Northeast Coastal Areas Study
Significant Coastal Habitats

Site 1 (CT, NY)


I. SITE NAME: The Narrows Complex

II. LOCATION: The Narrows constitutes the westernmost section of Long Island Sound between Hell Gate, at the convergence of the Harlem and East Rivers, and the Hempstead Sill, a major shoal area extending north and south across the Sound from Matinicock Point on Long Island, near Glen Cove, Nassau County, to the New York-Connecticut boundary. This complex also includes a small area of southwestern coastal Connecticut in the vicinity of Greenwich.

TOWNS: New Rochelle, Mamaroneck, Queens, North Hempstead (NY); Greenwich (CT)
COUNTIES: Nassau, Queens, Westchester (NY); Fairfield (CT)
STATES: New York, Connecticut
USGS 7.5 MIN QUADS: Sea Cliff, NY 40073-76; Flushing, NY 40073-77; Mamaroneck, NY 40073-86; Mount Vernon, NY 40073-87; Bayville, NY-Conn 40073-85; Stamford, Conn-NY 41073-15
USGS 30x60 MIN QUADS: Long Island, West 40073-E1; Bridgeport 41073-A1

III. GENERAL BOUNDARY: The primary boundary of this complex corresponds approximately with that of The Narrows proper, and includes most of the nearshore waters and islands of western Long Island Sound and portions of the East River within this area. Specifically included and delineated on the accompanying map are the three major bays on the north shore of western Long Island, in Nassau and Queens Counties: Little Neck Bay, Manhasset Bay and Hempstead Harbor, which are recognized here as an interrelated complex of regionally significant fish and wildlife aquatic habitats. Although the overall boundary of this complex is considerably more extensive than the individual significant habitat areas identified in the East River section and the Westchester/Bronx and Connecticut shorelines of The Narrows, these habitats were felt to be linked, or potentially so, and thus were included together.

Two major subcomplexes may be recognized in this complex, joined together by the waters of the Sound and ecologically linked with one another: 1) the Northern Bays, comprised of Little Neck and Manhasset Bays and Hempstead Harbor and the immediate nearshore waters of Long Island Sound; and 2) the Mainland Coastline, with its several small offshore islands, mainland wetlands and nearshore waters, bays and coves. The core area of the latter subcomplex essentially extends from Eastchester Bay and the Throgs Neck Bridge in New York eastward to Greenwich Cove in Greenwich, Connecticut. Included within this complex are the following significant fish and wildlife habitat sites: Greenwich Cove, Cos Cob Harbor, and Great Captain Island in Connecticut, and Playland Lake and Manursing Island Flats; Marshlands Conservancy at Maries Neck/Milton Harbor; Premium River - Pine Brook Wetlands; Huckleberry Island - Davids Island; and Pelham Bay Park in New York. Also included in this subcomplex are South and North Brother Islands, just west of Rikers Island near the western boundary of The Narrows, approximately 6 linear miles (10 km) west of the core area. Although these areas may appear disjunct and remote from each other, it is not unreasonable to hypothesize a linkage between the wading colonial bird rookeries on North and South Brother Islands and island rookeries of The Narrows and western Long Island Sound in Connecticut, as being part of a larger metapopulation.

IV. OWNERSHIP/PROTECTED STATUS: As might be expected in one of the most heavily urbanized and industrial parts of the country, most of the area within this complex, except for the waters, is privately-owned. Other than the three North Shore bays, the specific sites identified in the Westchester/Bronx and Connecticut Coastline subcomplex are a mixture of private and public (Federal, County and Town) lands.

V. GENERAL HABITAT DESCRIPTION: The Northern Bays subcomplex is almost exclusively an aquatic habitat complex, with only a few small sections of land identified within the boundary. The reasons for this are, for one, the densely urbanized or disturbed shoreline area along most of the shorelines of the bays, and two, and most importantly, because of the high fish and wildlife values of the bay waters themselves relative to the surrounding lands. The bays are relatively shallow (8-33 feet/2-10 meters) glacial valleys modified by marine processes and strongly interlinked with sediment and water processes in Long Island Sound. Separated from each other by prominent "necks" of land (Great Neck and Manhasset Neck) protruding into Long Island Sound, each of these bays has its own watershed, from which it receives both surface runoff and groundwater discharged from the surrounding land. Because of their restricted water circulation, the sediments in these bays are mostly muds, except near their entrances where sandy deposits predominate. Mean tidal range is approximately 7.2 feet (2.2 meters) and salinity around 25 parts per thousand. Hempstead Harbor is bordered by steep bluffs and headlands, with extensive industrial and commercial development along the shore, while the other two bays are even more developed and have less steep topography along their shores. There are a few wetlands and narrow sand beaches of wildlife significance in this subcomplex, near the mouth of Manhasset Bay, with typical saltmarsh and beach vegetation.

The principal habitat types of significance in the Mainland Coastline subcomplex are: 1) offshore islands with colonial wading bird rookeries; 2) rocky intertidal areas; and 3) tidal wetland areas consisting of various combinations of associated salt and brackish marshes, mudflats, tidal creeks and protected open-water coves. The most important bird-breeding islands in this group are Huckleberry Island, Great Captain Island, North and South Brother Islands, and Pelican Island. These small, rocky islands are mostly covered with deciduous forest composed of sassafras (Sassafras albidum), white oak (Quercus alba), Norway maple (Acer platanoides), chestnut oak (Q. prinus), black locust (Robinia pseudo-acacia) and Tree-of-Heaven (Ailanthus altissima). There are virtually no shrubs under the forest canopy. Poison ivy (Toxicodendron radicans) is locally abundant. Buildings, both abandoned and seasonally occupied, occur on some of the islands. The rocky intertidal shoreline of these islands, as well as areas along the mainland shoreline, are rich in marine species and largely covered with attached algae (Fucus vesiculosus, Ascophyllum nodosum, etc.) and other organisms (shellfish, seastars, barnacles, etc.). The wetlands systems in this area, particularly those of the more significant sites in this subcomplex, are diverse and relatively undeveloped, with tidal rivers and creeks, salt marshes, mud flats, freshwater marshes and shallow water areas occurring over the general area. Salt marshes are dominated by cordgrasses (Spartina alterniflora and S. patens) and other typical marsh species.

VI. SIGNIFICANCE/UNIQUENESS OF AREA: The three North Shore bays are collectively among the most important waterfowl wintering concentration areas in the western portion of the study region, particularly for scaup (Aythya marila, A. affinis), canvasback (Aythya valisineria) and American black duck (Anas rubripes), along with lesser numbers of Atlantic brant (Branta bernicla), Canada goose (Branta canadensis), common goldeneye (Bucephala clangula), oldsquaw (Clangula hyemalis), bufflehead (Bucephala albeola), red-breasted merganser (Mergus serrator) and American wigeon (Anas americana). These bays are also productive nursery and feeding areas for marine shellfish and finfish, including striped bass (Morone saxatilis), scup (Stenotomus chrysops), bluefish (Pomatomus saltatrix), Atlantic silverside (Menidia menidia), menhaden (Brevoortia tyrannus), winter flounder (Pseudopleuronectes americanus) and blackfish (Tautoga onitis), and contain important hard-shelled clam (Mercenaria mercenaria) beds. Although few in number and small in size, sand beaches in this area provide essential nesting habitat for piping plover (Charadrius melodus), a U.S. Threatened species, and least tern (Sterna antillarum), as well as for Northern diamondback terrapin (Malaclemys t. terrapin). Sea-beach knotweed (Polygonum glaucum) was historically reported from beaches in this area and may still be present. Marshlands associated with the bays are valuable feeding and nesting areas for green-backed heron (Butorides striatus), clapper rail (Rallus longirostris), American black duck, and feeding areas for several species of wading birds.

The rocky offshore islands along the mainland shoreline of Bronx, Westchester, and Fairfield Counties support colonial waterbird colonies of regional significance. Huckleberry Island is the largest rookery in western Long Island Sound, with over 460 pairs of double-crested cormorants (Phalacrocorax auritus), 100+ pairs of great egrets (Casmerodius albus), 100+ pairs of snowy egrets (Egretta thula), 300 pairs of black-crowned night-heron (Nycticorax nycticorax), and a pair of glossy ibis (Plegadis falcinellus). Also nesting here, and of considerable management concern, are over 2,000 pairs of herring gulls (Larus argentatus) and 65 pairs of great black-backed gulls (L. marinus) (1989 estimates). Although not nearly as large as the Huckleberry Island rookery, the bird colonies on North and South Brother Islands, especially the latter, are impressive and apparently still expanding. Davids Island, next to Huckleberry Island, does not presently contain any nesting bird colonies, but could potentially provide habitat for expanding or displaced populations of colonial waterbirds nesting on other islands in this complex.

The wetlands along the mainland in this subcomplex provide important nesting habitat for several species of special emphasis in the region, including green-backed heron, yellow-crowned night-heron (Nyctanassa violacea), American bittern (Botaurus lentiginosus), Canada goose, American black duck, and clapper rail. One of these sites - the Marshlands Conservancy - is the only mainland breeding site for yellow-crowned night-herons in this general area and should be viewed as regionally significant. These marshes are used extensively by migrating waterfowl, shorebirds and raptors, and several of the coves and protected embayments along the shoreline and adjacent marshes support moderately-sized wintering populations of American black duck, mallard, scaup, bufflehead and common goldeneye. Concentrations of hard-shelled clams and soft-shelled clams (Mya arenaria) are locally important.

VII. THREATS: Industrial, commercial and residential development in the extremely urbanized environment of The Narrows continues to encroach upon and impact existing natural ecosystems and fish and wildlife populations. In spite of this, many important and regionally significant areas still persist, although their future appears uncertain without intensive and coordinated protection and management programs and environmental safeguards in place. Heavy metal and PCB contamination, oil pollution, sewage and stormwater discharges, waste disposal, shoreline marina development, dredging and numerous other activities that degrade water quality or alter terrestrial and aquatic habitats can and do have devastating impacts on the fish and wildlife resources of this area. The waters of The Narrows and bays are subject to low oxygen levels (hypoxia) during certain times of the year (summer) which, when prolonged, can stress and even kill marine organisms. These hypoxic events are believed to be due to sewage effluent discharged in the waters, resulting in algal blooms and subsequent oxygen depletion. Human disturbances in the form of intrusions into bird nesting areas can cause colonies to be temporarily or even permanently abandoned, and the year's production of young lost through trampling or scattering of nesting birds.

VIII. CONSERVATION CONSIDERATIONS: Protective measures should be taken, whether by regulation, zoning, planning, cooperative agreements or full-scale restoration programs such as the National Estuary Program, to restore, maintain, enhance and protect the aquatic, terrestrial, insular and benthic habitats of The Narrows, the major bays, and the lesser embayments and coves along the mainland to ensure that these areas continue to support the regionally significant populations of waterfowl, fish, and colonial breeding birds that utilize and depend upon these habitats. Programs such as the Long Island Sound Study should continue to address the problems of hypoxia in western Long Island Sound and The Narrows. 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 waterfowl and colonies of nesting waterbirds should be minimized or prevented altogether, particularly with regards to colonial wading birds. Human intrusions into beach nesting areas or island rookeries of wading birds should be prevented or avoided throughout the critical nesting and young-rearing season, utilizing all available means to accomplish this, including fencing, beach closures, posting, warden patrols and public education. Removal of predators from nesting areas may be necessary, whether pets, feral animals or other problem species whose populations have expanded as a result of man's influence. Applicable objectives and tasks of the piping plover recovery plan should be implemented wherever possible. In addition, the development and implementation of a colonial wading bird conservation and management plan that would incorporate the rookeries of The Narrows Complex for western Long Island Sound should be explored.

While many of the aquatic sites and mainland marshes are publicly owned and primarily in need of resource management rather than acquisition, a few of the significant sites are privately owned and under threat of development, especially Davids Island, and could provide opportunities for the development and implementation of various land protection mechanisms, including cooperative conservation and management agreements, zoning and land-use regulations, easements, land exchanges and, in some cases, acquisition. Opportunities should be sought to develop cooperative management and conservation programs between the various governmental agencies, private conservation organizations such as The Nature Conservancy and the National Audubon Society, and the private citizens and landowners of this area to best manage and protect for the long term the wealth of living resources still living, feeding and breeding in this important regional complex.


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