OVERVIEW

Living Waters Core Habitats is one of two datalayers resulting from the Living Waters project (see also the NHESP Living Waters Critical Supporting Watershed datalayer description). Core Habitats represent lakes, ponds, rivers, and streams that are important for the protection of freshwater biodiversity in Massachusetts. Natural Heritage and Endangered Species Program biologists delineated Core Habitats for rare aquatic species and exemplary aquatic habitats using Natural Heritage Element Occurrences along with other field data sets. The Core Habitats were “heads-up” digitized (drawn on screen) by the biologists in ArcView 3.2 at a 1:25,000 scale or larger. Areas of overlap among the individual species or community habitat areas were merged together to create the aggregate Core Habitat polygons in this coverage. MassGIS stores this polygon layer in ArcSDE as LWCORE_POLY.

Core Habitats were delineated by Natural Heritage biologists in the ArcView 3.2 environment, using the MassGIS digital topographic quadrangles or 1:5,000 black and white orthophotos as a base map. Where available, GPS data from site visits were used to guide Natural Heritage biologists as they clipped out Core Habitats from the 1:25,000 River Centerlines and the 1:25,000 MassGIS Hydrography. Where the centerlines did not exist or were not available, only the 1:25,000 MassGIS Hydrography was used. In some instances, field sites visited by project scientists were not present in the existing hydrographic data, and so the Core Habitats for these locations were created using onscreen digitizing from the black and white orthophotos.

As each Core Habitat was delineated, it was given a unique identifier, which was entered into an aquatics database along with information about the species or community. After all Core Habitats were delineated, those areas represented as lines (streams and small rivers) were buffered by 10 meters. These were then dissolved into the polygon habitat areas (ponds and large rivers) to create one datalayer of continuous features. Finally, overlapping Core Habitats were aggregated into larger units, called Living Waters Core Habitats, which were attributed with their own unique identifiers and clipped to the state boundary. A total of 429 Living Waters Core Habitats were delineated by Natural Heritage biologists, but this number was reduced to 428 after clipping to the state boundaries.

The LWCORE_POLY polygon attribute table contains the following item:
 

LW_ID

5

5

C

Living Waters Core Habitat ID. This identifier links to the appropriate Critical Supporting Watershed delineated for the Core Habitat.

• The legend that MUST accompany this datalayer on ALL maps is:
"NHESP Living Waters Core Habitats"
• Please note that Core Habitat polygons were designed for use at a regional or town scale. For accurate portrayal, the data should be displayed at scales of less than 1:25,000 (e.g. 1:30,000).
• This datalayer is intended for conservation planning purposes only - it has no regulatory significance. The NHESP layers designed for regulatory use are produced in the Natural Heritage Atlas.

Questions about this datalayer should be directed to NHESP at 508-792-7270 x200.

This layer is one of two Living Waters layers from NHESP. Also see the NHESP Living Waters Critical Supporting Watersheds datalayer description.

• The Living Waters Critical Supporting Watersheds, which are areas with the most immediate hydrologic contributions to Living Waters Core Habitats, and are therefore areas with the highest potential to sustain or degrade them. See this datalayer's metadata for more details.
• The Natural Heritage & Endangered Species Program has published two reports:
• ‘Living Waters: Guiding the Protection of Freshwater Biodiversity in Massachusetts’, a full color report on the Living Waters project
• ‘Living Waters Technical Report’, which provides greater technical detail on the methodology used in the Living Waters project.

Last Updated 12/5/2003
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