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Anadromous fish index

The anadromous fish index identifies large and medium rivers that provide habitat for five anadromous fish species: American shad, blueback herring, shortnose sturgeon, alewife, and sea lamprey. The layer is based on The Nature Conservancy’s Connecticut River Basin Program spatial data product of diadromous fish habitat. That layer was created in 2010 and updated by Renee Farnsworth of the North Atlantic LCC. River segments accessible by more species received a higher score. All river segments accessed by at least one species are included in the lotic cores. Also, all segments were labeled “free-flowing,” “impounded,” or “unknown.”

Habitat includes the mainstem and major tributaries of the Connecticut River from the mouth of the river upstream to the limit of passability for these species. This product should not be used to assess habitat suitability for aquatic species since it does not account for habitat characteristics such as flow, water temperature, gradient or substrate.

View this product as a web map on Data Basin.

Access this data as a GIS download from the North Atlantic LCC website.

Read the Technical Abstract for this data layer (anadromous.shp).

Photo Credit: Alewives in Connecticut, by NOAA