Metadata: Identification_Information: Citation: Citation_Information: Originator: Michael Routhier, UNH, Geospatial Science Center Publication_Date: 20240415 Title: Great Bay Estuary Eelgrass, 2023 Geospatial_Data_Presentation_Form: vector digital data Online_Linkage: https://nhgeodata.unh.edu/nhgeodata/rest/services/Topical/CV_BiologyAndEcology/MapServer/32 Online_Linkage: https://ftp.granit.sr.unh.edu/GRANIT_Data/Vector_Data/Biology_and_Ecology/eelgrass/2023/ Description: Abstract: The dataset shows the locations where eelgrass was observed within 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, and the coastal shore of Odiorne Point. Photointerpretation was completed on unoccupied aerial vehicle (UAV) collected orthophotography, Sentinel satellite imagery, and non-geo-rectified aerial digital photos taken with a downward pointing GoPro camera mounted to the underside of a light airplane. Vertical 2-6 cm spatial resolution UAV imagery was collected between late May through October 2023 over the study area inclusive of RGB, Red-Edge, and Near Infrared bands. Sentinel satellite imagery was collected for the dates of August 22nd, September 4th, and October 4th, 2023, over the study area at a 10 m spatial resolution. The eelgrass habitat mapped from the above listed 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. Database file attributes for the 2023 survey are as follows: “id,” a unique consecutive number; “Hectares,” the area of the polygon in hectares; “Acres,” the area of the polygon in acres; “Year,” equal to 2023, the year of the imagery used, “Label” for the assessment zone, and “type” to distinguish between polygons mapped as eelgrass, widgeon grass, or both, “Confidence,” a measure of cartographer confidence (H = Higher, M = Medium, L = Lower) of the existence and/or cover type of vegetation per polygon. “Notes,” a text field listing the types of imagery used and/or mapping limitations per polygon as observed by the cartographer. The items “Confidence” and “Notes” were added to help record varying vegetation mapping confidence levels caused by high turbidity and/or depth clarity issues with this year’s imagery. Purpose: The dataset was developed to monitor the distribution of eelgrass within the Great Bay Estuary over time. With the exception of 2018 and 2020, surveys have been completed yearly since 1986 to track trends over time. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 20230601 Ending_Date: 20231001 Currentness_Reference: Ground condition Status: Progress: Complete Maintenance_and_Update_Frequency: Annually Spatial_Domain: Bounding_Coordinates: West_Bounding_Coordinate: -70.904694 East_Bounding_Coordinate: -70.678503 North_Bounding_Coordinate: 43.128019 South_Bounding_Coordinate: 43.040561 Keywords: Theme: Theme_Keyword_Thesaurus: ISO 19115 Topic Category Theme_Keyword: biota Theme: Theme_Keyword_Thesaurus: None Theme_Keyword: Eelgrass Theme_Keyword: Estuary Theme_Keyword: Estuarine Theme_Keyword: Biology Theme_Keyword: Ecology 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 dataset 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_Organization_Primary: Contact_Organization: Piscataqua Region Estuaries Partnership, University of New Hampshire Contact_Person: Kalle Matso Contact_Position: Science Program Manager Contact_Address: Address_Type: mailing and physical Address: Nesmith Hall, 131 Main St. City: Durham State_or_Province: New Hampshire Postal_Code: 03824 Contact_Voice_Telephone: 603-781-6591 Data_Set_Credit: Michael Routhier, UNH, Geospatial Science Center Native_Data_Set_Environment: ArcGIS Pro 2.4.0. 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 dropcamera. Positions are determined using GPS. Completeness_Report: The dataset is complete. There are no known omissions. Lineage: Process_Step: Process_Description: Eelgrass (Zostera marina) distribution in Great Bay, Little Bay, and the Piscataqua River Estuary was mapped using 10m spatial resolution European Space Agency (ESA) Sentinel satellite imagery, 14.5cm spatial resolution digital aerial photography, and 1.7 to 3.4 cm spatial resolution low-altitude drone imagery. Eelgrass beds were first outlined and screen digitized using ArcGIS Pro software and saved to an ESRI shapefile. Digitizing was generally completed 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: 20240415 Process_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Piscataqua Region Estuaries Partnership, University of New Hampshire Contact_Person: Kalle Matso Contact_Position: Science Program Manager Contact_Address: Address_Type: mailing and physical 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: GT-polygon composed of chains Point_and_Vector_Object_Count: 119 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: eelgrass2023 Entity_Type_Definition: Each polygon of eelgrass habitat is assigned an id. Entity_Type_Definition_Source: Michael Routhier, UNH, Geospatial Science Center 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: Geospatial Science Center Attribute_Domain_Values: Unrepresentable_Domain: Calculated value. Attribute: Attribute_Label: ACRES Attribute_Definition: Acreage of the eelgrass area. Attribute_Definition_Source: Geospatial Science Center Attribute_Domain_Values: Unrepresentable_Domain: Calculated value. Attribute: Attribute_Label: YEAR Attribute_Definition: The year that the data was collected. Attribute_Definition_Source: Geospatial Science Center Attribute_Domain_Values: Unrepresentable_Domain: Calculated value. Attribute: Attribute_Label: LABEL Attribute_Definition: Assessment Zone Attribute_Definition_Source: Geospatial Science Center Attribute_Domain_Values: Unrepresentable_Domain: None Attribute: Attribute_Label: Type Attribute_Definition: SAV type Attribute_Definition_Source: Michael Routhier, UNH, Geospatial Science Center Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: 1 Enumerated_Domain_Value_Definition: Eelgrass Enumerated_Domain_Value_Definition_Source: None Enumerated_Domain: Enumerated_Domain_Value: 2 Enumerated_Domain_Value_Definition: Eelgrass and Widgeon grass Enumerated_Domain_Value_Definition_Source: None Enumerated_Domain: Enumerated_Domain_Value: 3 Enumerated_Domain_Value_Definition: Widgeon grass Enumerated_Domain_Value_Definition_Source: None Attribute: Attribute_Label: Name Attribute_Definition: SAV Name Attribute_Definition_Source: Michael Routhier, UNH, Geospatial Science Center Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: Eelgrass Enumerated_Domain_Value_Definition: Eelgrass Enumerated_Domain_Value_Definition_Source: None Enumerated_Domain: Enumerated_Domain_Value: Eelgrass and Widgeon Grass Enumerated_Domain_Value_Definition: Eelgrass and Widgeon Grass Enumerated_Domain_Value_Definition_Source: None Enumerated_Domain: Enumerated_Domain_Value: Widgeon Grass Enumerated_Domain_Value_Definition: Widgeon Grass Enumerated_Domain_Value_Definition_Source: None Attribute: Attribute_Label: Confidence Attribute_Definition: Level of confidence Attribute_Definition_Source: Michael Routhier, UNH, Geospatial Science Center Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: H Enumerated_Domain_Value_Definition: High Enumerated_Domain_Value_Definition_Source: None Enumerated_Domain: Enumerated_Domain_Value: M Enumerated_Domain_Value_Definition: Medium Enumerated_Domain_Value_Definition_Source: None Enumerated_Domain: Enumerated_Domain_Value: L Enumerated_Domain_Value_Definition: Low 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: Morse Hall, University of New Hampshire City: Durham State_or_Province: NH Postal_Code: 03824 Contact_Voice_Telephone: 603-862-1214 Contact_Facsimile_Telephone: 603-862-0188 Contact_Electronic_Mail_Address: granit@unh.edu Hours_of_Service: 9AM-5PM. EST 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: 0.7 Digital_Transfer_Option: Online_Option: Computer_Contact_Information: Network_Address: Network_Resource_Name: https://granit.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) Turnaround: Two weeks Technical_Prerequisites: None Metadata_Reference_Information: Metadata_Date: 20240415 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: Piscataqua Region Estuaries Partnership, University of New Hampshire Contact_Person: Kalle Matso Contact_Position: Science Program Manager Contact_Address: Address_Type: mailing and physical 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 Standard for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 Metadata_Time_Convention: local time