Citation:
Citation_Information:
Originator:
Grant McKown, Jackson Estuarine Laboratory, University of New Hampshire
Publication_Date: 20251118
Publication_Time: 010000
Title: Intertidal Rockweed Distribution
Geospatial_Data_Presentation_Form: vector digital data
Description:
Abstract:
The distribution of rockweed macroalgae was determined through a combination of remote sensing and field work in the Summer – Fall 2024. Preliminary rockweed distribution was calculated in Google Earth Engine with 2015 Leaf-off aerial imagery of New Hampshire (4-band) and National Agriculture Imagery Program (2012 – 2016, 4 – band). Manual thresholds of the non-difference brown algae index, non-difference water index, ratio of Red – Blue bands, and elevation (NAVD88 m) were used to differentiate rockweed from open water, bare mud, salt marsh, and overhanging tree canopy in the intertidal zone. Field inspections of the preliminary classification were conducted by boat along all tidal rivers in the estuary to remove erroneous classification of salt marsh and overhang tree canopy. See McKown et al., 2025 for detailed project description.
Purpose:
The dataset is intended to describe a conservative distribution of rockweed macroalgae (Fucus and Ascophyllum species) in the Great Bay Estuary, respective tidal rivers, and the Piscataqua River around Portsmouth, New Hampshire.
Status:
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -70.945895
East_Bounding_Coordinate: -70.682039
North_Bounding_Coordinate: 43.177657
South_Bounding_Coordinate: 43.022955
Keywords:
Theme:
Theme_Keyword_Thesaurus: None
Theme_Keyword: Rockweed
Theme_Keyword: Macroalgae
Theme_Keyword: Intertidal
Theme_Keyword: Eastern Oyster
Theme_Keyword: Mussel
Theme_Keyword: Great Bay Estuary
Theme_Keyword: Piscataqua River
Theme_Keyword: New Hampshire
Theme_Keyword: Maine
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Categories
Theme_Keyword: biota
Access_Constraints: None
Use_Constraints:
The data is intended for scientific research, policy decision making, and educational purposes. Proper citation is required for any use. Not for legal use.
Data_Set_Credit:
James McKown, Coastal Habitat Restoration Team, Jackson Estuarine Laboratory, University of New Hampshire
Native_Data_Set_Environment: Esri ArcGIS 13.0.2.36056