LIS_Eelgrass_SAV (FeatureServer)

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Service Description: Eelgrass (Zostera marina) and submerged aquatic vegetation (SAV) data for Long Island Sound and assorted coastal rivers and embayments. Includes historic data from various sources as well as data collected from aerial photography and field surveys.

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Description: CT River SAV: From study " Distribution and Abundance of Submerged Aquatic Vegetation in the Lower Tidal Connecticut River." Barrett, et al., CTDEP Long Island Sound Reseach Fund. January 1997. Methods used followed the guidelines of NOAA Coastwatch Change Analysis Program (Dobson et al., 1994) and the Chesapeake Bay SAV studies (Orth, et al., 1990, 1992). Historic Eelgrass Points/Beds: Historic Eelgrass Beds and Points are 1:24,000-scale, feature-based layers that depict the locations of historic eelgrass beds (Zostera marina) in Long Island Sound as well as in other Rivers bays, harbors and waterbodies in Connecticut's coastal area. It also includes several points located along the north shore of Long Island. There are a total of 52 polygon features, all of which (except the Long Island points), are located within or east of the Niantic River. This layer does not represent current conditions. Rather, it depicts historic eelgrass bed locations that were observed and defined either cartographically or narratively over the course of many years and from various sources. The dates of each source's data collection are noted in the attribute table. Feature locations are inexact. Because of the variety of source maps and methods used for their automation, this information should be considered to have limited spatial accuracy and is appropriate for general uses only. The data was taken from maps of various scales and projections that were drawn between 1905 and 1996. In order to create a single polygon coverage, areas were considered to represent a maximum extent of eelgrass beds. There are a total of 131 point features, the majority of which are located east of the Connecticut River. Point features in this layer are compiled from two major sources: 1) the polygon feature label points in the Historic Eelgrass Beds polygon layer representing sources with a mapping component; and 2) additional points that were based on historic literature review that had no mapping component. Source information including source description and collection date for each point is described in the layer's table data. Feature locations are inexact. Because of the variety of source maps and methods used for their automation, this coverage should be considered to have limited spatial accuracy and is appropriate for general uses only. Actual data collection ranged from 1873 through 1996. These layers were published in 1997 and are not updated. They do not represent current conditions. Provided by the CT Dept of Energy & Environmental Protection. Observed Eelgrass 1993-95: Observed Eelgrass Beds is a 1:24,000 scale, polygon feature-based layer that depicts the locations of observed eelgrass beds in Long Island Sound, in major rivers, and within bays, harbors and other waterbodies along Connecticut's coast. The layer is based on information from the Eelgrass Sample Points layer. It represents conditions at a particular point in time (1993 to 1995). During the 1993-95 field seasons a team of researchers from the University of Connecticut Dept. of Ecology and Evolutionary Biology led by Charles Yarish, equipped with a Global Positioning System (GPS), SCUBA, and a 20' boat surveyed over 800 potential eelgrass locations. Their GPS coordinates and field notes were used to create a point coverage entitled Eelgrass Sample Points, which was plotted and checked on a 1:24000 scale base map of the Connecticut shore. These point locations, observations, and the nearshore bathymetry were then used to delineate areas representing both observed and potential eelgrass beds. Eelgrass beds were initially digitized at 1:24,000 scale, but have been edited and revised on screen at higher resolution. Keeping in mind the temporal and spatial variability of eelgrass, beds may vary in size, shape, and density from year to year. Feature locations may not always be exact due to equipment failure or lack of satellite reception. In those cases, points were estimated from field notes. It should be noted that the Observed Eelgrass Beds layer is not a complete dataset of all observed eelgrass sites in Connecticut and/or Long Island Sound. This layer was published in 1997 and is not updated. It does not represent current conditions. Provided by the CT Dept of Energy & Environmental Protection. 2002 Eelgrass: Interpretation and identification of Eelgrass beds located in the Long Island Sound Eastern Connecticut shoreline, Fishers Island NYS and the Northshore of Long Island NYS. Generated from 1:20,000 True Color Aerial Photography, 6/18/02. Field inspections conducted in later summer early fall of 2002 by boat-mounted underwater video. Citation: Tiner, R., H. Bergquist, T. Halavik, and A. MacLachlan. 2003. Eelgrass Survey for Eastern Long Island Sound, Connecticut and New York. U.S. Fish and Wildlife Service, National Wetlands Inventory Program, Northeast Region, Hadley, MA. National Wetlands Inventory report. 14 pp. plus Appendices. 2006 Eelgrass: This data layer was created by the USFWS National Wetlands Inventory, Region 5. Delineations of 2006 eelgrass beds were completed on the eastern Connecticut shoreline to the Rhode Island border. Fisher Island, Plum Island, and the northern shore of Long Island, New York were also included in this work. This dataset was developed for an ongoing eelgrass monitoring of the Long Island Sound. Funding was provided by the EPA, Region 2. Spring 2006 True Color aerial photography was taken at a scale of 1:20,000 and used for detemining location and delineation of eelgrass beds. Extensive field work was conducted by the USFWS Region 5 Southern Coastal Zone program in September, October and November, with 290 field sites. The 2006 photography was scanned and geo-rectified using 2004 ADS 1/2 meter true color imagery. Citation: Tiner, R., H. Bergquist, T. Halavik, and A. MacLachlan. 2007. 2006 Eelgrass Survey for Eastern Long Island Sound, Connecticut and New York. U.S. Fish and Wildlife Service, National Wetlands Inventory Program, Northeast Region, Hadley, MA. National Wetlands Inventory report. 24 pp. plus Appendix. 2009 Eelgrass: This dataset was developed for an ongoing eelgrass monitoring of the Long Island Sound. Funding was provided by the EPA, Region 2. This data layer was created by the Conservation Management Institute, Virginia Tech University for the USFWS National Wetlands Inventory, Region 5. The project area encompasses the eastern end of Long Island Sound, including Fishers Island and the North Fork of Long Island. It includes all coastal embayments and nearshore waters (i.e., to a depth of -15 feet at mean low water) bordering the Sound from Clinton Harbor in the west to the Rhode Island border in the east and including Fishers Island and the North Shore of Long Island from Southold to Orient Point and Plum Island. The study area includes the tidal zone of 18 sub-basins in Connecticut: Little Narragansett Bay, Stonington Harbor, Quiambog Cove, Mystic Harbor, Palmer-West Cove, Mumford Cove, Paquonock River, New London Harbor, Goshen Cove, Jordan Cove, Niantic Bay, Rocky Neck State Park, Old Lyme Shores, Connecticut River, Willard Bay, Westbrook Harbor, Duck Island Roads, and Clinton Harbor, and two areas in New York: Fishers Island and a portion of the North Shore of Long Island. Delineations of 2009 eelgrass beds were completed using 1:20,000 true color aerial photography flown at low tide on 7/14/2009 and 7/15/2009. Extensive field work was conducted by the USFWS Region 5 Southern New England-New York Bight Coastal Program Office in October, November, and December 2009 with 193 field sites checked. The 2009 photography was scanned and geo-rectified using 2006 NAIP 1 meter true color imagery. Citation: Tiner, R., K. McGuckin, M. Fields, N. Fuhrman, T. Halavik, and A. MacLachlan. 2010. 2009 Eelgrass Survey for Eastern Long Island Sound, Connecticut and New York. U.S. Fish and Wildlife Service, National Wetlands Inventory Program, Northeast Region, Hadley, MA. National Wetlands Inventory report. 16 pp. plus Appendix. 2012 Eelgrass: This dataset was developed for an ongoing eelgrass monitoring of the Long Island Sound. Funding was provided by the EPA, Region 2. This data layer was created by the Conservation Management Institute, Virginia Tech University for the USFWS National Wetlands Inventory, Region 5. The project area encompasses the eastern end of Long Island Sound, including Fishers Island and the North Fork of Long Island. It includes all coastal embayments and nearshore waters (i.e., to a depth of -15 feet at mean low water) bordering the Sound from Clinton Harbor in the west to the Rhode Island border in the east and including Fishers Island and the North Shore of Long Island from Southold to Orient Point and Plum Island. The study area includes the tidal zone of 18 sub-basins in Connecticut: Little Narragansett Bay, Stonington Harbor, Quiambog Cove, Mystic Harbor, Palmer-West Cove, Mumford Cove, Paquonock River, New London Harbor, Goshen Cove, Jordan Cove, Niantic Bay, Rocky Neck State Park, Old Lyme Shores, Connecticut River, Willard Bay, Westbrook Harbor, Duck Island Roads, and Clinton Harbor, and two areas in New York: Fishers Island and a portion of the North Shore of Long Island. Delineations of 2012 eelgrass beds were completed using 1:20,000 true color aerial photography flown at low tide on August 02, 2012. Earlier photo acquisition was not possible due to unfavorable weather conditions. Field work was conducted by the USFWS Region 5 Southern New England-New York Bight Coastal Program Office on October 02, 2012, prior to Hurricane Sandy. Only one day of field work was conducted due largely to the late season cquisition of imagery and unfavorable weather conditions. Citation: Tiner, R., K. McGuckin, and A. MacLachlan. 2013. 2012 Eelgrass Survey for Eastern Long Island Sound, Connecticut and New York. U.S. Fish and Wildlife Service, National Wetlands Inventory Program, Northeast Region, Hadley, MA. National Wetlands Inventory report. 20 pp. including Appendix. 2017 Eelgrass: Neckles et al. (2012) proposed a 3-tiered hierarchal strategy for mapping and monitoring SAV in estuaries of the northeastern U.S. The smallest scale of these tiers (Tier 1), utilizes true-color aerial photography whereby photo signatures of SAV are interpreted and delineated using orthophotography (aerial photographs with the distortion removed). Tier 2 surveys involve a stratified random sampling design whereby percent cover of SAV species is quantified. For the Tier 3 surveys, many metrics such as biomass and plant height are assessed along a transect. For the Long Island Sound study area, there have been four previous Tier 1 survey efforts (2002, 2006, 2009, and 2012) conducted in partnership with the US Fish and Wildlife Service and the LISS (Tiner et al., 2013). The goals of the 2017 Long Island Sound survey were similar to previous surveys: 1) conduct a comprehensive survey of SAV (primarily eelgrass) using similar methods as the previous surveys, and 2) examine broad trends of eelgrass in the Long Island Sound Study area. Digital four-band (true color and infra-red) aerial photographs were taken by a photogrammetry vendor on June 28th, 2017. The extent of the area photographed was based on recent presence of eelgrass in Long Island Sound (Tiner et al., 2013 , Connecticut Dept. of Env. Protection, 2007). Ground-truthing in the field was conducted by boat between September 8 and October 19, 2017. The presence of eelgrass was determined using a high-definition,digital underwater video camera linked to a GPS . Not all polygons were ground-truthed in 2017. Citation: Bradley, M., and Paton, S. 2018 (revised, September). Tier 1 2017 Mapping of Zoestra marina in Long Island Sound and Change Analysis. University of Rhode Island Data Center, Kingston, RI. 18 pp.

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