Northeast Coastal Areas Study
Significant Coastal Habitats
Site 2 (NY)
I. SITE NAME: Three Harbors Area
II. LOCATION: This major habitat complex of deep glacial bays and harbors and associated uplands, coastal beaches and wetlands is located on the north shore of Long Island along the shoreline of western Long Island Sound. The area is bisected by the Nassau-Suffolk County line.
TOWNS: Huntington, Oyster Bay
COUNTIES: Nassau, Suffolk
STATE: New York
USGS 7.5 MIN QUADS: Huntington, NY 40073-74;
Hicksville, NY 40073-75; Northport, NY 40073-83; Lloyd Harbor,
NY-Conn 40073-84; Bayville, NY-Conn 40073-85
USGS 30x60 MIN QUAD: Long Island, West 40073-E1
III. GENERAL BOUNDARY: The delineated area on the accompanying map extends from Oak Neck Creek and Mill Neck Creek, near Bayville, in the Town of Oyster Bay, Nassau County, east to Northport Bay and Crab Meadow in Huntington, Suffolk County, an east-west linear distance of approximately 14 miles (23 km). The greatest distance for this complex in a north-south direction, or from the coast inland, is approximately 8 miles (13 km). The area includes the adjacent nearshore waters of western Long Island Sound out to a depth of approximately 30 feet (9 meters), and, from west to east, the following protected and semi-enclosed water bodies: Mill Neck Creek, Oyster Bay, Oyster Bay Harbor, Cold Spring Harbor, Lloyd Harbor, Huntington Bay, Northport Bay and several smaller embayments, harbors and tidal creeks. Associated uplands consist of three major "necks" of land jutting prominently into Long Island Sound - Oak Neck, Lloyd Neck and Eatons Neck - and several relatively smaller "necks" within the bays, specifically Mill Neck, Cove Neck, West Neck, East Neck and Little Neck.
IV. OWNERSHIP/PROTECTED STATUS: The area contains two National Wildlife Refuges (Oyster Bay and Target Rock), Sagamore Hill National Historic Park, several State, County and Town parks and beaches (Crab Meadow, Theodore Roosevelt Memorial Park, Caumsett State Park, Planting Fields State Park, etc.) and smaller preserves owned by private conservation organizations such as The Nature Conservancy, National Audubon Society and local Land Trusts. The vast majority of the total area, however, is a combination of Public Trust waters and private lands.
V. GENERAL HABITAT DESCRIPTION: Habitat diversity in this area is relatively high, ranging from rich, dense upland forests and marshy lowlands to open bay and sound waters and sand beaches. Human development is prominent and extensive over much of the terrestrial landscape. The primary areas of significant fish and wildlife habitat are open bay waters, wetlands and undeveloped beaches. The entire complex is drained by the Oyster Bay and Huntington Bay drainage basins. The majority of open waters of the larger bays ranges from 6 to 30 feet (2-9 meters) below mean low water in depth, with maximum depths of 50-70 feet (15-21 meters). Tidal fluctuation is approximately 7 feet (2 meters) in this area. Elevations along the shore range from sea level to 60 feet (18 meters) or more on the bluffs and even higher in the interior of the "necks" and at the heads of the harbors. Although salt marshes, mudflats and sand beaches line sections of shoreline, much of the area is bordered by residential development ranging from large, sparsely-developed estates to densely-populated communities and heavily-used marinas. There are a few important areas of relatively undisturbed salt marshes, dominated by saltmarsh cordgrass (Spartina alterniflora) and saltmeadow cordgrass (S. patens), although total acreage is not very extensive. Narrow, sparsely vegetated sand, gravel and cobble beaches are found on several of the spits, shorelines and small islands in and along the bays. Bottom sediments in Long Island Sound in this nearshore area are predominantly coarse sands and gravels, like the beaches. Red maple (Acer rubrum) swamps are common and relatively well-developed in the area. Upland forests range from rich deciduous slope forests of tulip poplar (Liriodendron tulipifera), red oak (Quercus rubra) and spicebush (Lindera benzoin) to dry morainal woodlands of chestnut oak (Quercus prinus) and mountain laurel (Kalmia latifolia).
VI. SIGNIFICANCE/UNIQUENESS OF AREA: The open waters of the major embayments of Northport Bay, Oyster Bay, Lloyd Harbor and Cold Spring Harbor contain regionally significant concentrations of wintering and migrating waterfowl, particularly species of special emphasis in the region such as greater scaup (Aythya marila), American black duck (Anas rubripes), American wigeon (Anas americana), canvasback (Aythya valisineria), red-breasted merganser (Mergus serrator), mallard (Anas platyrhynchos), Canada goose (Branta canadensis), common goldeneye (Bucephala clangula), bufflehead (Bucephala albeola) and oldsquaw (Clangula hyemalis). From year to year, use of these bays by wintering waterfowl is influenced in part by the extent of ice cover. These bays are also highly productive marine shellfish and finfish areas. Oyster Bay and others in this area are among the most important oyster-producing waters in New York State, if not the region. American oysters (Crassostrea virginica) are generally found in waters greater than 6 feet (2 meters) in depth, and many of these underwater beds are leased for commercial harvest. Hard-shelled clams (Mercenaria mercenaria) are also abundant in this area and are harvested both commercially and recreationally. These bays also serve as important nursery and feeding areas (April - November) for scup (Stenotomus chrysops), bluefish (Pomatomus saltatrix), Atlantic silverside (Menidia menidia), menhaden (Brevoortia tyrannus), winter flounder (Pseudopleuronectes americanus), striped bass (Morone saxatilis) and blackfish (Tautoga onitis). Winter flounder occur throughout the year, spawning during the winter months (January - March), and are one of the most abundant fisheries resources in the bays. In addition to shellfish and finfish, these bays may also be important feeding habitat for juvenile Kemp's ridley sea turtles (Lepidochelys kempii), a U.S. Endangered species, although more data are needed to document the extent of habitat use by this and other sea turtle species, including loggerhead (Caretta caretta). Large numbers of Northern diamondback terrapin (Malaclemys t. terrapin) have been observed in these waters, and nesting is known to occur here.
Important wetlands, especially salt marshes, of this complex include those at Mill Neck Creek, Oak Neck Creek, Lloyd Point and Crab Meadow, the latter being one of the few large areas of undeveloped salt marsh remaining on the north shore of Long Island. These are extremely valuable areas for many wetland associated species of birds, especially as feeding areas for waterfowl, wading birds, gulls, terns and shorebirds. Known or probable breeding birds of special regional emphasis include green-backed heron (Butorides striatus), black-crowned night-heron (Nycticorax nycticorax), snowy egret (Egretta thula), clapper rail (Rallus longirostris), American black duck, and least bittern (Ixobrychus exilis). Wintering bald eagles (Haliaeetus leucocephalus), a U.S. Endangered species, have also been reported using these areas in recent years. Ospreys (Pandion haliaetus) nest and feed in these areas.
Several undeveloped sand and pebble beaches in the eastern portion of this complex are important nesting areas for piping plover (Charadrius melodus), a U.S. Threatened species, common tern (Sterno hirundo) and least tern (S. antillarum), including one of the largest colonies in New York State of the latter. The more significant areas are beaches at Target Rock, Lloyd Point, Eatons Neck Point and Sand City (West Beach). Population levels vary from year to year based on a number of factors, foremost of which is human-related disturbance during the critical nesting period (mid-April to August).
VII. THREATS: The area's fish and wildlife populations are under considerable pressure from shoreline and upland development and recreation. The value of open water and benthic (bottom) bay and sound habitats to waterfowl, finfish and shellfish is threatened by contaminants, oil spills, suburban runoff, excessive sedimentation, sewage and stormwater discharges, waste disposal, dredging activities and construction of shoreline structures. These waters are subject to low oxygen levels (hypoxia) during the summer months which, when prolonged, can stress and even kill marine organisms. Wetland habitats are additionally threatened by ditching, draining and filling activities not specifically designed or intended to enhance the fish and wildlife values of these habitats. Piping plovers and terns are extremely vulnerable to human disturbance, both from off-road vehicles and pedestrians, during the nesting season, which can lead to seasonal or even permanent abandonment of the beach sites. Predators, especially dogs, cats and rats, can be destructive to the beach nesting colony and are clearly a major problem in some, if not most, areas. Nesting beaches as well as adjacent marsh and tidal flat feeding areas are potentially threatened by unregulated dumping of dredge spoils or by shoreline structures that might accelerate beach erosion.
VIII. CONSERVATION CONSIDERATIONS: With regard to open water and benthic habitats in the large bays and nearshore environments of Long Island Sound, specifically as it applies to the conservation of waterfowl, marine turtles, finfish and shellfish dependent upon these areas, appropriate protective measures should be taken. Regulation, zoning, planning or cooperative management agreements should be pursued to ensure the achievement and maintenance of a high level of water quality and to protect such areas from the hazards of chemical and sewage pollution and sediment discharges. Harvests of all commercially and recreationally exploited species need to be closely monitored to ensure that optimum sustainable populations are maintained over the area. Disturbances to wintering concentrations of waterfowl in these areas from whatever source should be minimized. Beach habitats of nesting piping plovers and terns 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, warden patrols and public education. Applicable objectives and tasks of the piping plover recovery plan should be implemented, wherever possible. Protection of specific tracts or sites, particularly those significant sites identified on the accompanying map, can be accomplished by a variety of mechanisms ranging from easements and cooperative agreements, zoning and land-use regulations, planning, tax incentives, mutual covenants and land exchanges to acquisition. The Three Harbors Complex offers an abundance of creative land and resource conservation opportunities and challenges involving the cooperative efforts of Federal, State, County and local governments in partnership with private conservation organizations such as The Nature Conservancy, National Audubon Society and various local Land Trusts, and, most importantly, private landowners.
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