20230119 22113800 1.0 FGDC CSDGM Metadata FALSE Seagrass2022 002 399664.085276 432045.135718 4825051.925239 4864705.846316 1 0.744 Projected GCS_North_American_1983 Linear Unit: Meter (1.000000) NAD_1983_UTM_Zone_19N <ProjectedCoordinateSystem xsi:type='typens:ProjectedCoordinateSystem' xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' xmlns:xs='http://www.w3.org/2001/XMLSchema' xmlns:typens='http://www.esri.com/schemas/ArcGIS/3.3.0'><WKT>PROJCS["NAD_1983_UTM_Zone_19N",GEOGCS["GCS_North_American_1983",DATUM["D_North_American_1983",SPHEROID["GRS_1980",6378137.0,298.257222101]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Transverse_Mercator"],PARAMETER["False_Easting",500000.0],PARAMETER["False_Northing",0.0],PARAMETER["Central_Meridian",-69.0],PARAMETER["Scale_Factor",0.9996],PARAMETER["Latitude_Of_Origin",0.0],UNIT["Meter",1.0],AUTHORITY["EPSG",26919]]</WKT><XOrigin>-5120900</XOrigin><YOrigin>-9998100</YOrigin><XYScale>10000</XYScale><ZOrigin>-100000</ZOrigin><ZScale>10000</ZScale><MOrigin>-100000</MOrigin><MScale>10000</MScale><XYTolerance>0.001</XYTolerance><ZTolerance>0.001</ZTolerance><MTolerance>0.001</MTolerance><HighPrecision>true</HighPrecision><WKID>26919</WKID><LatestWKID>26919</LatestWKID></ProjectedCoordinateSystem> 20250603 15124200 20250603 15124200 150000000 5000 FGDC Esri ArcGIS 13.3.4.52636 Seagrass2022 1 -70.249974 -69.841610 43.932335 43.571679 The Maine Department of Environmental Protection (MEDEP), Bureau of Water Quality, Division of Environmental Assessment contracted with Normandeau Associates, Inc. to map seagrasses in the Casco Bay area between Cape Elizabeth and Cape Smll in Phippsburg. This dataset contains the mapped seagrass polygons and will be used to compare seagrass locations and densities over time. <DIV STYLE="text-align:Left;">This dataset contains the seagrass beds delineated in 2022 in Casco Bay, from Cape Elizabeth to Cape Small in Phippsburg. Polygons were screen digitized from aerial imagery flown at low tide on July 16th, 2022. Imagery was captured using a Vexcel Eagle 80-mm Mark 3 aerial camera mounted on a fixed wing aircraft and flown at an elevation of approximately 9,500 feet. Polygons were refined based on field verification efforts that took place between August 29 and September 27, 2022. Field verification was carried out on foot by Old Brunswick Road at the New Meadows River and by boat using a Maine DEP vessel (20-foot Maritime Skiff with a 115 horse outboard motor), Ocean Systems High-Definition (HD) underwater video camera and SeaViewer 950 Sea-Drop Analog underwater video camera, and Eos Positioning Systems Arrow Gold GNSS GPS systems that pair wirelessly to Android powered ruggedized field tablets capable of submeter accuracy. Each seagrass bed is named by sequential number moving from southwest to northeast along the coast, then back southeast along the islands, which is provided in the ‘Name’ column. These beds are further divided into polygons by percent cover. Polygons are labeled with a unique identifier consisting of sequential numbers in the ‘Id’ column. A singular bed can consist of several Ids. Percent cover categories and percentages are based on those established by Orth et al. (1991), where 1=0-10% cover (very sparse), 2=10-40% cover (sparse), 3=40-70% cover (moderate), 4=70-100% cover (dense). This seagrass polygon shapefile also contains fields for whether the bed was field verified in 2022 (Y=yes or N=no) and whether there is corresponding underwater video footage (Y=yes, N=no). Field verified beds were verified only in part, meaning one or more transects were placed along the perimeter of the bed to confirm seagrass presence and aerial signatures; bed boundaries were not verified in their entirety. Field verification refers to whether the bed (Name field) was visited, it does not account for individual parts of the bed (Id field) with differing cover classes, though often verification occurred in more than one cover class per bed. Underwater video is present for most of the field verified beds but is lacking in some areas due to video transfer errors. The video column corresponds to the named underwater video file, which corresponds to transect name. Species and comment fields are also incorporated in this dataset. Species are only noted if directly observed by underwater video or by visual observations in shallow water. Widgeon grass was observed only in the New Meadows River area off of Old Brunswick Road from samples washed up near shore.<DIV></DIV></DIV> Seagrass mapping was produced for the State of Maine Department of Environmental Protection. Orthophotos for this effort were acquired by James W. Sewall and Bluesky Geospatial was subcontracted for aerial imagery acquisition. Normandeau Associates, Inc. was the primary contractor for seagrass delineation. Maine Casco Bay Cape Elizabeth South Portland Portland Falmouth Yarmouth Freeport Harpswell Sebascodegan Island West Bath Sebasco Phippsburg Long Island Chebeague Island Cousins Island Maquoit Bay seagrass eelgrass widgeon grass field verification File Geodatabase Feature Class 0.744 dataset EPSG 6.11(3.0.1) 0 Simple FALSE 0 TRUE FALSE Seagrass2022 Feature Class 0 OBJECTID OBJECTID OID 4 0 0 Internal feature number. Esri Sequential unique whole numbers that are automatically generated. Shape Shape Geometry 0 0 0 Feature geometry. Esri Coordinates defining the features. Id Id Integer 4 0 0 Name Name String 10 0 0 Acres Acres Double 8 0 0 Hectares Hectares Double 8 0 0 Orth_Cover Orth_Cover Integer 4 0 0 Cover_Pct Cover_Pct String 10 0 0 Field_Ver Field_Ver String 1 0 0 Video_YN Video_YN String 1 0 0 Video Video String 50 0 0 Comment Comment String 75 0 0 Species Species String 50 0 0 Shape_Length Shape_Length Double 8 0 0 Length of feature in internal units. Esri Positive real numbers that are automatically generated. Shape_Area Shape_Area Double 8 0 0 Area of feature in internal units squared. Esri Positive real numbers that are automatically generated. 20250603