Eelgrass Beds 93-95 Set

Eelgrass Beds 93-95 Set: Eelgrass Sample Points is a 1:24,000-scale, point feature-based layer that depicts the locations where eelgrass (Zostera marina) was either observed or where a location would be potentially favorable for future eelgrass growth. Sample points were taken along Connecticut's coast in Long Island Sound, and in major bays, harbors and rivers along the shoreline. The point features in this layer were compiled from field research using global positioning system (GPS) equipment. Feature locations were not always exact due to equipment failure or lack of satellite reception. In those cases, points were estimated from field notes. Some point locations were corrected based on field notes or hydrography and bathymetry conditions at the sample point location. The number of field points that were altered were as follows: In 1993, 32 of 290 points (11%); in 1994, 93 of 454 points (20%); in 1995, 37 of 105 points (35%). Data compilation occurred on 17 days between 7/21/1993 and 11/16/1995; exact dates of each source's data collection are noted in the attribute table. A total of 849 point locations were surveyed. The westernmost point is Frash Pond in Stratford, Connecticut and the easternmost point is the Pawcatuck River on the Connecticut/Rhode Island Border. Eelgrass was found at 484 locations and was described as either high, medium, or low density, or simply as present or absent. Eelgrass was absent at 365 locations. Publication of the datalayer was in 1997. This layer is not updated. This layer does not represent current conditions. 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. There are 101 polygon features representing observed eelgrass beds in this layer. Geographic locations are as follows: westernmost areas: Clinton Harbor; easternmost areas: Little Narragansett Bay, Rhode Island waters. Observed beds range in size from .003 acre (131 sq. ft.) to 49 acres (2,136,608 sq. ft.). The total area of observed beds is 632.6 acres. Potential Eelgrass Beds is a 1:24,000 scale, polygon feature-based layer that depicts the locations of potential 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 Observed Eelgrass Beds and Eelgrass Sample Points layers. 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. Potential beds, where not individually delineated, were created by buffering observed beds a distance of 33 feet (10 meters). These buffered polygons were intersected with buffered (distance of 5 ft.) shoreline arcs to keep potential polygons a minimum distance off the shoreline. These potential beds are considered to be areas where eelgrass is likely to spread to under ideal conditions, where eelgrass may exist in small isolated patches, where eelgrass may exhibit high temporal variability, or perhaps where restoration projects could be undertaken. 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 Potential Eelgrass Beds layer is not a complete dataset of all potential 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. There are 67 polygon features representing potential eelgrass beds in this layer. Geographic locations are as follows: westernmost areas: Clinton Harbor; easternmost areas: Little Narragansett Bay, Rhode Island waters. Potential beds range in size from .179 acre (318 sq. ft.) to 471 acres (20,551,582 sq. ft.). Potential beds contain 0 to 9 observed beds, and from 0 to 88.1% area covered by observed beds. The total area of potential beds is 2,196 acres.