Hard_clams is a REGIONS dataset and contains distribution information for hard clams (Mercenaria mercenaria), also called "quahogs", for the coast of Maine . Polygons are based on locations indicated by town officials, harvesters, Harbormasters, DMR biologists, DMR specialists or DMR scientists from February 2008 to May 2009. POLYGON codes include: Town, County, Species, NOAA_Chart, Updated, Shape, ACRES, OBJECTID, SHAPE_AREA, SHAPE_LEN, and Source.
NOAA's Office of Coast Survey (OCS) is responsible for generating the Three Nautical Mile Line, Territorial Sea, Contiguous Zone, and Exclusive Economic Zone (EEZ). Traditionally, these maritime limits have been generated by hand from the low water line depicted on paper, U.S. nautical charts. Upon final approval by the U.S. Baseline Committee, these legally-binding maritime limits are applied to the next edition of nautical charts produced by the Marine Chart Division of OCS.
Due to new cartographic production processes and the availability of digital products such as Electronic Navigational Charts (ENCs), the Office of Coast Survey (OCS) is generating more accurate, digital maritime limits. Through the use of Geographic Information Systems (GIS) software such as CARIS' LOTS and ESRI's ArcGIS, the latest vector representations of these limits will be available to NOAA cartographers and the public.
To create digital limits, the charted low water line is digitized from the largest-scale raster nautical charts and used as input to CARIS' LOTS: Limits and Boundaries software for the designation of a baseline. Other parts of the EEZ include maritime boundary agreements and/or unilateral claims as noted in Federal Register Notice, Volume 60, No. 163, Wednesday August 23, 1995. Once the limits are created, they are exported to a shapefile using CARIS' "Import SHP File" utility.
Digital limits of the Exclusive Economic Zone for the Atlantic coast of the United States are contained within a zipped file. Within the zipped file is a shapefile and a text file detailing the individual coordinates.