Upper Hudson River Estuary

List of Species of Special Emphasis



I. SITE NAME: Upper Hudson River Estuary


II. SITE LOCATION: The tidal freshwater Hudson River is the portion of the Hudson River from Poughkeepsie north to the Federal Dam in Troy, New York.

TOWNS: Albany, Athens, Bethlehem, Brunswick, Catskill, Clermont, Coeymans, Colonie, Esopus, Greenbush, Greenport, Hyde Park, Livingston, Lloyd, New Baltimore, North Greenbush, Poughkeepsie, Saugerties, Schodack, Stockport, Stuyvesant, Ulster, Red Hook, Rhinebeck

COUNTIES: Albany, Columbia, Dutchess, Greene, Rensselaer, Ulster,

STATE: New York

USGS 7.5 MIN QUADS: Poughkeepsie, NY (41073-68), Hyde Park, NY (41073-78), Kingstown East, NY (41073-88), Saugerties, NY (42073-18), Hudson South, NY (42073-27), Clementon, NY (42073-28), Hudson North, NY (42073-37), Ravena, NY (42073-47), East Greenbush, NY (42073-56), Delmar, NY (42073-57), Troy South, NY (42073-66), Albany, NY (42073-67)

USGS 30 x 60 MIN QUADS: Waterbury, CT-NY (41073-E1), Monticello, NY (41074-E1), Pittsfield, MA-CT-NY (42073-A1), Albany, NY (42073-E1)


III. BOUNDARY DESCRIPTION AND JUSTIFICATION: The significant habitat complex boundary for the upper Hudson River estuary follows the shores of the Hudson River from Poughkeepsie at river kilometer 120 (river mile 75) to the northern inland extent of the tidal Hudson River at Troy Lock and Dam, river kilometer 244 (river mile 152). The boundary of the complex includes the tidal freshwater portion of the Hudson River, including all riverine, open water, and tidal wetlands in this stretch of the river as well as some adjoining uplands and nontidal wetlands. The habitat complex also includes the lower portion of major tributaries feeding into this part of the Hudson, up to the first impediment to fish passage in each tributary. The upper Hudson River estuary and its tributaries encompass regionally significant habitat for anadromous fish and globally rare tidal freshwater wetland communities and plants, and also support other significant fish and wildlife concentrations.


IV. OWNERSHIP/PROTECTION/RECOGNITION: The uplands and shoreline of the upper Hudson Estuary are substantially under private ownership. Underwater lands and formerly underwater lands that have been filled are owned by New York State under the Office of General Services (OGS); some of these parcels have been made state parks and are now under the Office of Parks, Recreation, and Historic Preservation. New York State Parks and Wildlife Management Areas include: Norrie State Park, Clermont State Park, Stockport Middle Ground Island State Park, Castleton Island State Park, Tivoli Bays Wildlife Management Area, Great Vly Wildlife Management Area, and the Rogers Island Wildlife Management Area. The National Park Service owns small parcels of shoreline associated with the Vanderbilt and Franklin D. Roosevelt Homes. Wetlands are regulated in New York under the state's Freshwater Wetlands Act of 1975 and Tidal Wetlands Act of 1977; these statutes are in addition to federal regulation under Section 10 of the Rivers and Harbors Act of 1899, Section 404 of the Clean Water Act of 1977, and various Executive Orders.

The New York State Department of State has designated a number of Significant Coastal Fish and Wildlife Habitats, including from south to north: Poughkeepsie Deepwater, Kingstown Deepwater, Esopus Meadows, Vanderburgh Cove and Shallows, Rondout Creek, the Flats, North and South Tivoli Bays, Esopus Estuary, Germantown-Clermont Flats, Inbocht Bay and Duck Cove, Roeliff-Jansen Kill, Ramshorn Marsh, Catskill Creek, Rogers Island, Vosburgh Swamp and Middle Ground Flats, Stockport Creek and Flats, Coxsackie Island Backwater, Coxsackie Creek, Mill Creek Wetlands, Hannacroix Creek, Coeymans Creek, Schodack and Houghtaling Islands and Schodack Creek, Shad and Schermerhorn Islands, Papscanee Marsh and Creek, and Normans Kill. The New York State Natural Heritage Program, in conjunction with The Nature Conservancy, recognizes several Priority Sites for Biodiversity with the upper Hudson River estuary habitat complex. These sites are listed here along with their biodiversity ranks: Catskill Marsh (B2 - very high biodiversity significance), Esopus Estuary (B2), Kingston Deepwater Habitat (B2), Mill Creek Marsh (B2), Nutten Hook (B2), Poughkeepsie Deepwater Habitat (B2), Rogers Island (B2), Stockport Creek Marshes (B2), Tivoli Bays (B2), West Flats (B2), Astor Point (B3 - high biodiversity significance), Coxsackie Marsh (B3), Gays Point Marsh (B3), Stuyvesant Marshes (B3), Vanderburgh Cove (B3). Tivoli Bays and Stockport Creek and Flats are two of the four sites designated by the National Oceanic and Atmospheric Administration and the New York State Department of Environmental Conservation as part of the Hudson River National Estuarine Research Reserve (along with Iona Island and Piermont Marsh in the mid and lower Hudson River estuary, respectively). The New York State Department of Environmental Conservation, along with state and local partners, is managing the entire Hudson Estuary through the Hudson River Estuary Management Program. The Hudson River Greenway Communities Council is a cooperative effort by local, county, and state governments committed to natural and cultural resource protection, regional planning, economic development, public access, and education.


V. GENERAL AREA DESCRIPTION: The Hudson River estuary can be divided into salinity habitat zones based on average annual salinities: the polyhaline (high salinity) zone from Manhattan north to Yonkers, the mesohaline (moderate salinity) zone from Yonkers north to Stony Point, the oligohaline (low salinity) zone from Stony Point north to about Newburgh/Beacon, and the tidal freshwater zone from Newburgh/Beacon north to the Troy Dam. These salinity zones vary greatly with the season, with the salt front pushed as far south as the George Washington Bridge, river kilometer 19 (river mile 12), during 1994 high spring flows and brackish water extending as far north as Poughkeepsie, river kilometer 120 (river mile 75), during low summer flows. The falls at Troy were probably the extent of tidal influence even before the dam. The Hudson River is partially regulated by the Hudson River-Black River Regulating District, one goal of which is to minimize spring flooding in the upper Hudson (above the Troy dam) and to provide some augmentation flows during the low flow periods. A secondary goal is providing freshwater flows during drought conditions to assist in keeping the salt front below the freshwater intakes at Poughkeepsie. The Hudson River estuary is a tidally dominated system with tidal flows from 10 to 100 times the total freshwater inflows. Salinity influences the distribution and function of both plants and animals within the Hudson Estuary. The distribution of tidal marsh communities and plants in the Hudson is influenced in part by surface water salinity during the growing season; freshwater tidal marsh communities generally occur north of Newburgh-Beacon, brackish tidal marsh communities generally occur south of Newburgh-Beacon, and small remnant salt marshes occur south of Yonkers. Benthic communities vary in distribution depending on bottom water salinity, with a typically marine benthos from Stony Point south dominated by marine worms and crustacea, a mixture of freshwater and marine organisms between Stony Point and Poughkeepsie, and freshwater snails, clams, chironomids, and insects north of Poughkeepsie. Coastal and estuarine fish species tolerate a wide range of salinities, while freshwater species can tolerate only a narrow range to live and reproduce successfully. Anadromous fish species require different salinities at the different phases of their life cycles.

The northern half of the Hudson River estuary from Poughkeepsie north to the Troy Dam constitutes the majority of the tidal freshwater river. In general, the natural depths are greatest in the southern portion of this area, with depths decreasing towards the northern end of the estuary. A shipping channel is maintained to 32 feet mean low water by dredging as far north as the port of Albany, and to 15 feet mean low water from Albany to the Troy Dam. Historically, the upper part of the river from the Troy Dam south to Hudson was a network of shoals, islands, and channels. Beginning in the late 1700s, projects were undertaken to improve the navigability of this stretch of the river by diking and dredging, and by damming the smaller channels to join islands. The completion of the Erie Canal in 1825 increased the urgency for a navigable channel in the Hudson River. The first federal navigation project began in 1834 to construct a system of longitudinal dikes to direct the tidal current. An extensive system of dikes was constructed over the next 100 years between Troy and New Baltimore and further south to Hudson. Since 1910, extensive dredging work has been done to keep the channel first at 12 feet, then 27 feet in 1925 and, beginning in 1954, to its present depth of 32 feet. During this period, dredged material was deposited on shore, on islands, and between islands. The construction of dikes, dredging, and dredged material deposition greatly changed the available habitat in the upper Hudson. Many of the smaller marsh areas are essentially closed off from the main river because dikes were built to serve as railroad beds; Amtrak and New York Central, now Metro North, run on the east shore from New York City to Albany, and Conrail operates from Haverstraw to Esopus on the west shore. The largest changes were in the reduction in shoreline length, loss of intertidal and shallow water habitat, and loss of islands. The uppermost Hudson Estuary from river kilometer 209 to 245 (river mile 130 to 152) has lost nearly all of its historical freshwater wetlands and shallows.

The vegetational and faunal communities found in and along the river depend on both the river's depth and salinity. The deepwater tidal river zone occurs below the depths which support plant growth, i.e., 2-3 meters (6-10 feet) in the turbid Hudson. Primary production in this zone comes only from phytoplankton. These deepwater zones generally have swift currents and rocky bottoms. The two sections of deepwater within the upper estuary are the northern half of Poughkeepsie Deepwater and Kingston Deepwater. The shallow subtidal zone occurs above the deepwater zone and below the mean low tide. This zone occurs in narrow shallow subtidal bands along the deepwater sections of the tidal river, in extensive shallow water beds in the river north of Kingston such as The Flats and Germantown Clermont Flats, in backwater channels such as Coxsackie Island Backwater, and in shallow bays along the river such as Tivoli South Bay and Vanderburgh Cove. This shallow subtidal zone often supports beds of submerged aquatic vegetation (SAV). Characteristic plants include water celery (Valisneria americana), waterweeds (Elodea canadensis and E. nuttallii), naiads (Najas guadalupensis and N. minor), and pondweeds (Potomogeton spp.). Two significant exotic plant species in Hudson SAV communities are Eurasian water-milfoil (Myriophyllum spicatum) and water chestnut (Trapa natans). The intertidal zone in the upper Hudson River estuary consists of freshwater intertidal shore communities along steep rocky shorelines, freshwater intertidal mudflats, and freshwater tidal marsh communities along more gentle sand and mud shorelines. Freshwater intertidal shore communities occur on gravelly or rocky shores, including areas along the extensive rip-rap railroad embankments in the Hudson. Characteristic species include smartweed (Polygonum hydropiperoides), water-hemp (Amaranthus cannibinus), heart-leaf plantain (Plantago cordata), and southern estuarine beggar-ticks (Bidens bidentoides). Intertidal mudflats occurring above mean low water are often sparsely vegetated and are generally dominated by Hudson arrowhead (Sagittaria subulata), with other characteristic species being grass-leaved arrowhead (Sagittaria graminea), stiff arrowhead (Sagittaria rigida), kidney-leaf mud-plantain (Heteranthera reniformis), three-square bulrush (Scirpus pungens), wild rice (Zizania aquatica), water parsnip (Sium suave), softstem-bulrush (Scirpus validus), and a diverse assemblage of periphyton (attached algae) and bacteria. In areas with sandier substrate, three-square bulrush is dominant, with common arrowhead (Sagittaria latifolia), stiff arrowhead, water parsnip, spikerush (Eleocharis palustris), wild rice, water smartweed (Polygonum amphibium), and bur-marigolds (Bidens spp.) present. Freshwater tidal marshes in the Hudson can generally be divided into lower and upper marsh zones. The lower marsh generally experiences large daily fluctuations in water levels and is characterized by peltate-leaved plants (broad leaves on long stalks arising from the plant's base). Characteristic plants include spatterdock (Nuphar advena) in deeper water, interspersed with pickerelweed (Pontedaria cordata), big-leaved arrowhead (Sagittaria latifolia), and arrow arum (Peltandra virginica) in shallower water. The upper marsh is at a slightly higher elevation, is only partially flooded during the daily tidal cycle, and is characterized by an emergent marsh community. Dominant plants are narrow-leaved cattail (Typha angustifolia) and river bulrush (Scirpus fluviatilis), with some areas locally dominated by invasive common reed (Phragmites australis) and exotic purple loosestrife (Lythrum salicaria). In the wetter areas of the upper marsh, the cattail and reed are mixed with wild rice, rice cut grass (Leersia oryzoides), and sweet flag (Acorus americanus). Examples of intertidal mudflat-tidal marsh complexes in the upper Hudson River estuary include Ramshorn Marsh, Vosburgh Swamp, Tivoli Bays, Stockport Flats, and Rogers Island. Inland of the marshes and along the lower portions of some tributaries are forested freshwater tidal swamp communities. Characteristic tree species include green ash (Fraxinus pennsylvanica), black ash (Fraxinus nigra), red maple (Acer rubrum), slippery elm (Ulmus rubra), and American hornbeam (Carpinus caroliniana). Scrub-shrub swamps often occur in association with these forested swamps, with a dense shrub layer, fewer herbaceous species, and an open tree canopy. Common shrubs include honeysuckles (Lonicera spp.) and arrowwood (Viburnum dentatum). Examples of freshwater tidal swamps include Rogers Island, Ramshorn Marsh, Mill Creek Wetlands, and Cruger Island Neck at Tivoli Bays, and those south of Stockport Creek. Many of the swamps, marshes, and flats were formed at the mouths of tributaries. In addition to supporting the important wetland communities occurring at the mouths, tributaries provide freshwater inflow into the Hudson system, spawning habitat for herrings, and overwintering areas for black bass species (Micopterus spp.). The major tributaries in this part of the Hudson and the lengths in kilometers of each tributary available for spawning are, from south to north: Rondout Creek (6.2 km), Esopus Creek (2.1 km), Roeliff-Jansen Kill (9.6 km), Catskill Creek (9.4 km), Stockport Creek including Kinderhook Creek (5.5 km), Coxsackie Creek (6.1 km), Hannacroix Creek (19.9 km), Coeymans Creek (4.8 km), Papscanee Creek (6.2 km), Moordenor Creek (1.6 km), and Normans Kill (3.0 km). These tributaries combined provide about 52 kilometers (32 miles) of available spawning habitat. Numerous smaller tributaries also feed into this portion of the Hudson River.


VI. ECOLOGICAL SIGNIFICANCE/UNIQUENESS OF SITE: The approximately 129-kilometer (80-mile), freshwater, tidal Hudson River is one of the most extensive freshwater tidal river systems in the northeastern United States, and the tidal communities found here are regionally and globally rare. The open water, tidal wetlands, and tributaries in this reach of the Hudson are regionally important anadromous fish spawning habitats, and provide habitat for all life stages of resident freshwater species. This stretch of the river is the most significant spawning grounds (river mile 120 to Troy) of, and part of the wintering habitat for, the federally listed endangered shortnose sturgeon (Acipenser brevirostrum), and is the northern end of the striped bass (Morone saxatilis) spawning area that contributes greatly to the North Atlantic stock. The flats and shoals are among the most productive American shad (Alosa sapidissima) spawning and nursery areas in the region; a substantial commercial and recreational fishery is supported by this population. The numerous creeks and tidal freshwater marshes in this stretch serve as breeding, nursery, and migration corridors supporting waterfowl, shorebirds, and passerine birds. Regionally and globally rare tidal communities include freshwater tidal swamp, freshwater tidal marsh, freshwater intertidal mudflats, and freshwater intertidal shore.

This area supports 94 species of special emphasis, including the following federally and state-listed species. (Living resources and their habitats are dynamic; therefore, the ecological significance and species information presented here may not be complete or up-to-date. State and federal environmental agencies [see Appendix III for office contacts] should be consulted for additional information.)

Federally listed endangered
shortnose sturgeon (Acipenser brevirostrum)

Federally listed threatened
bald eagle (Haliaeetus leucocephalus)

Federal species of concern(1)
southern estuarine beggar-ticks (Bidens bidentoides)
cerulean warbler (Dendroica cerulea)

1Species of special concern listed here include former Category 2 candidates.

State-listed endangered
American waterwort (Elatine americana)
pygmyweed (Tillaea aquatica)

State-listed threatened
osprey (Pandion haliaetus)
northern estuarine beggar-ticks (Bidens hyperborea)
heart-leaf plantain (Plantago cordata)
golden-seal (Hydrastis canadensis)

State-listed special concern animals
least bittern (Ixobrychus exilis)

State-listed rare plants
spongy arrowhead (Sagittaria calycina var. spongiosa)
hirsute sedge (Carex complanata)
Davis' sedge (Carex davisii)
heavy sedge (Carex gravida)
kidneyleaf mud-plantain (Heteranthera reniformis)
smooth bur-marigold (Bidens laevis)
rough pennyroyal (Hedeoma hispidum)
slender knotweed (Polygonum tenue)
sharp-wing monkeyflower (Mimulus alatus)
swamp lousewort (Pedicularis lanceolata)

Prior to 1992, the nutrient-rich Hudson River estuary supported abundant phytoplankton populations that constituted a ready food supply for large populations of freshwater zooplankton, including rotifers, cladocerans, and copepods on a seasonal basis. The introduction and population explosion of zebra mussel (Dreissena polymorpha) has depleted the standing stock of phytoplankton and has impacted other components of the food chain. Benthic invertebrates are relatively abundant but the species diversity is low, primarily oligochaetes and chironomids. The interface region, where fresh water and salt water meet, is particularly important, since major spawning of anadromous and semi-anadromous species takes place here. Eggs and newly hatched larvae are the life stages most vulnerable to the wide range of natural and/or human-caused stresses present in the estuary. Young fish spend days, weeks, or months being nurtured in the saltwater interface area. Such species include Atlantic sturgeon (Acipenser oxyrinchus) and the endangered shortnose sturgeon, alewife (Alosa pseudoharengus), blueback herring (A. sapidissima), American shad, and striped bass. The number of species in the tidal fresh zone is relatively high, due to the mixture of freshwater, semi-anadromous, and anadromous fish species.

Studies evaluating the nontidal portions of tributaries as spawning areas for anadromous and resident species indicate that anadromous fish spawning takes place more or less simultaneously over most of the estuary areas excepting the northern cooler streams, which have a temporal delay. Substrate and water current may be more important factors than tributary size or watershed area. Blueback herring run up through Troy Locks to spawn in the Mohawk and its tributaries and many nontidal areas, but alewife, a major component species in the system, and rainbow smelt (Osmerus mordax) are limited to spawning in the upper estuary north of Poughkeepsie. Only a small percentage of the rainbow smelt population uses the tributaries for spawning. Some species migrate from the estuary to the tributaries to spawn (potadromous). This group includes white perch (Morone americana), yellow perch (Perca flavescens), spottail shiner (Notropis hudsonius), and white sucker (Catostomus commersoni). White suckers are not common in the main estuary and may depend completely on the tributaries for spawning. White perch eggs and larvae occur in all estuary waters, including the tributaries; high densities are found in conjunction with alewife, and any enhancement efforts would probably benefit both species. Darters (Etheostoma ssp.) are a dominant tidal marsh species, probably spawning in large numbers in the tributaries and drifting during their larval stages down to the tidal areas. Black bass (Micropterus spp.) were not found in large enough numbers to determine whether or not the tributaries contribute to their overall production.

Hudson River bass are actively pursued as sport fish in the system. Largemouth (Micropterus salmoides) and smallmouth (Micropterus dolomieui) bass are present, and it has been determined that there are six wintering sites that are extremely important or critical to the maintenance of the Hudson River black bass stocks: Coxsackie Cove, Catskill Creek, Esopus Creek, Rondout Creek, Wappinger Creek, and Fishkill Creek. These areas are also important to a number of other common river species.

Focus Areas:

Poughkeepsie Deepwater is a 22.5-kilometer (14-mile) stretch of deepwater tidal river in the Hudson from river kilometer 109.5 (river mile 68) to river kilometer 132 (river mile 82). This estuarine habitat is formed by a large trench; water depths start at 9 meters (30 feet) and increase at the bottom of the river where they exceed 38 meters (125 feet) in an area known as Crum Elbow at approximately river kilometer 129 (river mile 80). Denser brackish water is overlain by fresh water near the salt wedge and provides an environment that supports assorted marine and estuarine fish. Estuarine-dependent and marine species are found in this area, including Atlantic silverside (Menidia menidia), bay anchovy (Anchoa mitchilli), bluefish (Pomatomus saltatrix), weakfish (Cynoscion regalis), and hogchoker (Trinectes maculatus). This stretch of the river contains several sites that appear to be important for overwintering shortnose sturgeon. The deepwater habitat extends right up to the shorelines in this section, railroads run along both shorelines, and there are only small areas of marsh and flat habitat behind the railroad. The only sizable marsh is found behind the railroad tracks on the east side of the river at Crum Elbow.

Kingston Deepwater habitat is a 9.6-kilometer (6-mile) stretch of the river from Hyde Park to the city of Kingston from river kilometer 137 (river mile 85) to river kilometer 146.5 (river mile 91). It is the northernmost section of deepwater habitat in the Hudson and represents a community type rare in the eastern United States. This segment of river is a nearly continuous deepwater section, with depths greater than 9 meters (30 feet) and some areas reaching 30 meters (100 feet). This deep trough area, overlain by fresh water, provides the northernmost extent of dense saline bottom waters that are introduced by the salt wedge during times of low freshwater flows. The more saline deepwater zone is important to the federally listed endangered shortnose and Atlantic sturgeon as overwintering habitat; it also serves as the upstream extent to which marine fish can travel. The area supports a spring commercial driftnet fishery for American shad as they ascend the river to spawn.

Esopus Meadows is located on the west side of the river adjacent to the Kingston Deepwater site at river kilometer 140 (river mile 87). This 142-hectare (350-acre) shoal area contains intertidal mudflats and subtidal aquatic beds that support a diversity of fish and wildlife species. The shallows provide spawning and nursery habitat for many resident freshwater fish species and a diversity of anadromous species. It is an important feeding area for resident fish and, it is believed, for the endangered shortnose sturgeon, which winter in the adjacent deepwater. Abundant feeding habitat concentrates many waterfowl species, especially during the spring and fall migration periods. Ducks using the open water areas include diving ducks such as greater scaup (Aythya marila), redhead (Aythya americana), canvasback (Aythya valisneria), common goldeneye (Bucephala clangula), and mergansers (Merganser spp.), and dabbling ducks like mallard (Anas platyrhynchos), black duck (Anas rubripes), and blue-winged teal (Anas discors).

Vanderburgh Cove and Shallows is at the confluence of two tributary streams, Landsman Kill and Fallsburg Creek, on the east side of the Hudson River at river kilometer 140 (river mile 87). Like other highly productive shallow areas, it attracts waterfowl as a feeding and resting habitat, especially during migration periods. The cove is isolated from the mainstem by the railroad, but is hydrologically connected in a limited way via two railroad bridges and contains good examples of freshwater intertidal mudflats and freshwater tidal marsh communities. This area is important for fish spawning for both resident freshwater and anadromous fish, and also serves as a feeding and nursery site. The cove and shallows are believed to be a feeding area for the shortnose sturgeon, which winter in the adjacent deepwater. The area is also known as a feeding site for migrating osprey. Southern estuarine beggar-ticks and spongy arrowhead have occurred in this area in recent years.

Rondout Creek habitat includes the lower portion of this freshwater tributary on the west side of the Hudson River at river kilometer 146 (river mile 91), from the mouth 6.4 kilometers (4 miles) upriver to the first dam located just upstream of the New York State Route 213 bridge. The watersheds of Rondout Creek and of the Wallkill River, which feeds into the Rondout, make up the largest tributary watershed in the Hudson River estuary; Rondout Creek is one of the largest freshwater tributaries of the Hudson in terms of flow. The Rondout is an important spawning area for alewife, rainbow smelt, blueback herring, and white perch in the spring. There are also substantial populations of resident species such as brown bullhead (Ameiurus nebulosus), yellow perch, sunfish species (Centrarchidae family), and black bass. The fringing wetlands at the mouth of the creek provide productive feeding sites for migrating waterfowl. Osprey use the clear waters and shallows during their spring migration as a prime foraging area. Several rare plants occur in the marsh or shoreline habitat, including smooth bur-marigold, southern estuarine beggar-ticks, kidneyleaf mud-plantain, spongy arrowhead, heart-leaf plantain, and Frank's sedge (Carex frankii).

The Flats is a 7.2-kilometer (4.5-mile)-long mid-river shoal area in the mainstem of the Hudson River between river kilometer 146 (river mile 91) and river kilometer 154 (river mile 96). It is an important spawning and nursery area for resident freshwater fish, and is a primary spawning site for American shad, which prefer shoals, sandbars, flats, and shallow creek mouth areas. Some striped bass spawning occurs in the deeper water channels on either side of the Flats. Because of the large concentration of young-of-the-year fish using it as a nursery, this area is thought to be important for feeding to shortnose sturgeon and Atlantic sturgeon; these fish also use it in spring and fall to provide for warmer water excursions from their deepwater winter habitat. Dense growths of submerged aquatic vegetation, especially wild celery, provide opportunity for significant concentrations of waterfowl to feed during their migration periods.

Astor Point-Mudder Kill is a small tidal cove, swamp, marsh, and adjacent uplands complex at the mouth of the Mudder Kill, a small tributary to the Hudson on the east side at river kilometer 155 (river mile 96). It supports rare tidal plants that include spongy arrowhead, kidneyleaf mud-plantain, and golden club (Orontium aquaticum). Steep wooded bluffs surrounding the cove and extending out onto Astor Point contain several rare sedge species, including Davis' sedge, heavy sedge, and hirsute sedge.

North and South Tivoli Bays on the eastern shore of the Hudson at river kilometer 158 (river mile 98) comprise the largest freshwater tidal wetland complex surrounded by undeveloped land on the Hudson River. This complex includes approximately 485 hectares (1,200 acres) of wetland communities, including freshwater intertidal mudflats, freshwater intertidal shore, freshwater tidal marsh, freshwater tidal swamp, and shallow water channels. North Bay is a mosaic of freshwater tidal marsh and intertidal mudflats that is dominated by narrow-leaved cattail, whereas the shallows and mudflats of South Bay are dominated by the exotic water chestnut. Small areas of high-quality tidal swamp occur between the bays and at the mouth of Stony Creek. Tributaries feeding into the bays, Stony Creek in North Bay and Saw Kill in South Bay, have a watershed of just over 114 square kilometers (44 square miles). Numerous resident and anadromous fish species use North and South Tivoli Bays as spawning, nursery, and feeding habitat; regionally rare species that are reported to use the area include American brook lamprey (Lampetra appendix), central mudminnow (Umbra limi), northern hogsucker (Hypentelium nigricans), and bridle shiner (Notropis bifrenatus). Shortnose sturgeon may also feed in the channels. Waterfowl use the area for feeding and resting during migration periods. Breeding birds regularly nesting in or adjacent to the Tivoli Bays include Virginia rail (Rallus limicola) and marsh wren (Cistothorus palustris), with probable or possible breeding by American bittern (Botaurus lentiginosus), sora (Porzana carolina), king rail (Rallus elegans), common moorhen (Gallinula chloropus), and mallard. Turtles include a large population of snapping turtles (Chelydra serpentina), as well as spotted (Clemmys guttata), wood (Clemmys insculpta), and map (Graptemys geographica) turtles. Rare plant species that are found in this wetland complex include heart-leaf plantain, golden club, northern estuarine beggar-ticks, southern estuarine beggar-ticks, false pimpernel (Lindernia dubia var. inundata), and sharp-wing monkey flower. Golden-seal is found in the woods adjacent to Tivoli North Bay. A survey of the Lepidoptera of Tivoli North Bay yielded 30 diurnal species (25 butterflies and 5 moths) and 27 nocturnal species (all moths) dominated by the cabbage butterfly (Pieris rapae) and silver spotted skipper (Epargyreus clarus). The regionally rare tawny emperor butterfly (Asterocampa clyton) occurs here. The Tivoli Bays are one of the most intensively studied wetland complexes on the Hudson River and an important component of the Hudson River National Estuarine Research Reserve for research and education.

Esopus Estuary is located at the mouth of the Esopus Creek, a major tributary to the upper Hudson River estuary on the west side of the river in the town of Saugerties at river kilometer 162 (river mile 101). This tidal wetland complex consists of the lower 2 kilometers (1.3 miles) of Esopus Creek to the first barrier and extensive wetlands, including shallow water, intertidal mudflats, tidal marsh, and tidal swamp both north and south of the creek mouth. The creek and shallows are important spawning, nursery, and feeding areas for anadromous fish such as white perch, alewife, blueback herring, smelt, and resident fish species including black bass. The shallow water area at the mouth is especially important for American shad spawning, and the tidal freshwater wetlands that surround this area provide important feeding and resting habitat for migrating waterfowl and osprey. The area adjoins sections of deepwater habitat in the mainstem of the Hudson that are important as post-spawning and wintering habitat for shortnose sturgeon. The wetlands contain occurrences of several rare plant species, including heart-leaf plantain, kidneyleaf mud-plantain, and spongy arrowhead.

Germantown-Clermont Flats is a large, contiguous, freshwater area of shallow and tidal flats, 8 kilometers (5 miles) in length between the towns of Germantown and Clermont in the eastern half of the river at river kilometer 169 (river mile 105). This section is one of the largest continuous areas of shallows and mudflats in the Hudson River estuary. The Germantown-Clermont Flats are in the center of the American shad spawning area and support one of the largest commercial gillnet fisheries for shad on the East Coast. During the spring and fall waterfowl migrations, this area is used as feeding and resting habitat by a large number of diving and dabbling ducks and swans.

Inbocht Bay and Duck Cove is a 283-hectare (700-acre) shallow backwater complex, composed mostly of tidal mudflats and littoral zone, 4.8 kilometers (3 miles) south of the village of Catskill on the west side of the Hudson at river kilometer 174 (river mile 108). The extensive shallow water habitat provides feeding and resting opportunities for some of the largest concentrations of spring and fall migrating waterfowl in the Hudson Valley. This habitat also provides valuable and productive nursery and feeding areas for resident freshwater and anadromous fish. There are exemplary freshwater tidal marsh and freshwater intertidal mudflat communities that contain several rare plants, including northern estuarine beggar-ticks, spongy arrowhead, kidneyleaf mud-plantain, and heart-leaf plantain. Muskrat (Ondatra zibethicus) and snapping turtle populations are noted in this habitat area.

Roeliff-Jansen Kill is a large cool-water tributary with a medium stream gradient located on the east side of the Hudson 9.6 kilometers (6 miles) south of the city of Hudson at river kilometer 175 (river mile 109). The riverine habitat includes 9.6 kilometers (6 miles) of accessible area, extending from the mouth to a natural barrier at Bingham Mills, that is available to migratory and resident fishes. The water quality in the Roeliff-Jansen Kill was found to be high (nonimpacted), based on macroinvertebrate sampling done in 1992. The area is important spawning habitat for alewife, blueback herring, white perch, and resident smallmouth bass and the introduced brown trout (Salmo trutta). At the mouth there are shallows that are important spawning sites for American shad. Small areas of marsh and mudflats at the mouth support at least one rare plant species, the kidneyleaf mud-plantain.

Ramshorn Marsh is a freshwater tidal wetland complex located just south of Catskill Creek and the village of Catskill at river kilometer 179 (river mile 111). This complex is almost 243 hectares (600 acres), occupying about 4.8 kilometers (3 miles) along the western shore of the Hudson. The habitat complex contains one of the largest forested wetlands in a natural condition in the Hudson Valley, and an extensive system of high-quality tidal marsh, intertidal mudflats, and tidal creeks. American shad and black bass use the area as spawning and nursery habitat, as do a number of other fish species. Large concentrations of migrating waterfowl use this area as feeding and resting habitat in the spring and fall. Least bittern are reported to nest in the marshes and the area supports several rare plants, including northern estuarine beggar-ticks, southern estuarine beggar-ticks, kidneyleaf mud-plantain, and swamp lousewort. The National Audubon Society manages a bird sanctuary in the northern portion of the marsh.

Catskill Creek is located in the town of Catskill, on the west side of the Hudson River. The riverine habitat includes the lower 8 kilometers (5 miles) of the river, extending from the mouth to the falls just downstream of the New York State Route 23 bridge; also included is 1.2 kilometers (.75 mile) of Kaaterskill Creek to the first impassable fish barrier. The combined drainage basin for these large, medium to high-gradient streams is 700 square kilometers (270 square miles). Anadromous fish, including alewife, blueback herring, white perch, and resident black bass, spawn in the creek, which affords considerable accessibility when compared with other streams in the area. The upper stretch of the creek is a classic cold-water stream with steep-sided gorges and white water.

Rogers Island is a 263-hectare (650-acre) tidal forested wetland surrounded by extensive shallow water and mudflat habitat, located on the east side of the Hudson River in the town of Hudson at river kilometer 183 (river mile 114). This is one of the largest tidal swamp forests in the Hudson Estuary and in the region; the complex contains exemplary freshwater tidal marsh and freshwater intertidal mudflat communities. The shallows are within the Hudson's concentrated spawning activity zone for American shad, and also support large numbers of spawning and feeding adult and young-of-the-year striped bass, alewife, blueback herring, and white perch. The forest and wetland diversity of the island provides nesting opportunities for green-backed heron (Butorides striatus), American black duck (Anas rubripes), wood duck (Aix sponsa), and a variety of passerine species. Large numbers of shorebirds, waterfowl, and passerine birds use this area during spring and fall migration. The marshes and flats support several rare plant species, including southern estuarine beggar-ticks, smooth bur-marigold, golden club, heart-leaf plantain, swamp lousewort, spongy arrowhead, and Long's bittercress (Cardamine longii).

Vosburgh Swamp-Middle Ground Flats is a freshwater wetland complex extending for 6.4 kilometers (4 miles) along the western shore of the Hudson, upstream from the village of Athens at river kilometer 192 (river mile 119). This 486-hectare (1,200-acre) complex includes mudflats, shallows, freshwater tidal marsh, freshwater marsh, palustrine hardwood swamp, dredged material bank islands habitat, and freshwater creek, i.e., a 0.8-kilometer (0.5-mile) section of Murderers Creek to the first barrier, the Sleepy Hollow Lake Dam. This area's habitat values for fish and waterfowl are similar to those of a number of sites already described. What is unusual is that Middle Ground Flats contains one of the only known bank swallow (Riparia riparia) breeding colonies in the area. Several rare plants occur here, including exemplary occurrences of heart-leaf plantain and southern estuarine beggar-ticks, as well as kidneyleaf mud-plantain and smooth bur-marigold.

Stockport Creek and Flats (includes Stockport Creek Marshes, Gays Point Marsh, Stuyvesant Marshes, and Nutten Hook) is a 648-hectare (1,600-acre) tidal freshwater wetland and tributary habitat complex that extends along the eastern shore of the Hudson for about 11.2 kilometers (7 miles), between the hamlet of Newton Hook (Germantown) and the city of Hudson at river kilometer 195 (river mile 121). Stockport Creek is a major tributary of the Hudson River, formed by the confluence of Kinderhook Creek and Claverack Creek, which together drain a watershed of about 1,295 square kilometers (500 square miles) and provide 4.8 kilometers (3 miles) of accessible habitat to the first barriers on the second order creeks. This is the second-largest unobstructed freshwater tidal stream in the Hudson Estuary drainage. It is an important spawning area for anadromous species such as alewife, blueback herring, smelt, and white perch, as well as resident freshwater species, especially smallmouth bass. The shallow flats area between the shoreline railroad and the dredged channel in the middle of the river is a network of subtidal aquatic beds, freshwater intertidal mudflats (including exemplary occurrences of this community), intertidal shore, tidal marsh, tidal swamp, and dredged material islands. The shallow flats provide an important spawning habitat for American shad, and the littoral zone is a nursery for all the species that spawn in the creek. Marsh-nesting birds that may use the area include green-backed heron, American bittern, American black duck, mallard, wood duck, Virginia rail, sora, fish crow (Corvus ossifragus), and marsh wren, as well as bank swallows and belted kingfishers (Megaceryle alcyon) nesting on Stockport Middle Ground. In addition, one pair of bald eagles has nested or attempted to nest for the past several years. The various wetland habitats also provide feeding and resting areas for large concentrations of migrating waterfowl, particularly canvasback (Aythya valisineria) and, if open water is available, significant wintering habitats especially for redhead (Aythya americana) and canvasback ducks. A substantial map turtle population occurs in the area. Rare plant species found in the tidal wetlands include an exemplary occurrence of heart-leaf plantain, as well as spongy arrowhead, southern estuarine beggar-ticks, smooth bur-marigold, kidneyleaf mud-plantain, Long's bittercress, and golden club. The rare moss Taxiphyllum taxirameum also occurs here. A calcareous cliff community occurs at Nutten Hook. Stockport Flats is an important component of the Hudson River National Estuarine Research Reserve, and is an important site for research and education.

Coxsackie Island Backwater is a shallow vegetated backwater or side channel approximately 2.4 kilometers (1.5 miles) long and 56.6 hectares (140 acres) in size, separated from the main channel of the Hudson by Rattlesnake and Coxsackie Islands along the west shore of the river at river kilometer 201 (river mile 125). Submerged aquatic vegetation and sunken barge hulls provide abundant underwater shelter areas. The backwater is an important resident freshwater fish spawning habitat containing a diversity of species; 31 species of fish were collected in surveys of the area, including spawning by brown bullhead, largemouth bass, and redfin pickerel (Esox americanus americanus). It is one of the most important areas in the upper Hudson River estuary for wintering largemouth bass. The southern portion of this area has a small intertidal mudflat and tidal marsh complex with several rare plant species that include smooth bur-marigold, southern estuarine beggar-ticks, spongy arrowhead, kidneyleaf mud-plantain, and heart-leaf plantain.

Coxsackie Creek habitat is the 2.4-kilometer (1.5-mile) section of the creek from the mouth to County Route 61 on the west bank of the Hudson at river kilometer 203 (river mile 126). This small, medium-gradient, warmwater stream is relatively undisturbed and supports significant spawning habitat for anadromous and resident freshwater fish, including alewife, blueback herring, and white perch. Migratory fish may move as far inland as the village of Coxsackie. The protected tidal cove at the mouth of the creek contains shallow subtidal habitat, freshwater intertidal mudflats, and freshwater tidal marsh habitats that support spawning by American shad, and feeding areas for summering and migrating herons and other wading birds. The wetlands at the mouth of the creek contain several rare plant species, including heart-leaf plantain, southern estuarine beggar-ticks, and kidneyleaf mud-plantain.

Mill Creek Wetlands is a 101-hectare (250-acre) tidal freshwater wetland located on the east side of the Hudson River, 3.2 kilometers (2 miles) north of the hamlet of Stuyvesant at river kilometer 208 (river mile 129). This wetland is bisected by the railroad. The area to the east of the railroad at the mouth of Mill Creek is predominantly a freshwater tidal swamp (scrub-shrub and forested wetland), while the area to the west of the railroad has smaller sections of subtidal shallows, intertidal mudflats, and tidal marshes. The swamp and marshes support a diversity of nesting birds, including green-backed heron, spotted sandpiper (Actitis macularia), belted kingfisher, wood duck, mallard, and blue-winged teal, as well as many passerine species such as veery (Catharus fuscescens), blue-gray gnatcatcher (Polioptila caerulea), white-eyed vireo (Vireo griseus), cerulean warbler (Dendroica cerulea), and swamp sparrow (Melospiza georgiana). Other woodland wildlife species that frequent the area include raccoon (Procyon lotor), muskrat, spring peeper (Hyla crucifer), green frog (Rana clamitans), and gray treefrog (Hyla versicolor). The marsh and high-quality mudflats support rare plants such as kidneyleaf mud-plantain and northern estuarine beggar-ticks, and the shallow water areas support resident and anadromous fish. The Nature Conservancy owns and manages 40 hectares (100 acres), which is most of the forested wetland.

Hannacroix Creek habitat is the lower 2.4-kilometer (1.5-mile) segment of the creek from the mouth to the first natural impassable barrier. The medium-gradient warmwater creek is located on the west side of the Hudson at river kilometer 212 (river mile 132) and has a drainage area of over 155 square kilometers (60 square miles) of relatively undisturbed forested stream corridor. The creek provides important spawning habitat for alewife, blueback herring, and white perch; American shad spawn at the creek mouth where there are abundant shoal areas. The shallows at the mouth also serve as spawning areas for American shad and as feeding and resting sites for migratory waterfowl and waterbirds.

Coeymans Creek is located on the west side of the Hudson River at river kilometer 214 (river mile 133) and is a medium-gradient warmwater stream that drains an approximately 80 square kilometer (50 square mile) watershed. This minor tributary of the Hudson is a tidal cove from the mouth to the falls located just below New York State Route 144, and provides valuable spawning areas for resident freshwater and anadromous species including alewife, blueback herring, white perch, and American shad.

Schodack-Houghtaling Islands complex is a 728-hectare (1,800-acre) area containing a diverse combination of ecological communities that includes floodplain forest, brushlands, cultivated fields, tidal creeks, and mudflats. Located on the eastern shore of the Hudson River 1.6 kilometer (1 mile) south of the village of Castleton-on-Hudson at river kilometer 212 (river mile 132), the complex includes relic islands and side channels of the Hudson that have been altered by the placement of dikes and dredged material, resulting in a peninsula and backwater area connected to the Hudson at only the south end. The aquatic habitat of Schodack Creek, a relic side channel of the Hudson, is a spawning and nursery area for alewife, blueback herring, American shad, white perch, and resident species such as black bass. It is the northern extent for shad spawning in the Hudson, and its fishery productivity draws many osprey to feed here during the spring migration period. The extensive wetlands support nesting habitat for a variety of bird species, including green-backed heron, spotted sandpiper, mallard, American black duck, marsh wren, swamp sparrow, and American woodcock (Scolopax minor). During the peak migration times of spring and fall, the area is used by thousands of waterfowl, shorebirds, and passerine species. Small tidal marshes occur along the shoreline of Schodack Creek.

Shad and Schermerhorn Islands habitat is a 405-hectare (1,000-acre) upland and wetland habitat complex on the western shore of the Hudson at river kilometer 219 (river mile 136) that contains shallow subtidal areas, intertidal mudflats, tidal marsh, floodplain forest, cliffs, and agricultural fields. Dredged material disposal in the 1800s connected Shad Island to the mainland. The two sizeable tributaries in this complex, the Binnen Kill and Vloman Kill, provide quality spawning and nursery habitat for resident freshwater and anadromous species. The wetland supports a small population of a rare plant, northern estuarine beggar-ticks. The Henry Hudson Park site just to the north of Schermerhorn Island contains a couple of rare upland species, including Davis' sedge and rough pennyroyal.

Papscanee Marsh and Creek is the northernmost major wetland area in the Hudson River estuary and is located on the east side of the Hudson just south of the city of Rensselaer at river kilometer 222 (river mile 138). The marsh and backwater extend south for some 6.4 kilometers (4 miles) and are bordered on the east by New York State Route 9J and on the west by the railroad. West of the railroad is a palustrine scrub-shrub swamp. Sections of two tidal creeks, the Moordener and Papscanee, provide spawning and nursery habitat for anadromous and resident freshwater fish as well as for a reported population of map turtles. Besides using this habitat for feeding and resting during migration, many bird species nest here; these include least bittern, green-backed heron, Canada goose (Branta canadensis), American black duck, wood duck, mallard, Virginia rail, common moorhen, spotted sandpiper, common sandpiper, swamp sparrow, marsh wren, and belted kingfisher. The deepwater main channel of the Hudson River bordering Schodack-Houghtaling and Shad and Schermerhorn Islands, and Papscanee Marsh and Creek is spawning area for shortnose sturgeon north to Troy.

Normans Kill, located at the south end of the city of Albany on the west side of the river at river kilometer 227 (river mile 141), is the northernmost of the major tributaries draining into the upper Hudson River estuary and has a drainage area of over 440 square kilometers (170 square miles). The habitat area includes the lower two miles of this large freshwater creek from the mouth up to the falls. The Normans Kill is an important anadromous fish spawning and nursery habitat for alewife, blueback herring, and white perch, and supports a large population of smallmouth bass throughout the year. The water quality in the Normans Kill was found to be slightly impacted, based on macroinvertebrate sampling done in 1992.


VII. THREATS AND SPECIAL PROBLEMS: All activities that degrade water quality in the Hudson River watershed affect the fish and wildlife that use this habitat for various life functions. Water pollution by toxics, chemical, or oil, excessive turbidity, sedimentation, and nonpoint source pollution degrade the quality and functions of this habitat. Toxic contamination also carries with it the long-term effects to the food chain through bioaccumulation and biomagnification and their possible effects on people. Discharge of PCBs into the upper Hudson above Troy has resulted in uptake of PCBs by striped bass and other fish in the Hudson River estuary, with PCB levels generally highest in the upper estuary. Many of the sewage treatment plants in Hudson River communities are at or near capacity, and chlorine discharge from sewage treatment plants is impacting biological communities in the tributaries.

Habitat disturbance by human activities, such as dredging and in-river and shoreside construction, results in impaired water quality that has a significant impact on migrating anadromous fish as they try to reach their spawning areas, and also results in loss of shoreline and wetland habitat. This disturbance impacts many of the other species using this estuary as a nursery site. Human disturbance from recreational activities such as boating, fishing, and hunting is also a threat.

The use, especially nonconsumptive use, of fresh water can disturb the salt wedge dynamics, altering the salinity gradients in the river. The effect is twofold, removing freshwater from the watershed and, after it is used, discharging it artificially into a higher salinity zone. This regime allows for the migration of the salt front much higher in the estuary, which is most evident during the summers of drought years. The natural salinity regime is important to maintaining habitat function and species diversity. Operation of water intakes also has significant impacts on fish populations through impingement of adults and juveniles and entrainment of the critical egg and larval life stages. Another adverse impact can be attributed to discharge of thermally altered water being returned to the river; excessive temperature change over the ambient as much as 10C (17.8F) can affect critical life stages of many of the river's inhabitants. An equally pervasive concern is the lack of minimum freshwater flows in many of the tributaries, making many spawning and nursery habitats only marginal during low flow years. Dams on most of the tributaries effectively remove from the system great numbers of miles of suitable anadromous fish spawning habitat. Transportation has had a major effect on the Hudson; railroad bed construction from as early as the 1840's parallels both banks of the river, crossing all of the tributaries and isolating many of the tidal marsh complexes. Maintenance and rebuilding of railroads, roads, and bridges along the Hudson could adversely impact wetlands and plants, fish, and wildlife. Herbicide use along roads and railroads could destroy rare plant populations; several species of rare freshwater tidal plants occur directly adjacent to these transportation corridors. Nonpoint source pollution in the form of runoff is a constant concern. Dredging necessary to maintain a shipping channel is of grave concern as disposal options become limited; many sites, especially deepwater sites, are not biologically suitable as disposal sites. Deposition of dredged material on or adjacent to rare natural communities and plant populations is a threat. Erosion of mudflat and marsh communities may be a problem at some areas, such as Ramshorn (Catskill) Marsh.

Invading exotic species include Eurasian water-milfoil in subtidal areas, water chestnut in subtidal areas and mudflats, and purple loosestrife and common reed in emergent marsh areas. The zebra mussel (Dreissena polymorpha) is a recent invader of North American freshwater lakes and ponds; zebra mussels now inhabit the Mohawk River and the Hudson River from Albany to Haverstraw Bay, posing a number of threats to the ecosystem and economy of the Hudson. Zebra mussels displace native benthic species, greatly reduce the amount of available phytoplankton, and are responsible for drastic changes in water clarity. These filter-feeding bivalves are capable of significant filtration rates (the volume of water filtered by an individual mussel per unit of time) that reduce available water column food chain production. Phytoplankton and detritus are major food sources for lake and riverine food webs, and excessive removal of phytoplankton and detritus reduces the zooplankton species that feed upon them and can result in fisheries-related impacts. Zebra mussels tend to colonize on rocky substrate in shoal areas, directly impacting these habitats. Their filtering activity tends to increase water clarity; with the increased light penetration, benthic community structure can change dramatically. Zebra mussels outcompete native mussel species for food and space, leading to a decline in native mussel populations. An equally disturbing impact of the zebra mussel infestation is the fouling of water intake systems such as those for drinking water, electrical generation, or industrial use; controlling fouling is problematic, since biocides introduced into the system in mitigation efforts are themselves detrimental to the ecosystem. Zebra mussel infestation also impacts recreational water use, affecting boaters and marina operators. These mussels are readily transported in ballast and on boat hulls; precautions must be taken to help prevent the further spread of this invasive exotic species.


VIII. CONSERVATION RECOMMENDATIONS: Water quality improvement efforts need to continue throughout the watershed. Upgrading sewage treatment facilities and controlling point and nonpoint source pollution should be a major goal throughout the watershed. Water withdrawal activities must be guided by a conservation policy that minimizes impacts by reducing the amount of water withdrawn. Conservation of water resources has a twofold benefit in that it saves water and reduces the amount of water that has to be treated by municipal treatment facilities. Dredging activities should consider spatial and temporal methods that reduce potential impacts to migrating fish populations and to nursery areas. Only comprehensive planning that recognizes the habitat values of this region, balanced with an analysis of the impact to the habitat of each individual proposal taken in the context of cumulative impacts, will result in balanced and effective protection of the watershed and the greater New York Bight ecosystem. Maintaining and rebuilding railroads, roads, and bridges should avoid impacts to wetlands and rare communities and species. Improvements in tidal circulation should be incorporated into maintenance projects. To protect adjacent rare plant populations, herbicides should not be used on roads and railroads along the Hudson River or connected bays and tributaries. There is a great deal of pressure for marina construction on the Hudson River. Such projects should only be approved if they do not impact fish and wildlife and rare communities and plants on the Hudson. Dredging of freshwater intertidal mudflats for marinas and other projects should be avoided. Where erosion of mudflats and/or marshes is occurring, preventing further erosion through the use of geotubes or other methods may be appropriate.

The Hudson River Estuary Habitat Restoration Project being conducted by the U.S. Army Corps of Engineers, along with the New York State Department of Environmental Conservation and the New York State Department of State, has identified fifteen sites as high priorities for restoration along the Hudson River, including eight sites in the upper Hudson River estuary: Schodack and Houghtaling Islands, Mill Creek Wetlands, Hudson North Bay, Hudson South Bay, Ramshorn Marsh, Inbocht Bay and Duck Cove, North Tivoli Bay, and Rondout Creek. A more comprehensive restoration program for the Hudson Estuary, including the tributaries and watershed, should be conducted in concert with this restoration work. Riparian restoration projects along tributaries to the Hudson River are especially important to limit nutrient and sediment loading into the estuary. Further research and carefully monitored restoration of wetlands dominated by exotic and invasive plant species such as purple loosestrife, Eurasian water-milfoil, water chestnut, and common reed are needed. The various agencies and environmental organizations working on the Hudson should continue to cooperate and focus on biodiversity.

The New York State Department of Environmental Conservation recently published an action plan for the Hudson River estuary that outlines priorities and actions needed for managing aquatic resources, preserving upland habitat, open space, and scenery, revitalizing the river-based economy through environmental protection, and promoting stewardship through partnership. Among the recommended actions are: increase monitoring of shad, striped bass, and sturgeon populations; standardize monitoring of fish entrainment and impingement at all power generation facilities to determine and regulate cumulative fisheries impacts; establish biocriteria for monitoring water quality in the Hudson; study the feasibility of restoring habitats at up to 15 locations; amend wetland regulations to more completely protect freshwater tidal wetlands; amend regulations to protect class C and D tributaries to the Hudson; conduct a biodiversity survey and recommend measures for protection; evaluate opportunities to transfer open space lands along the river with a target of 1,619 hectares (4,000 acres); promote the cleanup and appropriate reuse of abandoned and/or contaminated waterfront properties; and identify and quantify sources of contaminants of concern. These proposed actions should be fully supported by New York State and its partners.



Barbour, S. and E. Kiviat. 1985. A survey of Lepidoptera in Tivoli North Bay (Hudson River Estuary). In Polgar Fellowship Reports of the Hudson River National Estuarine Sanctuary Program, 1985, J.C. Cooper, ed. Hudson River Foundation, New York, NY.

Cornell University Cooperative Extension. 1991. The zebra mussel, an unwelcome North American invader. Sea Grant, State University of New York, Coastal Resources Fact Sheet, Stony Brook, NY.

DeVries, C. and C. B. DeWitt. 1986. Freshwater tidal wetlands community description and relation of plant distribution to elevation and substrate. In Polgar Fellowship Reports of the Hudson River National Estuarine Sanctuary Program, 1986, E.A. Blair and J.C. Cooper, eds. Hudson River Foundation, New York, NY.

Elzinga, C. L. 1989. Freshwater tidal wetlands, Hudson River: vegetation description, investigation, and preservation. Master's thesis, Institute of Environmental Studies, University of Wisconsin, Madison, WI.

Green, D.M., S.E. Landsberger, S.B. Nack, D.Bunnell, and J.L. Forney, 1993. Abundance and winter distribution of Hudson River black bass. Hudson River Foundation, New York, NY.

Hudson River Valley Greenway Council. 1991. A Hudson River greenway: a report to Governor Cuomo and the New York State Legislature. New York State Office of General Services, Albany, NY.

Lawler, Matusky and Skelly Engineers. 1991. 1990 year class report for the Hudson River estuary monitoring program. For Consolidated Edison Company of New York. Project no. 115-158.

Limberg, K.E., M.A. Moran, and W.H. McDowell. 1986. The Hudson River Ecosystem. Springer series on environmental management, Springer-Verlag, Inc., New York, NY.

New York State Department of Environmental Conservation. 1996. The Hudson River Estuary management action plan. Hudson River Estuary Management Program, New Paltz, NY. 95 p.

New York State Department of Environmental Conservation and U.S. Department of Commerce NOAA. 1993. Hudson River National Estuarine Research Reserve final management plan. Office of Ocean and Coastal Resource Management, Sanctuaries and Reserves Division, Washington, D.C.

New York State Department of State and The Nature Conservancy. 1990. Hudson River significant tidal habitats: a guide to the functions, values and protection of the river's natural resources. New York State Department of State, Albany, NY.

New York State Department of State. 1987. Hudson River significant coastal fish and wildlife habitats, a part of the New York State coastal management program. Narratives and maps for Poughkeepsie Deepwater, Kingstown Deepwater, Esopus Meadow, Vanderburgh Cove and Shallows, Rondout Creek, the Flats, North and South Tivoli Bays, Esopus Estuary, Germantown-Clermont Flats, Inbocht Bay and Duck Cove, Roeliff-Jansen Kill, Ramshorn Marsh, Catskill Creek, Rogers Island, Vosburgh Swamp-Middle Ground Flats, Stockport Creek and Flats, Coxsackie Island Backwater, Coxsackie Creek, Mill Creek Wetlands, Hannacroix Creek, Coeymans Creek, Schodack-Houghtaling Islands, Shad and Schermerhorn Islands, Papscanee Marsh and Creek, and Normans Kill. New York State Department of State, Division of Coastal Resources and Waterfront Revitalization, Albany, NY.

Schmidt, R.E. and K. Limburg. 1989. Fishes spawning in non-tidal portions of Hudson River tributaries. Hudson River Foundation, New York, NY.

Smith, C.L. and T.R. Lake. 1990. Documentation of the Hudson River fish fauna. American Museum of Natural History, New York, NY.

Smith, C.L. 1985. The inland fishes of New York State. New York State Department of Environmental Conservation, Albany, NY.

State of New York Conservation Department. 1936. A biological survey of the Lower Hudson watershed. Supplemental to twenty-sixth annual report, Albany, NY.

U.S. Department of Commerce, National Oceanic and Atmospheric Administration, Strategic Assessments Branch. 1985. National estuarine inventory: data atlas, volume 1: physical and hydrologic characteristics. National Ocean and Atmospheric Administration, Office of Oceanography and Marine Assessments, Rockville, MD.

Weinstein, L.H. (ed.). 1977. An atlas of the biologic resources of the Hudson Estuary. Boyce Thompson Institute for Plant Research, Inc., Yonkers, NY.

List of Species of Special Emphasis


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