This shellfish habitat layer was derived from datasets from Maine, Massachusetts and New Hampshire state GIS resources. Shapefiles downloaded/provided from these states include delineated shellfish habitats for oysters (American oyster, Eastern oyster, European oyster), clams (Atlantic surf clam, ocean quahog, quahog, razor clam, and soft-shell clam), blue mussel, and scallops (bay scallop and sea scallop). Maine’s molluscan shellfish layer is based on habitat distribution data from February 2008 to September 2010 provided by town officials, harvesters, harbormasters, Maine Department of Marine Resources (MEDMR) biologists, MEDMR specialists, MEDMR Marine Patrol officers and MEDMR scientists. The Massachusetts shellfish suitability data maps areas along the coast of Massachusetts where shellfish have been observed since the mid-1970’s depicting areas that are suitable for shellfish habitats. This data is a compilation of information provided by Massachusetts Division of Marine Fisheries, local shellfish constables, commercial fisherman, maps and studies. The New Hampshire dataset contains delineations of tidal shellfish beds from 2005 to 2013 provided by data from New Hampshire Department of Environmental Services (NHDES) Shellfish Program, Morrissey, E and C. Nash (2013), University of New Hampshire [Grizzle, R. and K. Ward (2009 and 2013), Capone et al. (2008)], and Normandeau Associates, Inc. (2008). This regional dataset does not include shellfish habitats for Connecticut, New York or Rhode Island; however, this dataset will be updated to include these states once data is available.This dataset shows shellfish suitability areas (habitats) for eleven shellfish species (Atlantic surf clam, ocean quahog, quahog, razor clam, soft-shell clam, blue mussel, American oyster, Eastern Oyster, European oyster, bay scallop, and the sea scallop) for New Hampshire, Maine, and Massachusetts.