The distribution of rockweed macroalgae was determined through a combination of remote sensing and field work in the Summer \u2013 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 \u2013 2016, 4 \u2013 band). Manual thresholds of the non-difference brown algae index, non-difference water index, ratio of Red \u2013 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.<\/p>", "summary": "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.", "title": "CV_IntertidalRockweedDistribution", "tags": [ "CV_IntertidalRockweedDistribution", "MapServer" ], "type": "Feature Service", "typeKeywords": [ "ArcGIS", "ArcGIS Server", "Data", "Feature Access", "Feature Service", "providerSDS", "Service" ], "thumbnail": "thumbnail/thumbnail.png", "url": "", "extent": [ [ -70.9101891779241, 43.0405223386255 ], [ -70.6820390343628, 43.1776567196768 ] ], "minScale": 0, "maxScale": 1.7976931348623157E308, "spatialReference": "NAD_1983_StatePlane_New_Hampshire_FIPS_2800_Feet", "accessInformation": "James McKown, Coastal Habitat Restoration Team, Jackson Estuarine Laboratory, University of New Hampshire", "licenseInfo": "
The data is intended for scientific research, policy decision making, and educational purposes. Proper citation is required for any use. Not for legal use.<\/p>", "portalUrl": "" }