagrass beds. Usually found on reef tract and near entrances to tidal channels and passes. A common habitat in back country of middle keys with large water movements between the Gulf of Mexico and Atlantic Ocean.
	C. Sparse, continuous beds (SS)
		Areas where seagrasses occur in low density (<50 shoots/m sq.). Typically in shallow protected bays where physical conditions or substrate limits development. May be hard to distinguish signature on aerial photographs from barren bottom, requiring ground truthing.
	D. Patchy
		Typically the result of depressional basins or creek-like features in seabed that accumulate sediment or contain organic peat deposits from mangrove community occurring during lower sea level. This greater depth of sediment allows seagrass development in an area, or allows denser seagrasses compared to surrounding areas. Widespread feature in inshore areas throughout the Florida Keys National Marine Sanctuary and Biscayne Bay.
		1. Dense patches of seagrass (>50%) in a matrix of Hardbottom. (SPH)
			One of the most common habitat types; patches occur in areas where a thin sediment layer over flat natural rock precludes development of seagrasses. Often numerous in number, highly visible on aerial photographs.
		2. Dense patches of seagrass in a matrix of sparse seagrass. (SPS)
			Depressional features with deep sediment allow denser development of seagrasses than on surrounding bottoms where only a thin layer may be present. May be difficult to discern on aerial photographs from seagrass patches in hardbottom. May occur more in deeper water or protected bays.
		3. Dominantly sand or mud with small scattered seagrass patches (<50%). (SPP)
			Large sand features with recognizable seagrass patches. Similar location to seagrass with blow-outs. Substrate may vary from sand to mud, and algae, either fixed or drift, may be a significant component. Offshore features tend to be more sandy, and inshore protected areas tend to be muddier in composition.
		4. Largely MacroAlgal cover with scattered seagrass patches. (SPA)
			Scattered seagrass patches are a significant habitat component, but dominant is background of macroalgae. Algal cover is banks of Halimeda sp. or Pencillus sp. May be difficult to delineate on aerial photographs without ground truthing.
V. Special Modifiers
	Special Modifiers are attached to a specific community type when applicable. Ex. SDb; BSDBr
	A. Banks (Xb)
		Intertidal seagrass and some hardbottom communities, even if only intertidal at spring low tides, often open water features or extending out from a shoreline. Distinctive signature on aerial photographs compared to surrounding bottom. Sometimes burned off patches are present on bank top. If these patches become large enough, they are mapped as separate bare areas.
	B. Dredged/Excavation (Xd)
		Those locations where dredging or excavation has occurred for channels, rock mines, or anchorages.
	C. Restoration (Xr)
		Site of fill placement or backfilling of dredged area to restore original elevations and intertidal or benthic community. Modifier applied to resulting benthic community. Local knowledge of restoration sites necessary.
VI. Bottom Unknown, Unmappable, or Uninterpretable (BU; U)
	This refers to those areas that are beyond the depth threshold of the aerial photography (approximately 9m), and/or uninterpretable due to glare, or turbid waters. Most narrow or deep access channels such as Key West Harbor, Hawk Channel, or the deeper sides of the reef tract.

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