Description:
Abstract: Submerged aquatic vegetation (SAV) is an important habitat and site of primary production in many aquatic ecosystems but there was no baseline information on SAV extent or distribution in the tidal freshwater Hudson River. In 1994, a collaboration was initiated between the Institute of Ecosystem Studies (IES), the Hudson River National Estuarine Research Reserve/NYSDEC, the Cornell Laboratory for Environmental Applications of Remote Sensing (CLEARS), now the Cornell Institute for Resource Information Systems (IRIS) <
http://www.css.cornell.edu/iris/>. In addtion, the New York Sea Grant, the Hudson River Estuary Program, and the National Oceanic and Atmospheric Administration (NOAA) are identified as partners. These groups provided diverse expertise to enable the first broad delimitation of SAV in the Hudson.
Purpose: The project was undertaken in two separate time periods with different sources of funding. In 1995, Phase I (Hyde Park to Castleton) was initiated with National Oceanic and Atmospheric Association and Hudson River Foundation funds. Subsequently in 1997, the remaining portions (Hastings to Hyde Park and Castleton to Troy) were undertaken in Phase II with New York. State Environmental Protection Funds through the Hudson River Estuary Program.
Supplemental_Information: High quality, true color aerial photographs were acquired for Phase I on August 9, 1995 and Phase II on July 20, August 7 and August 18 in 1997 by AeroGraphics, Inc. of Bohemia, New York. Photographs were acquired with 60% forward lap and 30% side lap, at the nominal scale of 1:14,400 under ideal conditions within one hour of low tide and clear atmospheric conditions. Flight and mapping criteria followed the 1994 NOAA C-CAP protocols for SAV mapping. Stereoscopic aerial photographic coverage was available for the entire study area. The effective area of alternate aerial photographs was established and delineated on 3 mil matte acetate photo overlays. Major tributaries were not mapped with the exception of Schodack Creek. Shoreline Coverage-- The four-category classification system was developed through consultations among IES, HRNERR and IRIS. The four categories (numerical codes) are Open Water (VEGCODE=0), Upland/Intertidal (VEGCODE=1); Vallisneria americana (VEGCODE=2), and Trapa natans (VEGCODE=3). Of primary interest is Vallisneria americana, the predominant species of SAV. It is important to note that our Upland/Intertidal category includes intertidal marshes and mudflats which were largely exposed at time of photography. OW - Open Water VEGCODE=0" - Water areas including the Hudson River, tributary rivers, bays, coves with no indicators of submerged rooted vegetation, upland vegetation or dry land. UP/INT - Upland/Intertidal VEGCODE=1 - Dry land with or without upland vegetation or intertidal marsh vegetation. VA - Vallisneria americana (water or wild celery, tape grass) VEGCODE=2 - Beds of Vallisneria americana as well as beds of mixed vegetation including Vallisneria americana. TN - Trapa natans (water chestnut, water nut) VEGCODE=3 - Beds of Trapa natans, rooted with floating leaves. Linear Coverage-- During ground-truthing of polygon beds north of Albany, observations were made of frequent occurrences of very narrow linear beds of Vallisneria located adjacent to the shoreline. These features generally appeared to be in the two-to-three meter width size, and because they did not provide a signature were not visible on the color aerial photographs. In some instances, the plants were over-shadowed by tree cover along the shoreline. These features were subsequently mapped from the ground. Mapping of linear features, grab samples and GPS quality control functions resulted from a collaboration between Cornell IRIS and the Institute of Ecosystems Studies (IES). IES performed digitization; data merging and conversion performed by IRIS. Data have been converted from NAD27 to NAD83.
Keywords:
Theme:
Theme_Keyword_Thesaurus: LCSH
Theme_Keyword: Marine plants
Theme_Keyword: Seagrasses
Theme_Keyword: Estuarine plants
Theme_Keyword: Aquatic plants
Theme_Keyword: Marine plants
Theme_Keyword: American wild celery
Theme_Keyword: Water chestnut
Theme_Keyword: Aquatic weeds
Theme:
Theme_Keyword_Thesaurus: none
Theme_Keyword: Vallisneria americana
Theme_Keyword: Trapa natans
Theme_Keyword: Submerged aquatic vegetation
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Category
Theme_Keyword: biota
Theme_Keyword: environment
Theme_Keyword: inlandWaters
Theme_Keyword: oceans
Theme:
Theme_Keyword_Thesaurus: CUGIR Category
Theme_Keyword: biology
Theme_Keyword: environment
Theme_Keyword: inland waters
Theme_Keyword: oceans
Place:
Place_Keyword_Thesaurus: LCSH
Place_Keyword: Hudson River (N.Y. and N.J.)
Place_Keyword: Hudson River Estuary (N.Y. and N.J.)
