Eelgrass2010

Identification Information

Citation Information

Originator	Seth Barker, Maine Department of Marine Resources, GIS Manager
Publication Date	20120524
Publication Time	000000
Title	Eelgrass2010
Edition	Final
Geospatial Data Presentation Form	vector digital data
Series Name	Maine Coastal Eelgrass
Other Citation Details	This is the second mapping of distribution. The previous mapping took place from 1992 to 1997.

Abstract

Maine's eelgrass meadows form an important marine and estuarine coastal aquatic habitat for the state. Along with other plants, eelgrass forms the base of food production in the sea. Eelgrass provides shelter for juvenile fish, and invertebrates, is a site for primary settlement of the larvae of some bivalve mollusks, and in certain locations helps to stabilize unconsolidated sediments and shorelines. Between the years 2001 and 2010, sections of the coast were flown and photographed using Kodak 2448 and 2427 film at a scale of 1:12000. Areas in the present study, were flown in the months of June though September during the 2001 to 2010 time period. When possible, photography was at the time of extreme low tides, low wind velocity, good water clarity, and maximum biomass of eelgrass. These factors aid in the detection of the subtidal portion a bed. Polygons delineating stands of eelgrass were screen digitized and coded using a four category scale of percent cover. Verification was carried out by boat, on foot, and by plane. Though dense patches of eelgrass approximately 6 meters in diameter and less can be identified under good conditions and in some cases were mapped, a conservative estimate of the minimum mapping unit is 150 square meters. This represents a stand of approximately 14 meters in diameter.

Purpose

Eelgrass beds along the Maine coast have been mapped in order to better understand their importance as habitat, to record the present day distribution, and to aid in the identification of this sensitive coastal habitat for protection in the case of an oil spill.

Status

Maintenance and Update Frequency	As needed

Bounding Coordinates

West Bounding Coordinate	-70.880356
East Bounding Coordinate	-66.966782
North Bounding Coordinate	45.112744
South Bounding Coordinate	43.055169

Keywords

Theme	BIOLOGY, habitat, eelgrass, submerged aquatic vegetation (SAV), coastal, Zostera marina (None)
Theme	biota, environment, oceans (ISO 19115 Topic Categories)

Access Constraints

None

Use Constraints

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 correct copy of both data and metadata from the Maine GIS Data Catalog. Updates, corrections, and feedback, incorporated in the Maine GIS database are made in accordance with "Data Standards for Maine Geographic Information Systems", 2002, and coordinated by MEGIS.

Contact Organization

Maine Department of Marine Resources

Contact Person

Linda Mercer

Contact Position

Bureau Director

Contact Electronic Mail Address

linda.mercer@mane.gov

Browse Graphic File Name

metadata.jpg

Data Set Credit

This data was produced by the Maine Department of Marine Resouces, Bureau of Resource Management. Credit should always be given to the data source and/or originator when the data is transferred or printed.

Native Data Set Environment

Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcGIS 10.0.3.3600

Direct Spatial Reference Method

Vector

SDTS Point and Vector Object Type

GT-polygon composed of chains

Point and Vector Object Count

5179

Map Projection Name

NAD 1983 UTM Zone 19N

Scale Factor at Central Meridian

0.9996

Longitude of Central Meridian

-69.0

Latitude of Projection Origin

0.0

False Easting

500000.0

False Northing

0.0

Planar Coordinate Encoding Method

coordinate pair

Abscissa Resolution

0.00015625

Ordinate Resolution

0.00015625

Planar Distance Units

Meter

Horizontal Datum Name

D North American 1983

Ellipsoid Name

GRS 1980

Semi-major Axis

6378137.0

Denominator of Flattening Ratio

298.257222101

Entity Type Label

Eelgrass2010

Entity Type Definition

polygon attribute table

Entity Type Definition Source

Environmental Systems Research Institute, Inc. (ESRI)

Attribute Label

OBJECTID_1

Attribute Definition

Internal feature number.

Attribute Definition Source

ESRI

Unrepresentable Domain

Sequential unique whole numbers that are automatically generated.

Beginning Date of Attribute Values

Attribute Label

ACRES

Attribute Definition

Area of polygon in acres

Attribute Definition Source

user calculated

Beginning Date of Attribute Values

Attribute Label

COVER

Attribute Definition

Eelgrass percent cover based on crown cover categories as adapted by Orth et al and described in Orth, R.J., J.F. Nowak, D.J. Wilcox, J.R. Whiting, and L.S. Nagey. 1998. Distribution of Submerged Aquatic Vegetation in the Chesapeake Bay and Tributaries and the Coastal Bays –1997. VIMS Special Scientific Report Number 138. 351 pp.

Attribute Definition Source

user defined

Enumerated Domain Value

Enumerated Domain Value Definition

gt 0% to 10% cover

Enumerated Domain Value

Enumerated Domain Value Definition

gt 10% to 40% cover

Enumerated Domain Value

Enumerated Domain Value Definition

gt 40% to 70% cover

Enumerated Domain Value

Enumerated Domain Value Definition

70% to 100% cover

Enumerated Domain Value

Enumerated Domain Value Definition

eelgrass present but % cover not coded

Enumerated Domain Value

Enumerated Domain Value Definition

no eelgrass - dounut

Beginning Date of Attribute Values

Attribute Label

HECTARES

Attribute Definition

Area of polygon in hectares

Attribute Definition Source

user calculated

Beginning Date of Attribute Values

Attribute Label

OBJECTID

Attribute Definition

Recalculated prior to publication. OBJECTID = FID + 1

Attribute Definition Source

ESRI

Unrepresentable Domain

Sequential unique whole numbers that are automatically generated.

Beginning Date of Attribute Values

Attribute Label

YEAR

Attribute Definition

Calendar year that photography was aquired.

Attribute Definition Source

Date of photography

Range Domain Minimum

0.03299

Range Domain Maximum

2497039.87500

Beginning Date of Attribute Values

1992

Ending Date of Attribute Values

2005

Attribute Label

SHAPE

Attribute Definition

Feature geometry.

Attribute Definition Source

ESRI

Unrepresentable Domain

Coordinates defining the features.

Beginning Date of Attribute Values

Attribute Label

location

Attribute Definition

Location vertically along the shore. Intertidal locations are exposed at mean low water. This was applied only from Schoodic Point, east.

Enumerated Domain Value

Enumerated Domain Value Definition

intertidal - exposed at mean low water

Enumerated Domain Value

Enumerated Domain Value Definition

subtidal - below the surface of the water at mean low water

Beginning Date of Attribute Values

Attribute Label

Shape.area

Beginning Date of Attribute Values

Attribute Label

Shape.len

Beginning Date of Attribute Values

Entity and Attribute Overview

eelgrass05 POLYGONS are attributed with percent of eelgrass COVER.

Entity and Attribute Overview

eelgrass05 POLYGONS are attributed with percent of eelgrass COVER.

Metadata Reference Information

Metadata Date	20120703
Metadata Standard Name	FGDC Content Standard for Digital Geospatial Metadata
Metadata Standard Version	FGDC-STD-001-1998
Metadata Time Convention	local time