Northeast Coastal Areas Study
Significant Coastal Habitats

Site 36 (MA)


I. SITE NAME: Nantucket Sound Barrier Beach\Bay Complex

II. LOCATION: Three separate areas located along the Nantucket Sound shoreline of Cape Cod, Massachusetts, from East Falmouth to South Yarmouth.

TOWNS: Barnstable, Dennis, Falmouth, Mashpee, Yarmouth
COUNTY: Barnstable
STATE: Massachusetts
USGS 7.5 MIN QUADS: Cotuit, Mass 41070-54; Falmouth, Mass 41070-55; Dennis, Mass 41070-62
USGS 30x60 MIN QUAD: New Bedford 41070-E1

III. GENERAL BOUNDARY: This complex includes the three major barrier beach-bay systems and nearshore waters of 1) Waquoit Bay, just east of East Falmouth; 2) Cotuit Bay, between the communities of Cotuit and Osterville; and 3) Bass River in South Yarmouth. The boundaries of each of these sites is delineated on the accompanying maps. Although these individual areas are not joined by a common boundary as with other complexes in this study, there are significant ecological and physiographical similarities among these systems to warrant their management consideration as a single complex.

Within each beach-bay system several individual sites of fish and wildlife significance are recognized, and are delineated on the map for each system. The Bass River system includes Bass River, Davis Beach, Stage Island Harbor and Lewis Pond. The Waquoit Bay system includes South Cape Beach and Dead Neck, Washburn Island, Great Pond, Eel Pond, Waquoit Bay, Sage Lot Pond, Hamblin Pond and Jehu Pond. The Cotuit Bay system includes Cotuit Bay, Seapuit River, North Bay, Oyster Harbors Beach, Sampsons Island and Popponesset Beach.

IV. OWNERSHIP/PROTECTED STATUS: Public Trust waters, Waquoit Bay National Estuarine Research Reserve (State DEM/NOAA), several State and Town parks and beaches, and extensive private lands and beaches.

V. GENERAL HABITAT DESCRIPTION: The barrier beach-bay systems of this complex are generally made up of the following physiographic units: nearshore waters and sediments; barrier beach, including beach, dunes and sand flats; estuaries and bays; tidal wetlands, including salt and brackish marshes; brackish or salt ponds; embayed islands; rivers and streams; freshwater wetlands; and upland areas. Beaches in this area are generally sandy, gravelly or cobbly shores. Associated dunes are made up of highly quartzose sands dominated by American beachgrass (Ammophila breviligulata) and seaside goldenrod (Solidago sempervirens) and by beach plum (Prunus maritima) and bayberry (Myrica pensylvanica) on the backside of the dunes. Salt and brackish marshes are generally dominated by cordgrasses (Spartina alterniflora and S. patens), often in mixed associations with spike grass (Distichlis spicata) and black grass (Juncus gerardii), and with an upland shrub border of marsh elder (Iva frutescens) and groundsel-bush (Baccharis halimifolia). Upland forests are typically mixed hardwoods of several species of oaks (Quercus spp.) and pitch pine (Pinus rigida) with sassafras (Sassafras albidum), black cherry (Prunus serotina) and other species. Freshwater wetlands are diverse and include cattails (Typha angustifolia and T. latifolia), swamp azalea (Rhododendron viscosum), and several species of sedges (Carex spp.) and rushes (Juncus spp.). The estuaries and bays often have extensive beds of eelgrass (Zostera marina) and macroalgae, especially sea lettuce (Ulva lactuca). Residential development surrounds much of these areas.

VI. SIGNIFICANCE/UNIQUENESS OF AREA: The sand beaches along the barrier islands in each of the systems identified here are regionally important nesting areas for colonial beach-nesting birds, especially for piping plover (Charadrius melodus), a U.S. Threatened species, roseate tern (Sterna dougallii), a U.S. Endangered species, least tern (S. antillarum) and common tern (S. hirundo). The enclosed bay waters are important wintering waterfowl concentration areas, and species of special emphasis which commonly overwinter here include American black duck (Anas rubripes), Atlantic brant (Branta bernicla), greater and lesser scaup (Aythya marila, A. affinis), Canada goose (Branta canadensis), common goldeneye (Bucephala clangula), bufflehead (Bucephala albeola) and common loon (Gavia immer). Scoters (Melanitta spp.), oldsquaw (Clangula hyemalis) and common eider (Somateria mollissima) often winter in nearby offshore waters in large concentrations. Breeding birds of the tidal and freshwater marshes in these systems include: green-backed heron (Butorides striatus), snowy egret (Egretta thula), American black duck, mallard (Anas platyrhynchos) and osprey (Pandion haliaetus). The bay waters are especially important as spawning and nursery areas for winter flounder (Pseudopleuronectes americanus), menhaden (Brevoortia tyrannus) and tautog (Tautoga onitis), and have significant resident populations of silverside (Menidia menidia) and killifish (Fundulus spp.). Anadromous fish also migrate through these bays to spawn upstream in the rivers and streams that feed into the bays, and include alewife (Alosa pseudoharengus), rainbow smelt (Osmerus mordax), blueback herring (Alosa aestivalis) and striped bass (Morone saxatilis). There are important shellfish beds in these areas, especially of hard-shelled and soft-shelled clams (Mercenaria mercenaria and Mya arenaria, respectively). Northern diamondback terrapins (Malaclemys t. terrapin) nest and feed in these areas. Rare plants occurring in this vicinity include sandplain gerardia (Agalinis acuta), as U.S. Endangered species, bushy rockrose (Helianthemum dumosum) and several species of State concern.

VII. THREATS: The primary threat to this area and its valuable estuarine waters and coastal lands is increasing development of the shoreline and heavy residential densities in the watersheds of these bay systems, with consequent threats to water quality and the continued suitability of these areas for regionally significant fish and wildlife populations. Several of the communities in the area contain no public sewers. The sandy soils and low water table of the Cape provide little buffer to effectively treat the types of pollution normally associated with dense residential development. Other pollution threats include rubbish, oil, non-consumed fuel and sewage release associated with boat use; stormwater runoff and discharges; and pesticides and nutrients associated with cranberry bog farming. Beach habitats of nesting piping plovers and terns are highly vulnerable to a variety of human-related disturbances, from both pedestrians and beach vehicles, and also from loose pets as well as other human-associated species. Disturbances during the critical nesting season (mid-April to August) can lead to seasonal or even permanent abandonment of the site.

VIII. CONSERVATION CONSIDERATIONS: One of the most important resource issues facing these bay systems on Cape Cod is the protection, and in many cases improvement, of water quality in the bays, rivers and nearshore waters of these areas. Appropriate measures need to be taken, including regulation and enforcement, zoning, planning and cooperative management agreements, to ensure the achievement and maintenance of a high level of water quality and the continued long-term value of these areas for fish and wildlife resident populations and seasonal concentrations of regional importance. Human related disturbances to beach-nesting terns and piping plovers is also of major concern and should be prevented during the nesting season by utilizing all available means, including protective fencing and exclosures, posting, beach warden patrols, predator/pet removal and public education. Efforts should be sought to identify and implement pertinent tasks and objectives of the piping plover and roseate tern recovery plans that might be applicable to beaches within this complex, including those involving habitat restoration or enhancement.


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