Northeast Coastal Areas Study
Significant Coastal Habitats
Site 34 (MA)
I. SITE NAME: Buzzards Bay Colonial Bird Nesting and Feeding Areas
II. SITE LOCATION: Bird Island and Ram Island are located just offshore the western shoreline of Buzzards Bay, northeast of the city of New Bedford, in the vicinity of the Towns of Marion and Antassawamock, respectively.
TOWNS: Mattapoisett, Marion
USGS 7.5 MIN QUADS: Naushon Island, Mass 41070-47; Woods Hole, Mass 41070-56; Sconticut Neck, Mass 41070-57; Onset, Mass 41070-66; Marion, Mass 41070-67
USGS 30x60 MIN QUADS: Martha's Vineyard 41070-A1; New Bedford 41070-E1
III. GENERAL BOUNDARY: There are two distinct, separate and yet closely related areas comprising this complex: 1) an area on the western and upper portions of Buzzards Bay enclosing two small offshore islands (Ram Island and Bird Island) and a large group feeding area; and 2) a nearshore area of open waters along the lower, eastern shoreline of Buzzards Bay important as a general feeding area for individual birds. Ram Island forms the southwestern boundary of the first area and is situated about 0.5 miles (1 km) south of Antassawamock in the Town of Mattapoisett. Moving northeastward from Ram Island the boundary encloses Bird Island, located about 0.5 miles (1 km) south of Sippican Neck in the Town of Marion, to Great Neck and up into Buttermilk Bay at the head of Buzzards Bay. The dimensions for this area are approximately 10 miles (16 km) long in a southwest-northeast direction and about 3 miles (5 km) wide in a northwest-southeast direction along the western shoreline of Buzzards Bay. The second area is located approximately 10 miles (16 km) south of Bird Island and consists entirely of the nearshore waters around Woods Hole and the northern half of Naushon Island out to about 0.5 miles (1 km) from the shoreline. This second area is approximately 6 miles (10 km) long in a southwest-northeast direction and 2 miles (3 km) wide in a northwest-southeast direction. The general boundaries for both areas are delineated on the accompanying maps.
IV. OWNERSHIP/PROTECTED STATUS: These areas consist entirely of public lands and waters. Ram Island is owned by the State of Massachusetts, Division of Fisheries and Wildlife; Bird Island is owned by the Town of Marion and managed by the Massachusetts Audubon Society.
V. GENERAL HABITAT DESCRIPTION: Both islands are approximately an acre (0.5 ha) in size and are located about a half mile (1 km) from the western mainland shoreline of Buzzards Bay. Bird Island is rocky and densely covered with herbaceous plants including beach grass (Ammophila breviligulata), bindweed (Convolvulus sepium), seaside goldenrod (Solidago sempervirens), black mustard (Brassica nigra), seaside angelica (Coelopleurum lucidum) and lamb's quarters (Chenopodium album). Ram Island is a low island composed of sand, gravel and larger stones with elevations in the center high enough to support vegetation such as beachgrass and seaside goldenrod. Feeding areas used by individual birds are generally over shoals and submerged sandbars and tidal rips, while waters favored by large feeding flocks are cool, deep and clear where schools of small fish are driven to the surface by predatory fish such as bluefish (Pomatomus saltatrix) and striped bass (Morone saxatilis).
VI. SIGNIFICANCE/UNIQUENESS OF AREA: The Bird Island population of roseate terns (Sterna dougallii), a U.S. Endangered species, is the single largest breeding colony of this species in North America, roughly 1500 nesting pairs, comprising approximately half the known breeding population. Since the 1920's, there has been a severe reduction in most major roseate tern nesting sites, largely due to abandonment subsequent to occupation of the colonies by herring gulls (Larus argentatus) and great black-backed gulls (Larus marinus). An estimated 2500 pairs of roseates nested on Ram Island in 1947, but by the early 1960's this colony was largely overrun by gulls. Currently, no roseate terns nest on Ram Island, although this island is targeted for restoration. Common terns (Sterna hirundo) also nest in significant numbers on Bird Island, approximately 800 pairs. The tern feeding areas are rich in American sandlance (Ammodytes americanus), sea herring (Clupea harengus), blue-backed herring (Alosa aestivalis) and round herring (Etremeus teres), preferred forage fish for terns in this area. Towards the northeastern end of this complex, near the head of Buzzards Bay, piping plovers (Charadrius melodus), a U.S. Threatened species, currently nest on sand beaches near Stony Point on Great Neck, and in the recent past nested on Long Beach Point to the west, at the mouth of the Wareham River. Piping plovers also nest a few miles southwest of Ram Island, on the east end of West Island. The western and upper Bay waters of this complex are important wintering areas for Atlantic brant (Branta bernicla), American black duck (Anas rubripes), greater scaup (Aythya marila) and common goldeneye (Bucephala clangula), while the waters around Woods Hole hold significant wintering concentrations of common eider (Somateria mollissima) and oldsquaw (Clangula hyemalis).
VII. THREATS: Within the study region of southern New England and New York, and generally throughout the Northeast, the reduction of breeding colonies of roseate terns (and other species of terns) has been attributed to displacement by herring gulls and great black-backed gulls, a problem which continues today. Although most site abandonment has been closely associated with gull predation on tern eggs and chicks, in some instances it may have been due to displacement of terns to less favorable sites closer to the shore rendering them more susceptible to predation from mainland-based predators. In addition to gulls, other significant predators on roseate terns include brown rat (Rattus norvegicus), great horned owl (Bubo virginianus) and black-crowned night-heron (Nycticorax nycticorax). Chemical contaminants, including PCBs and organochlorines, are of major concern in certain parts of Buzzards Bay, particularly around New Bedford Harbor.
VIII. CONSERVATION CONSIDERATIONS: Recovery efforts for roseate terns in the Northeast region require aggressive gull removal programs at sites formerly occupied by nesting roseates and subsequently displaced by herring gulls and great black-backed gulls. Ram Island has already been targeted for gull removal operations using Gull Toxicant 1339 in a joint State-Federal program and, if successful, could result in the recolonization of this island by roseate terns from Bird Island and other colonies. Beach habitats of nesting terns and piping plovers are highly vulnerable to a variety of human-related disturbances and stringent protective measures are necessary throughout the critical nesting and young-rearing seasons, including protective fencing, beach closures, predator removal and warden patrols. Efforts should be made to identify and implement pertinent tasks and objectives of the roseate tern and piping plover recovery plans that might apply to the Buzzards Bay area, particularly opportunities to restore and enhance habitat. Consideration should be given to adding dredging spoil deposits on and around Bird Island during the non-nesting season to expand its size and increase the availability of nesting sites for roseate terns. Contact should be made with the Army Corps of Engineers to discuss the feasibility of doing this. Monitoring of both Bay waters and living organisms, particularly roseate terns, for chemical contaminants needs to be given high priority, including measures to clean-up and restore these areas. Attention should be given during any clean-up activities in the New Bedford Harbor area to ensure that contaminants resuspended or released into the water column will not be a problem for terns on either Ram or Bird Islands.
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