Northeast Coastal Areas Study
Significant Coastal Habitats

Site 3 (NY)


I. SITE NAME: Nissequogue River

II. LOCATION: The river arises in central Long Island from the north slope of the Ronkonkoma Moraine, just west of Hauppauge, flowing northward and northwestward until finally entering Long Island Sound (Smithtown Bay) on the north shore of Long Island.

TOWN: Smithtown
COUNTY: Suffolk
STATE: New York
USGS 7.5 MIN QUADS: Central Islip, NY 40073-72; Saint James, NY 40073-82
USGS 30x60 MIN QUAD: Long Island, West 40073-E1

III. GENERAL BOUNDARY: Although the total river length of the Nissequogue River, from its headwaters to its confluence with Smithtown Bay, is 8.3 miles (13 km), the area of significant fish and wildlife usage is an approximately 7.6 mile (12 km) stretch from Mill Pond dam to the river mouth. This boundary is delineated on the accompanying map.

IV. OWNERSHIP/PROTECTED STATUS: Nearly half of the river corridor is made up of State, County and local parks and private conservation organization nature preserves, and most of the tidal and freshwater wetlands are publicly owned for conservation purposes. The rest of the area is privately-owned in small parcels of residential development.

V. GENERAL HABITAT DESCRIPTION: The river flows in a northerly direction through a number of terrestrial and aquatic ecosystems including freshwater springs, dunes, tidal and freshwater wetlands, and upland and lowland hardwood forests. The topography of the river area is varied except in the vicinity of several large freshwater ponds in the upper sections of the river and in the tidal flats in the lower reaches of the river. The watershed is approximately 29 square miles (7,517 ha). The river drops from its highest elevation of about 29 feet (9 m) above sea level to sea level at Long Island Sound, while elevations within the river corridor range from sea level to 150 feet (46 m) above sea level, with the most rugged terrain occurring in the northernmost third of the river corridor. The river itself provides habitat for a wide variety of aquatic life in freshwater ponds, slow and moderately flowing sections of the river's tributaries, wetlands, brackish and tidal saline river waters.

There are three types of forest within the river corridor: 1) bottomland hardwoods of red maple (Acer rubrum), grey birch (Betula populifolia), tulip tree (Liriodendron tulipifera), black tupelo (Nyssa sylvatica) and beech (Fagus grandifolia); 2) pine barrens, dominated by pitch pine (Pinus rigida), scarlet oak (Quercus coccinea) and bear, or scrub, oak (Q. ilicifolia); and 3) dry oak forests of red (Q. rubra), black (Q. velutina), white (Q. alba), and scarlet oaks, with hickories (Carya spp.). Other plant communities include white cedar (Thuja occidentalis) swamp, freshwater tidal marsh, bogs and various other wetland types. At the mouth of the river are undeveloped barrier beaches and extensive salt marshes and tidal mud flats. Dredging spoil deposits occur on sections of these beaches.

VI. SIGNIFICANCE/UNIQUENESS OF AREA: The Nissequogue River is one of the four major rivers on Long Island, and is important to a great diversity of fish and wildlife species throughout the year. The river provides essential nesting habitat for several species of special emphasis in the region, including Canada goose (Branta canadensis), American black duck (Anas rubripes), clapper rail (Rallus longirostris), osprey (Pandion haliaetus) and several species of passerines and wading birds. It is also important as a waterfowl wintering area, particularly for American black duck, greater and lesser scaup (Aythya marila and A. affinis), red-breasted merganser (Mergus serrator), mallard (Anas platyrhynchos), and Canada goose. Mute swan (Cygnus olor), a problem species throughout the region, also occurs here in moderately large numbers. At least 12 species of warblers breed in the red maple swamps in the river corridor. An Atlantic white cedar swamp occurring here, rare in western Long Island, is habitat for Hessel's hairstreak (Mitouri hesseli), a regionally rare butterfly.

The river is a productive area for finfish and shellfish, especially as a nursery or feeding area for menhaden (Brevoortia tyrannus), bluefish (Pomatomus saltatrix), striped bass (Morone saxatilis), scup (Stenotomus chrysops), winter flounder (Pseudopleuronectes americanus) and blackfish (Tautoga onitis), and there are abundant beds of hard-shelled clam (Mercenaria mercenaria), soft-shelled clams (Mya arenaria) and American oyster (Crassostrea virginica). Northern diamondback terrapin (Malaclemys t. terrapin) nest in the sandy shores of the river near the mouth and use the salt marshes for cover and feeding.

The undeveloped barrier beach system at the mouth of the river (Short Beach) is a regionally important nesting site for least tern (Sterna antillarum), piping plover (Charadrius melodus), a U.S. Endangered species, and American oystercatcher (Haematopus palliatus). Common terns (Sterna hirundo) historically nested here, and roseate terns (Sterna dougallii), a U.S. Endangered species, have been reported from these beaches. Mean tidal range in this area is approximately 7 feet (2 m).

VII. THREATS: While much of the river corridor is undeveloped and in public or protected ownership, there is significant residential development within the drainage basin that impacts water quality in the river through erosion, non-point source pollution and subsurface infiltration from on-site sewage disposal systems. Recreational use of the river corridor and the sand beaches and waters at the mouth is high, often resulting in disturbances to wildlife, especially nesting birds. Of increasing concern is predation and disturbance of nests and birds by unrestrained dogs and cats, as well as human intrusions, on nesting areas of piping plovers and terns on east and west Short Beach. Disturbances to Northern diamondback terrapins during their nesting season on the south side of these same beaches is also a potential problem.

VIII. CONSERVATION CONSIDERATIONS: Attention needs to be focused on protecting the water quality of the Nissequogue River and its significant value to fish and wildlife species, particularly nesting birds and estuarine finfish and shellfish. Protective measures could include stringent regulatory overview and enforcement of existing environmental statutes and regulations, developing and implementing ecologically sound zoning and planning policies and practices, and developing cooperative conservation and management agreements among the various landowners, both public and private, to ensure the maintenance of high water and habitat quality throughout the drainage basin. Beach-nesting birds and terrapins need to be protected from disturbance to ensure the long-term viability of these important populations. In addition to fencing and posting of nesting areas, beach patrols to keep out intruders and remove stray animals need to be established. Efforts should be made to identify and implement those objectives and tasks of the piping plover recovery plan that may be applicable to this area, including habitat restoration and enhancement. There is a significant opportunity to link together the Nissequogue and Connetquot River corridors into a single cross-island wildlife corridor of unfragmented natural landscapes, of particular value for neotropical bird migrants. The development of such a plan should be pursued by governmental agencies, private conservation organizations and private landowners.


Return to table of contents