Identification_Information: Citation: Citation_Information: Originator: Seth Barker, Independent Contractor Publication_Date: 20180228 Title: Great Bay Estuary Eelgrass, 2017 Geospatial_Data_Presentation_Form: vector digital data Online_Linkage: Description: Abstract: The dataset shows the locations where eelgrass was observed in the Great Bay Estuary based on photointerpretation of orthophotography collected on August 24, 2017. The study area includes the following waterbodies: Great Bay, the mouth of the Squamscott River, the tidal portion of the Lamprey River, the tidal portion of the Oyster River, the tidal portion of the Bellamy River, the Piscataqua River and Portsmouth Harbor and its associated creeks. Vertical aerial photography was collected as digital 4-band imagery with a nominal 1 foot resolution using an Intergraph Digital Mapping Camera. Environmental conditions included a low-sun angle, low spring tide, low cloud cover, calm winds, no preceding rain events, and low turbidity in the water column. The eelgrass habitat mapped from the aerial imagery was verified using the ground truthing data from preselected locations and ad hoc locations chosen during the course of the field work. Ground truthing was done from a small boat during the same season as the photographs were taken. Ground truth observations were made on all tides using a drop camera with video recording capabilities and at low tide when visual observations were recorded. Positions were determined using high accuracy Trimble GeoXH and GeoXT GPS units and a Garmin Colorado 400c as a backup. Purpose: The dataset was developed to monitor the distribution of eelgrass within the Great Bay Estuary over time. The surveys have been completed yearly since 1986 to track trends over time. A final report on this project is available at: https://scholars.unh.edu/prep/407/ Time_Period_of_Content: Time_Period_Information: Single_Date/Time: Calendar_Date: 20170824 Currentness_Reference: Ground Date Status: Progress: Complete Maintenance_and_Update_Frequency: Annually Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -70.911297 East_Bounding_Coordinate: -70.677157 North_Bounding_Coordinate: 43.153869 South_Bounding_Coordinate: 43.049923 Keywords: Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: biota Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: Eelgrass Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: Estuary Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: Estuarine Place: Place_Keyword_Thesaurus: ISO 19115 Topic Category Place_Keyword: oceans Place_Keyword: Northeast Place_Keyword: New England Place_Keyword: New Hampshire Place_Keyword: Great Bay Place_Keyword: Little Harbor Place_Keyword: Piscataqua River Place_Keyword: Lamprey River Place_Keyword: Oyster River Place_Keyword: Bellamy River Place_Keyword: Portsmouth Harbor Place_Keyword: Squamscott River Place_Keyword: New Castle Place_Keyword: Rye Place_Keyword: Portsmouth Place_Keyword: Newington Place_Keyword: Greenland Place_Keyword: Stratham Place_Keyword: Newfields Place_Keyword: Newmarket Place_Keyword: Durham Place_Keyword: Dover Place_Keyword: Madbury Place_Keyword: Eliot Place_Keyword: Kittery Place_Keyword: Maine Access_Constraints: None Use_Constraints: User is required to read metadata completely before using the data. The information provided in this coverage was developed by an independent contractor and used by the NH Department of Environmental Services (NHDES). Development of these databases is an ongoing project; they may not contain all existing and potential sites, stations, or threats. The NHDES is not responsible for the use or interpretation of this information, or for any inaccuracies in the site names or locations. All information is subject to verification. These data are to be used for planning purposes only; distribution is discouraged. Point_of_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Kalle Matso Contact_Organization: Piscataqua Region Estuaries Partnership, University of New Hampshire Contact_Position: Science Program Manager Contact_Address: Address_Type: Mailing and Physical Address Address: Nesmith Hall, 131 Main St. City: Durham State_or_Province: New Hampshire Postal_Code: 03824 Contact_Voice_Telephone: 603-781-6591 Native_Data_Set_Environment: Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 2; ESRI ArcGIS 10.0.4.4000 Data_Quality_Information: Logical_Consistency_Report: Note that yearly variations in collection methods exist. Following is a summary of methods that have been used. The eelgrass habitat mapped from the aerial imagery is verified using the ground truthing data by placing the ground-truthing locations onto the digital image using GIS software. Ground-truthing is done from a small boat during the same season as the photographs are taken. Ground-truth observations are made at low tide or at other tide stages using a drop camera. Positions are determined using GPS. Gaps, overlapping polygon areas and duplicate polygons are identified and removed. Completeness_Report: The dataset is complete. There are no known omissions. Lineage: Process_Step: Process_Description: The final photomosaics were received in December, 2017, from Kappa Mapping. These were added to a GIS along with field information and other data layers to aid in photointerpretation. Eelgrass beds were first outlined and screen digitized using the GIS software packages, QGIS, and saved to an ESRI shape file. Digitizing was generally done at a screen scale of 1:1000 or greater. The minimum mapping unit for the delineation of eelgrass features was generally 100 square meters. However, smaller features were included in the dataset if they could be clearly discerned as pure eelgrass beds.The projection used was New Hampshire State Plane, NAD83, and the units were feet. Process_Date: 20180228 Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Kalle Matso Contact_Organization: Piscataqua Region Estuaries Partnership, University of New Hampshire Contact_Position: Science Program Manager Contact_Address: Address_Type: Mailing and Physical Address Address: Nesmith Hall, 131 Main St. City: Durham State_or_Province: New Hampshire Postal_Code: 03824 Contact_Voice_Telephone: 603-781-6591 Spatial_Data_Organization_Information: Direct_Spatial_Reference_Method: Vector Point_and_Vector_Object_Information: SDTS_Terms_Description: SDTS_Point_and_Vector_Object_Type: G-polygon Point_and_Vector_Object_Count: 124 Spatial_Reference_Information: Horizontal_Coordinate_System_Definition: Planar: Grid_Coordinate_System: Grid_Coordinate_System_Name: State Plane Coordinate System 1983 State_Plane_Coordinate_System: SPCS_Zone_Identifier: 2800 Transverse_Mercator: Scale_Factor_at_Central_Meridian: 0.999967 Longitude_of_Central_Meridian: -71.666667 Latitude_of_Projection_Origin: 42.500000 False_Easting: 984250.000000 False_Northing: 0.000000 Planar_Coordinate_Information: Planar_Coordinate_Encoding_Method: coordinate pair Coordinate_Representation: Abscissa_Resolution: 0.002048 Ordinate_Resolution: 0.002048 Planar_Distance_Units: survey feet Geodetic_Model: Horizontal_Datum_Name: North American Datum of 1983 Ellipsoid_Name: Geodetic Reference System 80 Semi-major_Axis: 6378137.000000 Denominator_of_Flattening_Ratio: 298.257222 Entity_and_Attribute_Information: Detailed_Description: Entity_Type: Entity_Type_Label: eelgrass2017 Entity_Type_Definition: Each polygon of eelgrass habitat is assigned an id. Entity_Type_Definition_Source: Seth Barker, Consultant Attribute: Attribute_Label: FID 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: HECTARES Attribute_Definition: Eelgrass area in hectares. Attribute_Definition_Source: Seth Barker, Consultant Attribute_Domain_Values: Unrepresentable_Domain: Calculated value. Attribute: Attribute_Label: ACRES Attribute_Definition: Acreage of the eelgrass area. Attribute_Definition_Source: Seth Barker, Consultant Attribute_Domain_Values: Unrepresentable_Domain: Calculated value. Attribute: Attribute_Label: YEAR Attribute_Definition: The year that the data was collected. Attribute_Definition_Source: Seth Barker, Consultant Attribute_Domain_Values: Unrepresentable_Domain: Calculated value. Attribute: Attribute_Label: 100 M2? Attribute_Definition: Polygon is equal to or larger than minimum mapping unit (MMU) of 100 M2. Attribute_Definition_Source: Seth Barker, Consultant Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: y Enumerated_Domain_Value_Definition: Yes Enumerated_Domain_Value_Definition_Source: None Enumerated_Domain: Enumerated_Domain_Value: n Enumerated_Domain_Value_Definition: No Enumerated_Domain_Value_Definition_Source: None Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: Earth Systems Research Center, University of New Hampshire Contact_Person: GRANIT Database Manager Contact_Position: GRANIT Database Manager Contact_Address: Address_Type: mailing and physical address Address: Morse Hall, University of New Hampshire City: Durham State_or_Province: NH Postal_Code: 03824 Contact_Voice_Telephone: 603-862-1792 Contact_Facsimile_Telephone: 603-862-0188 Contact_Electronic_Mail_Address: granit@unh.edu Hours_of_Service: 8:30AM-5PM. EST Resource_Description: Downloadable Data Distribution_Liability: Digital data in NH GRANIT represent the efforts of the contributing agencies to record information from the cited source materials. Earth Systems Research Center, under contract to the NH Office of Strategic initiatives, and in consultation with cooperating agencies, maintains a continuing program to identify and correct errors in these data. OSI, ESRC, and the cooperating agencies make no claim as to the validity or reliability or to any implied uses of these data. Standard_Order_Process: Digital_Form: Digital_Transfer_Information: Format_Name: ESRI shapefile Transfer_Size: <1 MB Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: URL:http://www.granit.sr.unh.edu Fees: No charge when downloaded from the Internet. Cost of reproduction for provision on CD/ROM of other media. Ordering_Instructions: Email GRANIT (granit@unh.edu) or order from web site (www.granit.unh.edu). Turnaround: Two weeks Technical_Prerequisites: None Metadata_Reference_Information: Metadata_Date: 20170305 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Person: Kalle Matso Contact_Organization: Piscataqua Region Estuaries Partnership, University of New Hamps..hire Contact_Position: Science Program Manager Contact_Address: Address_Type: mailing and physical address Address: Newmith Hall, 131 Main St. City: Durham State_or_Province: New Hampshire Postal_Code: 03824 Contact_Voice_Telephone: 603-891-6591 Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-2001 Metadata_Time_Convention: local time Metadata_Extensions: Online_Linkage: Profile_Name: ESRI Metadata Profile Metadata_Extensions: Online_Linkage: http://www.esri.com/metadata/esriprof80.html Profile_Name: ESRI Metadata Profile