Identification_Information: Citation: Citation_Information: Originator: Dr. Frederick Short, University of New Hampshire, Durham, NH Publication_Date: 19950630 Title: Great Bay Estuary Eelgrass, 1994 Geospatial_Data_Presentation_Form: vector digital data Online_Linkage: Description: Abstract: Note that yearly variations in collection methods exist. Following is a summary of methods that have been used. The dataset shows the locations where eelgrass was observed in the Great Bay Estuary based on low-altitude aerial surveillance. 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. Aerial photographs are taken of the study area at 3000 feet at low spring tide with roughly 60% overlap on a calm day without preceding rain events and when the sun is at a low angle to minimize reflection (between 7 am and 10 am). Photographs are taken in late summer, usually late August or early September, depending on tides and weather, to reflect the maximum eelgrass annual biomass. 35 mm film (ASA 200) or a digital camera is used to acquire the images. Typically 300 images are needed to cover the entire Great Bay Estuary. The orientation of the photographs is near-vertical. This is a slight deviation from the NOAA Coastal Change Analysis Program protocol, but follows a published method (Short and Burdick, 1986). The photographs, in the form of 35mm slides or digital computer images, are projected on a screen and the eelgrass images are transferred to a base map. These maps are then digitized using GIS software. 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. Samples are collected with an eelgrass sampling hook. Positions are determined using GPS. The ground-truth surveys assess 10-20% of the eelgrass beds mapped in the estuary. The aerial survey is completed yearly. The first survey in the series was completed in 1986. 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 quality assurance project plan is available at: http://prep.unh.edu/resources/qapps/unh_eelgrass_zostera-qapp-unh&des-10.pdf. Time_Period_of_Content: Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 19940801 Ending_Date: 19940930 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 is a subset of spatial databases developed by the University of New Hampshire 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, tax map and lot information, 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: Phil Trowbridge, P.E. Contact_Organization: New Hampshire Department of Environmental Services Contact_Position: Coastal Scientist Contact_Address: Address_Type: Mailing and Physical Address Address: 29 Hazen Drive, PO Box 95 City: Concord State_or_Province: New Hampshire Postal_Code: 03302 Contact_Voice_Telephone: 603-271-3503 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. Samples are collected with an eelgrass sampling hook. Positions are determined using GPS. The ground-truth surveys assess 10-20% of the eelgrass beds mapped in the estuary. Overlapping polygon areas are identified and removed using a topology rule. Completeness_Report: The dataset is complete. There are no known omissions. Lineage: Source_Information: Source_Time_Period_of_Content: Source_Currentness_Reference: Publication Date Time_Period_Information: Range_of_Dates/Times: Beginning_Date: 19940801 Ending_Date: 19940930 Type_of_Source_Media: Digital Source_Citation_Abbreviation: UNH Source_Contribution: UNH Source_Citation: Citation_Information: Originator: Dr. Frederick Short, University of New Hampshire, Durham, NH Publication_Date: 19950630 Title: Great Bay Eelgrass 1994 Process_Step: Process_Description: The photographs, in the form of 35mm slides or digital computer images, are projected on a screen and the eelgrass images are transferred to a base map by hand (i.e., the polygons are hand-drawn on a hardcopy map of the estuary). The polygons on the hardcopy maps are later digitized. Process_Date: 19950630 Process_Contact: Contact_Information: Contact_Person_Primary: Contact_Person: Phil Trowbridge Contact_Organization: New Hampshire Department of Environmental Services Contact_Position: Coastal Scientist Contact_Address: Address_Type: Mailing and Physical Address Address: 29 Hazen Drive, PO Box 95 City: Concord State_or_Province: New Hampshire Postal_Code: 03302 Contact_Voice_Telephone: 603-271-8872 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: 80 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: eelgrass1994 Entity_Type_Definition: Each polygon of eelgrass habitat is assigned an attribute in the density field of the attribute table. The values in the density field are qualitative assessments of the eelgrass density in each polygon. Entity_Type_Definition_Source: NHDES 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: AREA Attribute_Definition: Area of the eelgrass in square feet. Attribute_Definition_Source: UNH Attribute_Domain_Values: Unrepresentable_Domain: Calculated value Attribute: Attribute_Label: PERIMETER Attribute_Definition: Perimeter of the eelgrass area in feet. Attribute_Definition_Source: UNH Attribute_Domain_Values: Unrepresentable_Domain: Calculated value. Attribute: Attribute_Label: DENSITY Attribute_Definition: Qualitative assessments of the eelgrass density in each polygon Attribute_Definition_Source: UNH Attribute_Domain_Values: Enumerated_Domain: Enumerated_Domain_Value: d Enumerated_Domain_Value_Definition: Dense. Eelgrass covers 90-100% of the bottom. The bottom is not visible in the aerial photos. The shoot density or biomass level for eelgrass of this density is approximately 250 grams per square meter. Enumerated_Domain_Value_Definition_Source: UNH Enumerated_Domain: Enumerated_Domain_Value: sb Enumerated_Domain_Value_Definition: Some bottom. Eelgrass covers 60-90% of the bottom. Some bottom is visible in the aerial photos but the majority is covered by eelgrass. The shoot density or biomass level for eelgrass of this density is approximately 85 grams per square meter. Enumerated_Domain_Value_Definition_Source: UNH Enumerated_Domain: Enumerated_Domain_Value: h Enumerated_Domain_Value_Definition: Half. Eelgrass covers 30-60% of the bottom. Approximately half the bottom is visible in the aerial photos. The shoot density or biomass level for eelgrass of this density is approximately 55 grams per square meter. Enumerated_Domain_Value_Definition_Source: UNH Enumerated_Domain: Enumerated_Domain_Value: p Enumerated_Domain_Value_Definition: Partial. Eelgrass covers 10-30% of the bottom. Eelgrass is present but the majority of the bottom is still visible in the bed. The shoot density or biomass level for eelgrass of this density is approximately 25 grams per square meter. Enumerated_Domain_Value_Definition_Source: UNH Enumerated_Domain: Enumerated_Domain_Value: pr Enumerated_Domain_Value_Definition: Present. Eelgrass is present but the density could not be determined. Enumerated_Domain_Value_Definition_Source: UNH Enumerated_Domain: Enumerated_Domain_Value: unk Enumerated_Domain_Value_Definition: Present. Eelgrass is present but the density could not be determined. Enumerated_Domain_Value_Definition_Source: UNH Enumerated_Domain: Enumerated_Domain_Value: r Enumerated_Domain_Value_Definition: Ruppia. Ruppia maritima is a different species of submerged aquatic vegetation than the Zostera marina that is mapped for this program. Ruppia can be found in the Great Bay Estuary at low levels, particularly in association with salt marsh pannes and in the upper reaches of the estuary. Ruppia was mapped if it appeared in large beds in parts of the tributaries where eelgrass could be expected. Enumerated_Domain_Value_Definition_Source: UNH Enumerated_Domain: Enumerated_Domain_Value: NULL Enumerated_Domain_Value_Definition: No eelgrass. Polygon represents an island or area without eelgrass. Enumerated_Domain_Value_Definition_Source: UNH Attribute: Attribute_Label: HECTARES Attribute_Definition: Eelgrass area in hectares. Attribute_Definition_Source: UNH Attribute_Domain_Values: Unrepresentable_Domain: Calculated value. Attribute: Attribute_Label: ACRES Attribute_Definition: Acreage of the eelgrass area. Attribute_Definition_Source: UNH Attribute_Domain_Values: Unrepresentable_Domain: Calculated value. Attribute: Attribute_Label: YEAR_ Attribute_Definition: The year that the data was collected. Attribute_Definition_Source: UNH Attribute_Domain_Values: Unrepresentable_Domain: Calculated value. Distribution_Information: Distributor: Contact_Information: Contact_Organization_Primary: Contact_Organization: Complex 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. Complex Systems Research Center, under contract to the NH Office of Energy and Planning, and in consultation with cooperating agencies, maintains a continuing program to identify and correct errors in these data. OEP, CSRC, 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.sr.unh.edu). Turnaround: Two weeks Technical_Prerequisites: None Metadata_Reference_Information: Metadata_Date: 20120522 Metadata_Contact: Contact_Information: Contact_Organization_Primary: Contact_Organization: NH Department of Environmental Services Contact_Person: George Hastings Contact_Address: Address_Type: mailing and physical address Address: 29 Hazen Drive, PO Box 95 City: Concord State_or_Province: New Hampshire Postal_Code: 03302 Contact_Voice_Telephone: 603-271-3503 Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata Metadata_Standard_Version: FGDC-STD-001-1998 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