Chapter 1: The Region
This chapter provides a brief overview of the South Shore Estuary Reserve, characterizes the five estuarine bays and the lands that drain to them, and introduces the many resource management concerns that relate to the different parts of the Reserve.
Estuaries are transition zones between the world's freshwater and marine ecosystems where fresh water mixes with salt water. Long Island's South Shore estuary is a dynamic ecosystem, formed during the past 5,000 years by the interaction of a rising sea level with the glacially-deposited material that makes up Long Island. The entire natural system, including the barrier islands and the 173 square miles of shallow bays behind them, is still changing and evolving in response to wave action, tides, coastal storms, and the continuing rise of sea level. In this estuarine environment, tidal marshes, mud and sand flats, underwater plant beds and broad shallows support microscopic plants and animals which, in turn, support the finfish, shellfish, waterfowl and other wildlife that typify the South Shore estuary.
Overview of the South Shore Estuary Reserve
The South Shore Estuary Reserve is home to about 1.5 million people. The anchor of the region's tourism, seafood and recreation industries, the Reserve stretches from the western boundary of the Town of Hempstead to the middle of the Town of Southampton. South to north, the Reserve extends from the mean high tide line on the ocean side of the barrier islands to the inland limits of the mainland watersheds that drain into Hempstead Bay, South Oyster Bay, Great South Bay, Moriches Bay and Shinnecock Bay.
| The South Shore Estuary Reserve is the anchor of the region's tourism, seafood and recreation industries, and is home to about 1.5 million people. |
Human population growth and burgeoning development in the Reserve, especially since World War II, had and continues to have a dramatic effect on the estuary. Most habitat loss in the Reserve has been the result of the filling of low-lying lands in the western portion of the Reserve for residential and commercial uses. Other development activities, including construction of canals, roads and bridges, have also destroyed or degraded habitats. According to the NYS Department of Environmental Conservation's 1996 Priority Waterbody List, stormwater polluted by elevated levels of fecal coliform bacteria, excessive nutrients and sediment has effected the viability of fish populations in the Reserve's tributaries and has closed over 34,000 acres of hard clam beds in its bays.
For purposes of planning and description, the South Shore Estuary Reserve is conveniently viewed as three subregions: the western bays, Great South Bay and the eastern bays.
The western bays subregion extends from the western boundary of the Town of Hempstead to the Nassau-Suffolk County line, and includes Hempstead Bay and South Oyster Bay and all the lands that drain into them. These embayments are an extensive area of shallow water and salt marsh islands connected by channels and tidal creeks. This portion of the Reserve contains the greatest concentration of salt marsh islands, most of which have been ditched through mosquito control programs. These islands are frequently subject to erosion due to the relatively high tidal range and proximity to heavy commercial and recreational boat traffic. Dredged material islands, over both wetland and shallow water habitats, are also prominent in the subregion.
Almost all of the mainland shoreline in this subregion is bulkheaded, with the most intense development along the shoreline in the western part of the subregion. Much of the original development occurred in the 1950s and 60s as thousands of acres of tidal wetlands were filled to create new home sites. Virtually all mainland tidal wetlands were eliminated in this manner. The western bays also support a variety of benthic macroalgae (seaweeds) and submerged aquatic vegetation (seagrasses), the most important of which is eelgrass. As a result of disease and water quality problems, significant losses of submerged aquatic vegetation beds have also occurred in parts of these bays.
Habitat loss and water quality problems have also had a negative impact on most of the estuarine species in the western bays. Recreational finfish species have declined, as have shellfish populations, which are also impaired by low rates of recruitment. The subregion's significant concentrations of shorebirds, wintering waterfowl and colonial nesting water birds also have been reduced. Most waterbird colonies in the Reserve occur on the islands of the western bays from Hempstead east to Captree. South Oyster Bay and Hempstead Bay are also an important part of the Atlantic Flyway for migrating and wintering waterfowl, particularly brant, with an average of nearly 25,000 waterfowl counted on mid-winter aerial surveys. The importance of the western bays for migrating, wintering and resident coastal birds also needs to be recognized.
The watershed of the western bays is the most densely populated in the Reserve. It exhibits the highest proportion of watershed rendered impervious by roads, parking lots and roofs. Land use south of Sunrise Highway and Merrick Road is highly urbanized and predominantly residential. Intersections along major highways are developed with high density residential, industrial, and/or transportation and utility uses. Land use close to the bays includes parks, nature preserves and protected areas for local and regional recreational purposes. However, residential development along canals, tributaries and the shoreline is increasing the pressure on these natural areas.
Stormwater runoff from this developed landscape is the most significant source of pollution reaching the subregion's tributaries and bays. Elevated levels of coliform bacteria, responsible for the closure of 15,575 acres of shellfish beds in the western bays and the periodic bathing closures of Zachs Bay and Biltmore Beach, is the principal pollutant carried by the runoff, but human waste discharges from vessels, excrement from waterfowl, and discharges from municipal wastewater treatment plant outfalls in the western bays are also contributing sources. Nutrients from these same point and nonpoint sources promote the subregion's extensive mats of seaweeds that are in part responsible for the loss of valuable seagrass beds, while nutrients and sediments in stormwater runoff are held responsible for threatening fish survival and propagation in several of the subregion's tributary streams. Petroleum products are also documented pollutants. Thus water quality in the western bays is affected by both nonpoint and point sources of pollution.
For this subregion, comprehensive efforts are needed to achieve significant improvements in water quality and living resources. Such efforts must include: the restoration of ditched and filled salt marshes; vegetation management in shorebird and waterbird nesting areas; restoration of eelgrass beds; protection and restoration of inland ponds; augmentation of water level and flow in streams; improved boating management; seed clam planting; and educational outreach. Also needed are implementation of management practices as source controls to prevent nonpoint source pollutants from reaching stormwater runoff or from flowing directly into tributaries and bays, and management of polluted stormwater runoff before it reaches those tributaries and bays.
Management of polluted stormwater runoff in areas where the most significant reductions can be gained will correct this major source of nonpoint pollution. One aspect of this effort will be local implementation of stormwater remediation projects with State technical and financial assistance. Such projects will be implemented at roadway crossings of tributaries, at street ends draining to waterbodies, and in parking lots throughout contributing areas. Improvements to municipal stormwater drainage systems that reduce the volume and flow of stormwater runoff to the western bays will be an important element of stormwater management.
Great South Bay is the largest shallow estuarine bay in New York State, with extensive back barrier and tidal creek salt marshes, eelgrass beds, and intertidal flats. Most marshes in the subregion are ditched, with many mainland marshes impaired by fill and bulkheads or restrictions to tidal flow. As the only South Shore bay with major riverine input, Great South Bay's living resources have been significantly affected by diminished tributary water quality. The loss of tidal marshes and other coastal habitats has reduced estuarine productivity and eliminated critical feeding and nursery habitat for finfish, shellfish, shorebirds and colonial waterbirds. Additionally, in the past 25 years, the hard clam harvest in Great South Bay has fallen by more than 93% to record lows.
The watershed of Great South Bay can be described as "developing," in contrast to the more fully "developed" western bays region, and development is generally less intense and open areas more extensive. The primary land use pattern is medium density development with pockets of more intense residential use on fingers of land separated by canals and waterways. Along the shoreline are substantial areas of green space dedicated as parklands and preserves. The intensity of development lessens from west to east within the subregion. Its population has grown over the last decade and is projected to continue to do so over the next twenty years, but at a gradually decreasing rate.
Like the western bays subregion, Great South Bay has extensive impervious surfaces in its watershed. For this reason, polluted stormwater runoff is the primary issue. Nutrients, sediment and coliform bacteria are the principal pollutants carried by stormwater runoff into the subregion's tributaries and ultimately Great South Bay. Vessel waste discharges and waterfowl are also contributors to the bacterial load. Elevated levels of coliform are responsible for the year-round closure of 12,886 acres of shellfish beds in Great South Bay and the periodic closure of three of its bathing beaches. Nutrients and sediments in stormwater runoff threaten fishing, fish propagation and fish survival in the subregion's tributaries and coves. Hydromodifications - alterations of water level and stream flow - and lowering of groundwater levels also have significant effects on fishery resources in tributaries.
For this subregion, efforts to improve water quality are proposed to focus on the management of nonpoint source pollution, especially polluted stormwater runoff. These efforts would include implementation of the management practices recommended in Chapter 2 to prevent nonpoint source pollutants from reaching stormwater runoff or from flowing directly to tributaries and the bay. Management of polluted stormwater runoff in areas where the most significant reductions can be gained would begin to correct this major source of nonpoint pollution. One aspect of this effort would be local implementation of stormwater remediation projects with State technical and financial assistance. Such projects would be implemented at roadway crossings of tributaries, at street ends draining to waterbodies, and in parking lots throughout contributing areas. Parcel acquisition for stormwater management projects, construction of stormwater wetlands, and continued improvements to municipal stormwater drainage systems that reduce the volume and flow of stormwater runoff to Great South Bay will also be important elements of stormwater management.
Projects to restore the living resources of Great South Bay are proposed to focus on: the restoration of ditched, filled back barrier and cove salt marshes, and riverine wetlands; vegetation management in shorebird and colonial waterbird nesting areas; protection of submerged aquatic vegetation beds; augmentation of water level and flow in streams; improved boating and boat maintenance practices; and evaluation of shell augmentation of bay bottoms and seed clam planting.
The shallow eastern bays - Moriches and Shinnecock - are distinguished by the presence of inlets, strong tidal exchanges between the ocean and the bays, and minor inflows of lower salinity water from the Great Peconic Bay through the Shinnecock Canal. Salt marshes and dredged material islands of the eastern bays support significant nesting colonies of terns, gulls, and wading birds. Shallow water areas are highly productive, especially the salt marshes and intertidal flats that fringe the barrier islands and the estuarine habitats around the tributary mouths. The deeper water habitats are composed of sandy shoals and submerged aquatic vegetation beds.
The major land use in the subregion is medium to low density residential, with the greatest concentration of residences along the shoreline and waterways. The area is interspersed with parks, agricultural lands, conservation areas and small clusters of service-oriented commercial establishments, all contributing the rural aspect of the subregion. Population projections indicate that this area will have the largest sustained rate of growth of all the Reserve within the next decade, although the total population and population density are expected to remain the lowest within the Reserve.
Although the watersheds of Moriches and Shinnecock bays are the least developed in the Reserve, elevated levels of fecal coliform bacteria from stormwater runoff, waterfowl and vessel discharges of human waste have closed 6,170 acres of shellfish beds in the bays. Nutrients and sediment in stormwater runoff have affected fish survival in tributaries, and nutrients are suspected of playing a role in the brown tide outbreaks in the subregion.
Agriculture occurs in this subregion to some degree, with potential impacts on water quality from sediments, fertilizers and pesticides. The Agricultural Environmental Management initiative, headed by the Department of Agriculture and Markets, is aimed at minimizing potential pollution from agricultural operations of all types and would help control nonpoint pollution from this source.
The Town of Southampton is exemplary in its efforts to protect and restore the water and living resources of this subregion, but additional work remains. This includes: the restoration of back barrier and mainland fringe salt marshes, especially those formerly connected wetlands where tidal exchange has been halted, and submerged aquatic vegetation beds; the restoration of dredge material islands used for shorebird and colonial waterbird nesting; and the preservation of upland and riparian corridors as protective buffers.
The proposed implementation of management practices will reduce nonpoint source pollution. Management of polluted stormwater runoff in areas where the most significant reductions can be gained is also an important part of achieving high water quality, and would include local implementation of stormwater remediation projects. Such projects would be constructed at roadway crossing of tributaries, at street ends draining to waterbodies, and in parking lots throughout contributing areas. Parcel acquisition for stormwater management projects, construction of stormwater wetlands, and continued improvements to municipal stormwater drainage systems that reduce the volume and flow of stormwater runoff to the eastern bays will also be important elements of stormwater management.