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SDE Feature Class
Tags
aquaculture, Ostrea edulis, biosphere, sea scallop, american oyster, atlantic surf, razor clam, 40000, molluscan shellfish, Maine, commodities, Spisula solidissima, biology, blue mussel, Ensis directus, aquatic habitat, european oyster, Mya arenaria, Crassastrea virginica, Placopectin magellanicus, marine biology, marine environment monitoring, coastal, hard clam, Mytilus edulis, shellfish, molluscan, Gulf of Maine, softshell clam, habitat, oceans, Mercenaria mercenaria
Though primarily based on harvestable locations, shellfish species distributions are helpful tools for planning activities. Baseline data of shellfish species distributions in Maine provides a foundation for future data updates. Data at this scale is suitable for use in generalized studies and local planning.
Molluscan Shellfish are polygon datasets that contain distribution information for the molluscan shellfish species; sea scallop (Placopectin magellanicus), american oysters (Crassostrea virginica), atlantic surf clams (Spisula solidissima), blue mussels (Mytilus edulis), european oysters (Ostrea edulis), hard clams (Mercenaria mercenaria), razor clam (Ensis directus) and softshell clams (Mya arenaria) 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, Acres and Source. A COMMENT field indicates sea scallop locations obtained from DMR sea scallop tow survey data generated during 2005 - 2007.
Credit should always be given to the data source and/or originator when the data is transferred or printed.
Users must assume responsibility in determining the usability of this data for their purposes. Digital maps retain the accuracy of their source materials. The best use of data mapped at scales of 1:500,000 and 1:250,000 is in statewide planning and studies; at 1:100,000 in regional planning and studies; at 1:62,500 and 1:24,000 in detailed studies and local planning; and at 1:12,000 and 1:5,000 or larger scales in parcel level studies and detailed local planning. In the use of Maine GIS data, please check sources, scale, accuracy, currentness and other available information. Please confirm that you are using the most recent copy of both data and metadata from the Maine GIS Data Catalog.
Extent
West | -70.866830 | East | -68.703043 |
North | 44.396131 | South | 43.096281 |
Maximum (zoomed in) | 1:5,000 |
Minimum (zoomed out) | 1:50,000 |
These layers may not be current or complete, as shellfish distributions could change over time and portions of the Maine coast may not have been included.
Credit should always be given to the data source and/or originator when the data is transferred or printed.
Users must assume responsibility to determine the usability of this data for their purposes. Although these data have been processed successfully on a computer system at the Maine Office of Geographic Information Systems, no warranty expressed or implied is made by MEGIS regarding the utility of the data on any other system, nor shall the act of distribution constitute any such warranty. Neither the Maine Office of Geographic Information Systems, nor any of its contributors, is liable for misuse of the data, for damage, for transmission of viruses, or for computer contamination through the distribution of these data sets.
Users must assume responsibility to determine the usability of this data for their purposes.
Secondary distribution by permission only. Please see Maine Office of Geographic Information Systems (MEGIS) license agreement at <http://megis.maine.gov/>. Any secondary distribution must have this documentation appended.
Users must assume responsibility in determining the usability of this data for their purposes. Digital maps retain the accuracy of their source materials. The best use of data mapped at scales of 1:500,000 and 1:250,000 is in statewide planning and studies; at 1:100,000 in regional planning and studies; at 1:62,500 and 1:24,000 in detailed studies and local planning; and at 1:12,000 and 1:5,000 or larger scales in parcel level studies and detailed local planning. In the use of Maine GIS data, please check sources, scale, accuracy, currentness and other available information. Please confirm that you are using the most recent copy of both data and metadata from the Maine GIS Data Catalog.
source dates
publication date
polygon attribute table
Environmental Systems Research Institute, Inc. (ESRI)
Internal feature number.
Esri
Area in acres
County name
The name of the county in which the selected feature's town is located. The county was determined using DeLorme's "Maine Atlas and Gazetteer" county map
Chart number of basemap
Electronic NOAA chart that contains the feature. Scales vary from 1:20,000 to 1:80,000
Internal feature number.
ESRI
Feature geometry.
ESRI
Contributor
The source of first-hand knowledge of the approximate location of the feature. The catagories of sources include: town officials, harvesters, Harbormasters, MEDMR biologists, MEDMR specialists or MEDMR scientists. Where two sources indicated the same feature location, the most "hands-on" source category was listed as the source. Some features are composites from several sources, and show the most extensive boundary indicated by the multiple sources
Species common name
The molluscan bivalve known as (wil insert scientific name here)
Town name
The identity of the town was derived from MEDMR shapefile "towns-24k". Town boundaries were determined using shapefile "metwp24" from the MEGIS data catalog
The date the feature's boundaries were last changed
Molluscan Shellfish are polygon datasets that contain distribution information for the molluscan shellfish species; sea scallop (Placopectin magellanicus), american oysters (Crassostrea virginica), atlantic surf clams (Spisula solidissima), blue mussels (Mytilus edulis), european oysters (Ostrea edulis), hard clams (Mercenaria mercenaria), razor clam (Ensis directus) and softshell clams (Mya arenaria) 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, Acres and Source. A COMMENT field indicates sea scallop locations obtained from DMR sea scallop tow survey data generated during 2005 - 2007.
Though primarily based on harvestable locations, shellfish species distributions are helpful tools for planning activities. Baseline data of shellfish species distributions in Maine provides a foundation for future data updates. Data at this scale is suitable for use in generalized studies and local planning.
These layers may not be current or complete, as shellfish distributions could change over time and portions of the Maine coast may not have been included.
publication date
Secondary distribution by permission only. Please see Maine Office of Geographic Information Systems (MEGIS) license agreement at <http://megis.maine.gov/>. Any secondary distribution must have this documentation appended.
Users must assume responsibility in determining the usability of this data for their purposes. Digital maps retain the accuracy of their source materials. The best use of data mapped at scales of 1:500,000 and 1:250,000 is in statewide planning and studies; at 1:100,000 in regional planning and studies; at 1:62,500 and 1:24,000 in detailed studies and local planning; and at 1:12,000 and 1:5,000 or larger scales in parcel level studies and detailed local planning. In the use of Maine GIS data, please check sources, scale, accuracy, currentness and other available information. Please confirm that you are using the most recent copy of both data and metadata from the Maine GIS Data Catalog.
Credit should always be given to the data source and/or originator when the data is transferred or printed.
Fields named: Town, County, Species, NOAA_Chart, Updated, Shape, and Source have been maintained and are complete. Other fields may not be complete.
molluscan shellfish is a polygon dataset that provides distribution information for molluscan shellfish for the coast of Maine.
The dataset is updated on an irregular schedule.
The data were compiled on a 1:40000 scale base with a horizontal accuracy +/- 70 feet or 20 meters (based on National Map Accuracy Standards). Polygons are based on locations indicated by town officials, harvesters, Harbormasters, DMR biologists, DMR specialists or DMR scientists from February 2008 to May 2009.
Local knowledge of molluscan shellfish species locations along the Maine coast
Base information to which shellfish polygons were referenced.
Sea scallop tow survey data insertion- Sea scallop tow survey data for years 2005 through 2007 were extracted from the MEDMR's MARVIN database, and placed into a Mircosoft Excel spreadsheet format. This spreadsheet was converted into a Microsoft Access database file, and imported into the ArcGIS project file. The X -Y coordinates were plotted in ArcMap, using geographic coordinate system "North American Datum 1983". Polygons were drawn around points containing reported quantities of at least one sea scallop. There were two points in the 2005 sea scallop data that were located over a land mass: they contained reported quantities of zero scallops, and they were excluded from the ssea scallop shapefile. There were two points in the 2006 sea scallop data that were south of Mount Desert Island. Since there was no reference town in the "towns-24K" file to correspond to these points, they were excluded from the sea scallop shapefile.
Map construction- Series of paper maps were created for each coastal town, depicting the nearshore coastline. These maps were created using electronic National Oceanic and Atmospheric Administration (NOAA) charts in ArcMap 9.2, which were then converted to .PDF documents. Landmarks were used as reference points from one map to the next, so participants could stay oriented throughout the map series.
Data collection- Paper map series were sent to town officials, harvesters, Harbormasters, MEDMR specialists, MEDMR scientists and MEDMR biologists. All recipients were asked to mark molluscan shellfish resource locations, observed within the last two to three years, on the maps. They could use a different pen color for each species, or write the species name in the marked areas. They were asked to send the maps back to the project manager. Two people chose to mark resources on paper NOAA charts, which were returned to the project manager. Some people marked only commercially viable shellfish locations, and other people marked all observed locations of shellfish resources
Digitization of data- Marked maps were scanned into Adobe Acrobat 6.0 Professional, and a .PDF document was created. The .PDF documents were georeferenced to the appropriate electronic NOAA chart, and polygons were created to encompass each marked location of molluscan shellfish. Where multiple sources indicated a specific location, the most "hands-on" source category was used as the source. Some polygons are composites from several sources, and show the largest boundary indicated by the multiple sources
Data review- Michelle Mason Webber fixed town coding errors. Seth Barker removed overlapping polygons, created a geodatabase, and applied topology to the shellfish layers
Metadata imported.
Dataset copied.
Users must assume responsibility to determine the usability of this data for their purposes. Although these data have been processed successfully on a computer system at the Maine Office of Geographic Information Systems, no warranty expressed or implied is made by MEGIS regarding the utility of the data on any other system, nor shall the act of distribution constitute any such warranty. Neither the Maine Office of Geographic Information Systems, nor any of its contributors, is liable for misuse of the data, for damage, for transmission of viruses, or for computer contamination through the distribution of these data sets.
These data are available to Internet browsers for download from the Maine GIS Internet Data Catalog. Data available from this website is in .zip compressed format. WinZip is a Windows based, PKZip-compatible compression utility. You will need a program like this to extract the data. A link to a trial copy WinZip software is available at http://megis.maine.gov/links/. If you are not already a GIS user, free software for viewing these files is available from Environmental Systems Research Institute, Inc. (ESRI). See http://megis.maine.gov/links/ for a link to ArcExplorer 9.x .
Users must assume responsibility to determine the usability of this data for their purposes.
Please contact the Maine Office of GIS (MEGIS) for access instructions.