Resources

Gulf of Maine Library Collection

Identification of Important Habitats in the Lower Casco Bay (Maine) Watershed

GIS COVERAGES PRODUCED DURING THE CASCO BAY HABITAT ANALYSIS

Wetlands: National Wetlands Inventory Data (NWI) were used in this analysis; these data may be obtained directly from NWI

The following digital data are in a band interleaved by line (.bil) raster format and may be imported into GIS and viewer programs. The header information enclosed with each compressed file is correctly read by ARCINFO GRID and most versions of ARCVIEW. An alternative header file (av2.blw) is provided to allow correct positioning of gridcells in some versions of ArcView 2; it may be used to replace the <theme>.blw files for this application.

Three vector coverages are provided (in ARCINFO export format, zipped) to provide background spatial references. These are: lakes, streams, and coast.

Download lakes.zip, streams.zip, coast.zip.

General Attributes of Digital Data (see also cell value explanation by theme, below)

Cell Size = 30.153 Data Type: Integer

Number of Rows = 1787

Number of Columns = 1840 Attribute Data (bytes) = 8

BOUNDARY

Xmin = 385527.547

Xmax = 441009.827

Ymin = 4818621.686

Ymax = 4872505.835

COORDINATE SYSTEM DESCRIPTION

Projection UTM

Zone 19

Units METERS Spheroid CLARKE 1866

Landcover: Grid classified from Landsat image

Name: NEW17 <zipped .bil and headers>

Cell Values:

3 (beach, dune)

4 (inland rock outcrop, ledge)

8 (open water)

9 (submerged aquatic vegetation)

10 (emergent (marsh) vegetation)

11 (forested wetlands)

12 (intertidal flats)

21 (developed)

22 (grass, pasture)

23 (crops, bare earth)

24 (forested uplands)

Bathymetry: Grid from various sources

Name: BATHY <zipped.bil and headers>

Cell Values:

+3 (in meters;equivalent to the elevation of high tide, ref. mlw)

-60 (in meters; greatest depth, ref. mlw)

NOTE: GRIDCELL VALUES FOR THE FOLLOWING BIOLOGICAL THEMES HAVE BEEN INDEXED USING HABITAT QUALITY, RELATIVE SCARCITY, AND THE RANK OF EACH SPECIES ON THE GULF OF MAINE COUNCIL PRIORITY LIST

Cordgrass: Grid from NWI data

Name: CORDGRS4 <zipped.bil and headers>

Cell Values:

0 (not present)

8 (present)

Eelgrass: Grid from Maine DMR

Name: CASEELG6 <zipped.bil and headers>

Cell Values:

0 (not present)

4 (0 - 10% crown cover)

8 (10 - 40% crown cover)

12 (40 - 70% crown cover)

16 (70 - 100% crown cover)

Shellfish: Grid from Maine DMR

Name: SHELL3G <zipped.bil and headers>

Cell Values:

0 (not harvested)

4 (harvested)

Marine Worms: Grid from Maine DMR

Name: WORM4G <zipped.bil and headers>

Cell Values:

0 (not harvested)

8 (harvested)

Common Loon: Grid from model

Name: LOONHAB7 <zipped.bil and headers>

Cell Values:

0 (not suitable)

4 (suitable foraging habitat)

8 (preferred reproductive or foraging habitat)

Black Duck: Grid from model

Name: BDHAB14 <zipped.bil and headers>

Cell Values:

0 (not suitable)

4 (suitable foraging habitat)

4 - 6 (suitable brood-rearing or post-fledging habitat)

8 (preferred reproductive or foraging habitat)

Bald Eagle: Grid from MDIF&W data

Name: EAGBUFG2 <zipped.bil and headers>

Cell Values:

0 (not within Essential Habitat)

64 (Uplands within Essential Habitats)

Roseate Tern: Grid from MDIF&W data and model

Name: ROSEATE6 <zipped.bil and headers>

Cell Values:

0 (not suitable)

8 (suitable depth and in area used by cormorant or terns)

16 (suitable depth and in area used by cormorant and terns)

56 (nesting island)

Seabirds: Grid of foraging and nesting habitats for eiders and terns, and draft NRPA seabird nesting islands

Name: SEABHAB2 <zipped.bil and headers>

Cell Values:

0 (not suitable)

4 (suitable foraging habitat for eiders or terns)

8 (preferred foraging habitat for eiders or terns)

24 (nesting island)

Shorebirds: Grid of nesting and foraging areas.

Name: SHORBG6 <zipped.bil and headers>

Cell Values:

0 (not suitable)

16 (potential nesting habitat for plovers or terns)

16 (known foraging habitats for plovers or terns)

32 (known nesting habitats for plovers or terns)

Wading Birds: Grid of foraging and nesting habitats for wading birds.

Name: WADEHAB2 <zipped.bil and headers>

Cell Values:

0 (not suitable)

4 (suitable foraging habitat)

8 (preferred foraging habitats near to nesting colonies)

32 (nesting habitats)

Freshwater and Anadromous Fishes: Grid of stream and lake habitats.

Name: FISHHAB5 <zipped.bil and headers>

Cell Values:

0 (not suitable)

4 (suitable habitat, some fisheries value)

8 (intermediate fisheries value)

16 (high fisheries value)

Aggregated Habitat Scores: Grid of summed scores for all species.

Name: FINTEST3 <zipped.bil and headers>

Cell Values:

0 (not suitable)

53 (highest scored habitat)

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