Identification_Information:
  Native_Data_Set_Environment: Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcCatalog 9.1.0.780
  Description:
    Abstract: This data set contains the major biological cover type derived from benthic habitat data for the island of Guam, which was developed between June 2004 and September 2005. This benthic habitat data set was developed as part of the Guam Coastal Atlas (www.uog.edu/marinelab/coastal.atlas/), which provides updated coastal information for the island of Guam. The benthic habitat data set developed by the NOAA Biogeography Team between 2003 and 2004 served as the starting point for the development of this data set. An enhanced level of detail was achieved with this data set by using pan-sharpened IKONOS imagery as a base layer for feature digitization and by using a smaller minimum map unit than that used for the development of the NOAA Biogeography Team benthic habitat data set. A significant number of additional ground-truthing points were also collected throughout the development of the data set. As of the publication time of this data set, a final accuracy assessment had not been performed and thus the accuracy of any changes made to the original NOAA Biogeography Team data set have not been verified.
    Purpose: This data set was developed for the Guam Coastal Atlas Project and is intended to serve as the primary source of benthic habitat information for the island of Guam.
  Citation:
    Citation_Information:
      Originator: David R. Burdick, 2004-2007 NOAA Pacific Islands Assistant for Guam
      Publication_Date: February, 2006
      Title: Benthic habitat (biological cover)
      Geospatial_Data_Presentation_Form: vector digital data
      Edition: First
      Online_Linkage: www.uog.edu/marinelab/coastal.atlas/
      Originator: University of Guam Marine Laboratory
  Time_Period_of_Content:
    Currentness_Reference: ground condition
    Time_Period_Information:
      Range_of_Dates/Times:
        Beginning_Date: 2001
        Beginning_Time: unknown
        Ending_Date: 2004
        Ending_Time: unknown
  Status:
    Progress: Complete
    Maintenance_and_Update_Frequency: Unknown
  Spatial_Domain:
    Bounding_Coordinates:
      West_Bounding_Coordinate: 144.599648
      East_Bounding_Coordinate: 144.972700
      North_Bounding_Coordinate: 13.669406
      South_Bounding_Coordinate: 13.222290
  Access_Constraints: None
  Use_Constraints: This data is not to be used for navigational purposes.
  Point_of_Contact:
    Contact_Information:
      Contact_Organization_Primary:
        Contact_Organization: University of Guam Marine Laboratory
        Contact_Person: Barry Smith
      Contact_Position: Director
      Contact_Voice_Telephone: (671) 735-2175
      Contact_Facsimile_Telephone: (671) 734-6767
      Contact_Electronic_Mail_Address: bdsmith@uog9.uog.edu
      Contact_Address:
        Address_Type: mailing and physical address
        City: Mangilao
        State_or_Province: GU
        Postal_Code: 96923
        Country: Guam/USA
        Address: Marine Laboratory
        Address: University of Guam
  Data_Set_Credit: David R. Burdick, 2004-2007 NOAA Pacific Islands Assistant for Guam
  Keywords:
    Theme:
      Theme_Keyword: major structure
      Theme_Keyword: benthic habitat
      Theme_Keyword: reef
      Theme_Keyword: coastal atlas
    Place:
      Place_Keyword: Guam
      Place_Keyword: U.S. Territory
      Place_Keyword: Mariana Islands
      Place_Keyword: Micronesia
      Place_Keyword: Northwest Pacific
      Place_Keyword: Western Pacific
      Place_Keyword: Pacific Islands
Metadata_Reference_Information:
  Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
  Metadata_Standard_Version: FGDC-STD-001-1998
  Metadata_Time_Convention: local time
  Metadata_Contact:
    Contact_Information:
      Contact_Organization_Primary:
        Contact_Person: Barry Smith
        Contact_Organization: University of Guam Marine Laboratory
      Contact_Voice_Telephone: (671) 735-2175
      Contact_Position: Director
      Contact_Facsimile_Telephone: (671) 734-6767
      Contact_Electronic_Mail_Address: bdsmith@uog9.uog.edu
      Contact_Address:
        Address: Marine Laboratory
        Address_Type: mailing and physical address
        Address: University of Guam
        City: Mangilao
        State_or_Province: GU
        Postal_Code: 96923
        Country: Guam/USA
  Metadata_Date: 20070809
  Metadata_Access_Constraints: None
  Metadata_Use_Constraints: None
  Metadata_Review_Date: 20101012
Distribution_Information:
  Resource_Description: Downloadable Data
  Standard_Order_Process:
    Digital_Form:
      Digital_Transfer_Information:
        Transfer_Size: 5.505
Spatial_Data_Organization_Information:
  Direct_Spatial_Reference_Method: Vector
  Point_and_Vector_Object_Information:
Spatial_Reference_Information:
  Horizontal_Coordinate_System_Definition:
    Planar:
      Planar_Coordinate_Information:
        Planar_Coordinate_Encoding_Method: coordinate pair
        Planar_Distance_Units: meters
        Coordinate_Representation:
          Abscissa_Resolution: 0.000128
          Ordinate_Resolution: 0.000128
    Geodetic_Model:
      Horizontal_Datum_Name: D_WGS_1984
      Ellipsoid_Name: WGS_1984
      Semi-major_Axis: 6378137.000000
      Denominator_of_Flattening_Ratio: 298.257224
  Vertical_Coordinate_System_Definition:
    Altitude_System_Definition:
      Altitude_Encoding_Method: Explicit elevation coordinate included with horizontal coordinates
      Altitude_Resolution: 0.000010
Entity_and_Attribute_Information:
  Detailed_Description:
    Entity_Type:
      Entity_Type_Label: benthic_habitat_general_cover
    Attribute:
      Attribute_Label: OBJECTID
      Attribute_Definition: Internal feature number.
      Attribute_Definition_Source: Esri
      Attribute_Domain_Values:
        Unrepresentable_Domain: Sequential unique whole numbers that are automatically generated.
    Attribute:
      Attribute_Label: Shape
      Attribute_Definition: Feature geometry.
      Attribute_Definition_Source: ESRI
      Attribute_Domain_Values:
        Unrepresentable_Domain: Coordinates defining the features.
    Attribute:
      Attribute_Label: M_COVER
    Attribute:
      Attribute_Label: Area_ha
    Attribute:
      Attribute_Label: Area_ac
    Attribute:
      Attribute_Label: Shape_Length
      Attribute_Definition: Length of feature in internal units.
      Attribute_Definition_Source: Esri
      Attribute_Domain_Values:
        Unrepresentable_Domain: Positive real numbers that are automatically generated.
    Attribute:
      Attribute_Label: Shape_Area
      Attribute_Definition: Area of feature in internal units squared.
      Attribute_Definition_Source: Esri
      Attribute_Domain_Values:
        Unrepresentable_Domain: Positive real numbers that are automatically generated.
Data_Quality_Information:
  Logical_Consistency_Report: The logical consistency of the geometry of this data set was checked using the topology functions of ArcGIS 9.0.  Once all of the features were digitized, the shapefile was converted to a geodatabase feature class and a topology layer was created within ArcCatalog.  The topology rules used to create the layer include "features must not overlap" and "features must not have gaps."  All errors detected upon validation of the layer topology were corrected manually within ArcMap.  The topologically-clean feature class was converted to a shapefile for publication.  The logical consistency of the attributes of this layer was checked manually.
  Attribute_Accuracy:
    Attribute_Accuracy_Report: An attribute accuracy assessment had not been conducted prior to the release of this data set.  At the time of publication, there are no plans to conduct an accuracy assessment.
  Completeness_Report: This data set is considered complete.  Presently, there are no plans to conduct an accuracy assessment.  Updates may be provided at a later date as more ground-truthing information becomes available.
  Lineage:
    Process_Step:
      Process_Contact:
        Contact_Information:
          Contact_Address:
            Address_Type: mailing and physical address
            City: Mangilao
            State_or_Province: GU
            Postal_Code: 96923
            Country: Guam/USA
            Address: Marine Laboratory
            Address: University of Guam
          Contact_Organization_Primary:
            Contact_Organization: University of Guam Marine Laboratory
            Contact_Person: David Burdick
          Contact_Position: NOAA Pacific Islands Assistant for Guam
          Contact_Voice_Telephone: (671) 735-2175
          Contact_Facsimile_Telephone: (671) 743-6767
          Contact_Electronic_Mail_Address: bdsmith@uog9.uog.edu
      Process_Description:
        Methods Overview:
        Benthic habitat data for Guam developed by the National Oceanic and Atmospheric Administration (NOAA) National Centers for Coastal Ocean Science (NCCOS) Biogeography Team served as the starting point for the benthic habitat maps used in the Guam Coastal Atlas. The NOAA Biogeography Team's benthic habitat data were created by visual interpretation of IKONOS satellite imagery captured between 2001 and 2003 and validated by in situ surveys (for more information regarding the methods used by the NOAA Biogeography Team to develop their benthic habitat data for Guam, please visit their website at http://biogeo.nos.noaa.gov. The NOAA Biogeography Team's benthic habitat data utilized an average minimum mapping unit of approximately 1 acre (4,046.86 sq. meters), however, and did not fully take advantage of the high level of detail that the IKONOS imagery allowed. 

             In order to update the NOAA Biogeography Team's benthic habitat data and enhance the level of detail for select portions of the data set, the most recently (2001 - 2004) available multispectral IKONOS image mosaic and a significantly smaller minimum map unit was used. An average minimum map unit of approximately 1/8 acre was used for the mapping of benthic habitats in four of Guam's marine preserves and other "focus areas"; some polygons with an area less than the minimum mapping unit occur in the data, however. The IKONOS imagery was pan-sharpened using ERDAS Imagine image processing software. The heads-up digitizing functions of ArcGIS were then used to adjust the boundaries of the existing benthic habitat data, create new features, and update feature attribute information. A hierarchical classification scheme similar to that used by the NOAA Biogeography Team was adopted for the data used in the Guam Coastal Atlas.

               Four of Guam's marine preserves (Tumon Bay, Piti Bomb Holes, Achang Reef Flat, and Sasa Bay Preserves), as well as Cocos Lagoon, Pago Bay, and East Agana Bay, were targeted for highly detailed benthic habitat interpretation using the smaller minimum map unit; more detailed benthic habitat maps for other coastal areas may become available at a later date. Benthic habitat maps for much of the area beyond the marine preserve boundaries and the focus areas utilized the original NOAA Biogeography Team benthic habitat data, although some alterations (e.g. polygon boundary adjustments, classification corrections/updates) were performed. Ground validation surveys were also performed during the development of the Guam Coastal Atlas with a Trimble GeoXT hand-held GPS receiver that collected GPS-referenced benthic habitat information in situ. Accuracy assessment surveys were not conducted upon completion of the benthic habitat data set, thus the percent accuracy for the data is unknown. An accuracy assessment was performed for data developed by the NOAA Biogeography Team. Because of changes made to the NOAA Biogeography Team's benthic habitat data set for use in the Guam Coastal Atlas, the level of accuracy achieved with the NOAA data does not apply to the data used in the Guam Coastal Atlas. Please refer to the NOAA Biogeography Project Web site (http://biogeo.nos.noaa.gov) for more information about their accuracy verification surveys. 

        Classification Scheme:
        A hierarchical classification scheme similar to that used by the NOAA team was adopted for the benthic habitat data used in the Guam Coastal Atlas. Using this classification scheme, benthic habitats were described from the broadest level of classification (unconsolidated sediment or coral reef/hard bottom) to a very detailed level of classification (e.g. 50%-<90% macroalgae). The major structure (unconsolidated sediment or coral reef/hard bottom), the detailed structure (e.g. aggregated reef, pavement, patch reef, etc.), the major cover type (e.g. coral, macroalgae, turf algae, uncolonized, etc.), and the percent cover of the major cover type (e.g. 0%, 1%-<10%, 10%<50%, etc.) were also recorded for each habitat delineation.

               Although the benthic habitat data developed for the Guam Coastal Atlas used the same classification scheme as that used by the NOAA Biogeography Team, slightly different rules were used to determine the classification an area was to receive. These changes include:

                  - Defining coral as the majority cover type if the coral percent cover was 10% or greater

                  - Defining macroalgae as the major cover type if the macroalgae percent cover was 10% or greater and if coral cover was less than 10%. 

               Additionally, reef zone attribute information provided with the NOAA Biogeography Team benthic habitat data was not preserved during the development of the data for the Guam Coastal Atlas. Instead, adjacent polygons occurring in different reef zones (e.g. reef crest, reef flat, etc.) that otherwise possessed identical habitat classifications were merged in order to simplify the data set and reduce "clutter" on the benthic habitat maps. For more information about the classification scheme produced by the NOAA Biogeography Team and adopted for the Guam Coastal Atlas, including photos of various benthic habitat types, please visit their website at http://biogeo.nos.noaa.gov/products/us_pac_terr.

        Ground Validation Surveys:
        A series of ground validation surveys were performed during the development of the benthic habitat data set. A Trimble GeoXT handheld GPS receiver was used to collect benthic habitat information. During these surveys, benthic habitat was described at each of the numerous data points collected throughout the study area. Using the hierarchical classification scheme, the benthic habitat at each point was described from the most basic level of detail (unconsolidated sediment or coral reef/hard bottom) to a high level of detail (e.g. 50% to < 90% macroalgae). The major structure (unconsolidated sediment or coral reef/hard bottom), the detailed structure (e.g. aggregated reef, pavement, patch reef, etc.), the major cover type (e.g. coral, macroalgae, turf algae, uncolonized, etc.), the percent cover of the dominant cover type (e.g. 0%, 1% to < 10%, 10% to < 50%, etc.), as well as the percent cover of coral were recorded for a 1 meter x 1 meter area beneath each point. A large portion of the data points collected at Gab Gab Beach, Dadi Beach, and Tumon Bay also included a digital photograph of a 0.25 sq. meter quadrat in order to assist in the interpretation of benthic habitats using the IKONOS imagery and to compare to future surveys. 

                 A total of 846 ground validation points were collected at various sites around the island (see figures at lower left and lower right). The 203 ground validation points and the 241 accuracy assessment points collected by the NOAA Biogeography team were also used to help interpret the satellite imagery.

                 Because of environmental conditions, field surveys were limited mostly to the shallow reef flat areas around Guam. Ground validation data was collected with the GPS receiver within the Tumon Bay, Pati Point, and Achang Reef Flat Preserves, as well as at East Agana Bay, Cocos Lagoon, Pago Bay, Ritidian Point, and Gab Gab and Dadi Beaches on U.S. Navy Base property. A much wider cross-section of coastal area, including many fore reef areas, was observed and documented using a digital still camera during snorkeling and scuba diving excursions. These in situ observations allowed for a general assessment of an area's benthic habitat composition and assisted with the interpretation of the satellite imagery, and improved the accuracy of the benthic habitat classification in areas not surveyed using the GPS receiver.

        Accuracy Assessment:
        An accuracy assessment had not been performed prior to the production of the printed and CD-ROM versions of the Guam Coastal Atlas, so the accuracy of any changes made to the original NOAA Biogeography Team's benthic habitat data during the development of the Guam Coastal Atlas have not been assessed. An accuracy assessment will likely be performed at a later date. This information will be available on the Guam Coastal Atlas web site at http://www.uog.edu/marinelab/coastal.atlas/.
      Process_Date: June 2004 - September 2005
    Process_Step:
      Process_Description: The original data set was dissolved based on the major biological cover type (M_COVER). Two new fields (Area in hectare and acres) were added and populated.
      Time_of_Day: 12292100
      Process_Contact:
        Contact_Information:
          Contact_Organization_Primary:
            Contact_Organization: Island Research & Education Initiative
          Contact_Electronic_Mail_Address: irei@islandresearch.org
      Process_Date: August 2013
Lineage:
