Great Bay Estuary Eelgrass, 2021

Identification_Information:

Citation:

Citation_Information:

Originator: Michael Routhier, UNH, Geospatial Science Center
Publication_Date: 20220802
Title: Great Bay Estuary Eelgrass, 2021
Geospatial_Data_Presentation_Form: vector digital data
Online_Linkage:

https://nhgeodata.unh.edu/nhgeodata/rest/services/Topical/CV_BiologyAndEcology/MapServer/30

Online_Linkage:

https://ftp.granit.sr.unh.edu/GRANIT_Data/Vector_Data/Biology_and_Ecology/eelgrass/2021/

Description:

Abstract:

The dataset shows the locations where eelgrass was observed during the 2021 field season 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 orthophotography collected using a UAV within Great Bay and Little Bay. Aerial orthophotography from the State of Maine was utilized to allow for photointerpretation of the Piscataqua River region, Portsmouth Harbor, Little Harbor, Newcastle, and Oriorne Point areas. Sentinel satellite imagery was also used to further complement these datasets to help within photointerpretation. Vertical UAV imagery was collected as five spectral bands inclusive of RGB, Red-Edge, and Near Infrared bands. Imagery was collected with varying 1.7 to 3.4 cm spatial resolutions based on 100 to 400 ft flight altitudes specific to FAA maximum flight restrictions around the Pease International Tradeport. Areal Vertical aerial photography was collected as for spectral bands inclusive of RGB and Near Infrared, with a nominal 1 foot spatial resolution. The Sentinel satellite imagery was acquired for the date of June 28th, 2021 with a nominal 10 meter spatial resolution. Environmental conditions included a low-sun angle, low tides, low cloud cover, calm winds, no preceding rain events, and low turbidity in the water column were maintained throughout the course of the survey. 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 GeoXT GPS unit.

Purpose:

The dataset was developed to monitor the distribution of eelgrass within the Great Bay Estuary over time. With the exception of 2018, 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: 20210601
Ending_Date: 20211001

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:

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_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: 20220801
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: 210

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: eelgrass2021
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: id
Attribute_Definition: Polygon id.
Attribute_Definition_Source: Geospatial Science Center
Attribute_Domain_Values:

Unrepresentable_Domain: Calculated value.

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

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: 2
Enumerated_Domain_Value_Definition: Eelgrass and Widgeon grass
Enumerated_Domain_Value_Definition_Source: None

Attribute_Domain_Values:

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

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: Eelgrass and Widgeon Grass
Enumerated_Domain_Value_Definition: Eelgrass and Widgeon Grass
Enumerated_Domain_Value_Definition_Source: None

Attribute_Domain_Values:

Enumerated_Domain:

Enumerated_Domain_Value: Widgeon Grass
Enumerated_Domain_Value_Definition: Widgeon Grass
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: 603-862-1792
Contact_Facsimile_Telephone: 603-862-0188
Contact_Electronic_Mail_Address: granit@unh.edu
Hours_of_Service: 8:30AM-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: 0.443

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) or order from web site (www.granit.unh.edu).

Turnaround: Two weeks

Technical_Prerequisites: None

Great Bay Estuary Eelgrass, 2021

Metadata: