Habitats & Biodiversity

In 2006, the New York State Department of Environmental Conservation (NYSDEC), the New York Cooperative Fish & Wildlife Unit at Cornell University, and the New York Natural Heritage Program partners together to identify and map Significant Biodiversity Areas (SBAs) for the Hudson River Estuary Watershed region, of which Dutchess County is a part [6]. The product of this effort is a critical tool for conservation planning, the Wildlife and Habitat Conservation Framework, which categorized and described regional SBAs. SBAs are large-scale landscape areas that contain high concentrations of biodiversity or unique ecological features. These areas often contribute to and serve as a framework for conservation partnerships and voluntary protection efforts.

Within Dutchess County there are six identified SBAS (Table 1), with the largest being the “Dutchess County Wetlands” Significant Biodiversity Area, spread across ten towns mostly in the western and central parts of the county. In the eastern part of the county is another large and important Significant Biodiversity Area, the “Harlem Valley Calcareous Wetlands” SBA [6].  While SBAs account for much of the range in regional biodiversity throughout the watershed, they should not be interpreted as the only important areas for biodiversity.

• Dutchess County Wetlands
• Harlem Valley Calcareous Wetlands
• Taconic Ridge
• Hudson Highlands
• Hudson River Estuary & Tidal Wetlands (Mid-Hudson River)
• Hudson River Estuary & Tidal Wetlands (Upper-Hudson River)

The Dutchess County Wetlands area is a network of four major wetland complexes that provide important habitat for a variety of amphibian, reptile, and bird species. This area contains the highest diversity of turtles in New York State.  The significant area encompasses several wetlands and their watersheds, and wetland buffer zones that are biologically significant for breeding waterfowl, rare turtles, plants, and other species, as well as intervening areas that contain potential habitat for these species. Floodplain forest communities also exist within this area.

The four separate wetland complexes total 66,000 acres. Two of the complexes (Milan Window and Stissing Mountain sites) feed Wappinger Creek, which then flows along the eastern edge of Poughkeepsie and through Wappinger Falls before flowing into the Hudson River.  The southernmost complex (La Grange/East Fishkill site) contains wetlands that flow into Fishkill Creek, which flows through Beacon and then directly into the Hudson River about 8 miles after leaving the area. The East Park/Hyde Park site encompasses most of Crum Elbow Creek, from its beginning near Wurtemburg to approximately half a mile from the Hudson River.

The Dutchess County Wetlands SBA falls mostly in the lowlands of the Hudson River Watershed and consist mainly of soft sedimentary rocks that are easily eroded and with relatively little topography.  These lowlands tend to facilitate slow moving water and extensive wetland formation. Some of the Dutchess County Wetland sites, particularly Stissing Mountain, are part of the Taconic ranges more resistant metamorphic rocks.  The high variety in rock types helps support a high diversity of flora and fauna.

The wetlands occur in western Dutchess County from Interstate 84 north to the Dutchess-Columbia County line. The SBA can be found within the towns of Beekman, Clinton, East Fishkill, Fishkill, Hyde Park, La Grange, Milan, Pine Plains, Pleasant Valley, Rhinebeck, Stanford, and Wappinger. This area is similar to the USFWS Dutchess County Wetlands Significant Habitat Complex. The four wetland complexes included within this area are, from south to north: La Grange/East Fishkill, East Park/Hyde Park, Milan Window, and Stissing Mountain.

Dutchess County is made up of wetland complexes with many habitats that are unusual or scarce in the region. In addition to being valuable in their own right, these wetlands support a number of local populations of the state listed threatened Blanding’s turtle, one of the few sites for this species in the northeastern United States. These wetlands also support the state-endangered bog turtle. Other rare reptile and amphibian species in this area include the state listed northern cricket frog (the only known occurrence of this species east of the Hudson River), and the regionally rare blue-spotted salamander, marbled salamander, four toed salamander, spotted turtle, wood turtle, eastern box turtle, red-bellied snake, and eastern ribbon snake. The only documented consistent overwintering by golden eagles in the region occurs in this area. Additionally, pied-billed grebe nesting sites and great blue heron rookeries have been documented in the area. The extensive complex of diverse wetlands and upland forests include rich red maple hardwood swamps containing the state rare swamp cottonwood, floodplain forest, deep emergent marsh, rich sloping fen, and medium fen communities. Other rare plant species include prairie sedge and the state listed rare smartweed dodder.

Suburban expansion, along with runoff from nearby roads, agricultural lands, and developed areas, pose the most serious threats to this wetland ecosystem. Further study of the distribution, population status, habitat use, and movement patterns of the bog and Blanding’s turtles, and other species, is needed. Protection of wetlands and their buffer zones, as well as of the movement corridors and road crossings between wetlands, is the highest priority.  Additional inventory is greatly needed, especially with respect to amphibians and reptiles, and mapping of habitat complexes for the Blanding’s turtle.

The Harlem Valley Calcareous Wetlands are composed of the valleys and adjacent ridges in the Taconic Highlands. Wetland communities include red maple-hardwood swamp, floodplain forest, fens, and shallow emergent marsh.  These areas contain high quality habitat for a number of wetland-dependent species and some of the best bog turtle habitat in the Hudson River Valley.  This area also includes adjacent upland ridge and ledge habitat that is especially important for northern copperhead, timber rattlesnake, and five lined skink. The area is made up of two separate wetland complexes totaling 94,000 acres. Both complexes occur in the valleys and adjacent ridges of the southern Taconic Highlands.  The Northeast-Ancram fen complex occurs in Columbia and Dutchess Counties (the northern complex). The portion within the Hudson River Estuary Watershed includes wetlands drained by Punch Brook Swamp, the Noster Kill, and the Roeliff Jansen Kill.  The Great Swamp area (the southern complex) is in Dutchess and Putnam Counties. The portion within the Hudson River Estuary Watershed includes the headwaters of the Croton River and the “South Flow” of the Great Swamp. The portion in the Connecticut River Watershed includes the “North Flow” of the Great Swamp and the headwaters of the Housatonic River.

The majority of the Harlem Valley Calcareous Wetlands biodiversity area consists of Stockbridge Marble, a metamorphic rock composed of the minerals calcite or dolomite. It is formed when limestone is treated to very high temperature and pressure, such as the Taconics’ mountain forming process.  Because of the proximity of this area to the Taconic Mountains, other bedrock components of the area are also mostly metamorphosed rocks (e.g., gneiss, schist, and to a lesser extent, quartzite). These materials are more resistant to erosion than their non-metamorphosed relatives, however their basic (non-acidic) composition maintains wetlands high in strong>pH. Interestingly, because of the nearby Taconic Mountains and the convoluted nature of the bedrock (many layers, wide ranges in metamorphism), water upwellings and springs are common in this region. The result is a preponderance of communities dependent on freshwater upwellings of high pH water, namely fens. Other calcareous regions (Hudson Valley Limestone and Shale Ridges, Dutchess County Wetlands, Esopus Lloyd Wetlands) have much fewer occurrences of fen communities than the Harlem Valley Calcareous Wetlands biodiversity area.  Most of the surficial geology deposits are of glacial origin, such as till, kame deposits, and outwash sand and gravel. Other deposits, such as those in the wetlands, consist of more recent alluvium and organic deposits.

Wetland matrix communities consist of red maple-hardwood swamp and floodplain forest. The upland matrix community tends to be Appalachian oak-hickory forest.  Patch communities include inland Atlantic white cedar swamp, red maple-tamarack peat swamp, rich graminoid fen, rich shrub fen, rich sloping fen, and shallow emergent marsh. Upland patch communities include pitch pine-oak-heath rocky summit, rocky summit grassland, and hemlock-northern hardwood forest.

This area is within the easternmost portion of Dutchess County. Two separate wetland complexes are recognized: the ‘Great Swamp’ from Brewster (Putnam County) north to Amenia, and the ‘Northeast Ancram fen complex’ from Sharon, CT north to Copake Falls (Columbia County). The lowlands occupy a long north-south valley west of the Taconic Mountains called the Harlem Valley (after the railroad line) from which this complex takes its name. Within Dutchess County, this SBA can be found in the towns of Amenia, Dover, North East, Pawling, Pine Plains, Washington, and the villages of Millerton and Pawling. This area is similar to the USFWS Harlem Valley Calcareous Wetlands Significant Habitat Complex. The Great Swamp follows the ridgetops that form the immediate watershed of the wetlands. Great Swamp habitat area includes the wetlands of the Harlem Valley adjacent and proximate to the East Branch of the Croton River, Swamp River, and Ten Mile River; marble hills emerging from the floor of the Harlem Valley; and mountainous slopes on the east and west sides of the Harlem Valley.  There is a drainage divide between the Hudson River and the Housatonic River Watersheds at the village of Pawling where the East Branch of the Croton River flows to the south into the Hudson and the Swamp River flows to the north into the Housatonic Watershed. Although the watersheds are separate, the swamp itself is continuous over both watersheds.

The site encompasses the calcareous wetlands and uplands and ridgetop habitat that support rare reptiles, waterfowl, and raptors, as well as rare plant habitats and communities. The mosaic of calcareous wetlands and adjacent uplands in the Harlem Valley supports regionally significant rare reptile populations and rare calcareous communities and plant species. These calcareous wetlands have truly exceptional concentrations of rare elements. The significant area is considered to contain the best bog turtle habitat in this Hudson Valley region.  Three additional fens within the area were recently found to contain the state endangered (federally listed threatened) bog turtle (Howard et al. 2002). In all, 26 occurrences of bog turtle have been recorded for the Harlem Valley Calcareous Wetlands biodiversity area. This area also contains 11 hibernacula for the state-threatened timber rattlesnake. Other rare animals recorded include Eastern pondmussel and upland sandpiper.  Recently, The Nature Conservancy purchased a very significant rich sloping fen with a bog turtle population, increasing protection of the bog turtles, fen communities, and rare plants present there.

Some of the fens and fen like areas of the site also support regionally rare plants. Great Swamp has several rare calcareous communities and plants. In addition to timber rattlesnake populations, the ledges, talus, acidic rocky crest savannas, woodlands, burn areas, and associated habitats also support northern copperhead and five lined skink. The area supports several regionally rare species such as bladderwort, three toothed cinquefoil, and the dogwood thyatirid moth. The deeper marshes and some of the ponds in this area are important habitats for waterfowl and marsh birds. The extensive wooded swamps support breeding red shouldered hawk and concentrations of migrating warblers. Also notable in the region is an extensive, old growth, hardwoods floodplain savanna with huge ashes and maples, unlike anything else in the region.

Suburban expansion and invasive species are the two central conservation issues in this area. Further study and field surveys of the distribution, population status, habitat use, and movement patterns of the bog turtle, in particular, and other species are needed throughout the entire complex of calcareous wetlands in the tri state region. Protection of wetlands, their buffer zones, and movement corridors connecting wetlands, is a high priority.  These efforts should help direct suburban development to less sensitive areas.

The Taconic Ridge encompasses large areas of contiguous, high quality, northern hardwood forest underlain by complex metamorphic bedrock. It serves as a principal watershed and recharge area for numerous rich fens and associated rare plant and animal species. The Taconic Ridge extends nearly 60 miles along the eastern edge of New York State and is about 12 miles wide at its widest point. Within New York, it covers approximately 78,700 acres. Running along the divide between the Hudson and Connecticut River Watersheds, 53,600 acres of this area fall within the Hudson River Watershed.

Hemlock-northern hardwood forest and Appalachian oak-hickory forest are the most common matrix forest types. Patch communities include pitch pine-oak-heath rocky summit, acidic talus slope wetland, and rocky summit grassland.

The Taconics contain high topographic variability that enhances diversity of community types and associated species. About 450 million years ago (the Ordovician Period), colliding continents caused the formation of a mountain chain the size of the Himalayas in eastern New York and western New England.  These mountains have eroded to what is now the Taconic Range.  The bedrock geology consists of various types of metamorphic rocks; mainly deformed sedimentary rocks that were pushed up from the ocean floor from the advancing continent. These bedrock formations have less buffering capabilities against acid rain and other pollutants than the limestone-rich areas of the Hudson River Estuary corridor.  Communities in the Taconics are likely to be more sensitive to chemical changes in atmospheric deposition. In the upper elevations of the Taconics, the surficial geology is mapped as bedrock, the lower elevations are generally considered to be glacial till. Although till is very rocky, the range of particle sizes (clay and silt all the way to boulders) and the recent exposure/creation of these particles increases the quality of the soil for the plant communities.

The Taconic Ridge is east/southeast of Albany and runs along the border between New York and Massachusetts. In Dutchess County, the SBA is found only in the northeast most corner and forms part of the town of North East. This SBA is notable for its large, contiguous northern hardwood forests.  It is one of the best occurrences of northern hardwood forest communities in the region. It serves a diverse population of resident and migratory bird species as wintering and breeding habitat and as a migratory corridor.  The area also supports regionally rare plant and animal species. Examples include bog turtle and timber rattlesnake, and the globally and state rare Ogden’s pondweed and Hill’s pondweed. During recent biological surveys, a spruce-northern hardwood forest community, which is uncommon in these mountains, was documented on the summit of Berlin Mountain, and a relatively large beech-maple mesic forest was documented at The Knob in New Lebanon and Canaan.

Habitat fragmentation, especially on ridge tops, has been increasing in recent years. Protective measures for these ridge tops need to be explored. This area also needs additional inventory work.

The Hudson Highlands are noteworthy as a relatively undeveloped corridor of forests, wetlands, and grasslands of regional importance to breeding and migratory birds, resident amphibians and reptiles, and rare plants and communities close to the New York City metropolitan area. It is significant for its high concentration of species and communities of special regional emphasis that are dependent on large, unfragmented forest and wetland habitats.

The portion of the Highlands west of the Hudson River includes 190,243 acres within the State of New York and continues west to cross the entire State of New Jersey.  The portion of the Highlands east of the Hudson River totals 215,137 acres in Dutchess, Putnam, and Westchester counties extending from the Hudson River to the Connecticut border.  Ridgelines and valleys, including stream courses and wetlands and lakes are generally in a northeast to southwest alignment. Streams run directly into the Hudson River Estuary, otherwise they generally run into the Ramapo River, which flows south through the center of the Highlands west of the Hudson River.  Major streams east of the Hudson River include Canopus Creek, Peekskill Hollow Creek, and the Croton River.  The Delaware Aqueduct, a major water source for New York City, begins at the West Branch Reservoir within the Highlands.

There is a large diversity of bedrock types in the Hudson Highlands.  These rocks are the oldest in the Hudson River Estuary corridor at 1.3 billion years old; they were formed during the same process that formed the Adirondack Mountains in northern New York.  The high complexity indicates that these layers have been compressed, bent, twisted, and otherwise metamorphosed into erosion-resistant bedrock that form the mountains of southeastern New York.  The folds and faults in the bedrock are generally parallel to each other and generally determine the positions of the ridges and valleys. A large fault, the Ramapo Fault, coincides with the path of the Hudson River and separates the Highlands East from the Highlands West.  The complexity of the Highlands bedrock acts to increase the diversity of the communities and taxa (animal and plant species and subspecies) present by increasing the types and range of minerals and nutrients available. Areas on the surface that are not bedrock outcrops usually consist of glacial till or more recent riverine or lake deposits.

The matrix communities of the Hudson Highlands include Appalachian oak-hickory forest, chestnut oak forest, and oak-tulip tree forest. Recently, a 5,681-acre chestnut oak forest was documented, along with a 2,071-acre Appalachian oak-hickory forest. A large matrix chestnut oak forest of 45,000 acres links the West Point Military Academy with the occurrence of this community in Black Rock Forest and Harriman and Bear Mountain State Parks. Hemlock-northern hardwood forest acts as a large patch community here, in comparison to the more northern Catskill Mountains where it may be matrix forest as well. Dispersed among the matrix forests are patch communities such as pitch pine-oak-heath rocky summit, rocky summit grassland, and acidic talus slope woodland, which may be either large patch or small patch, and red cedar rocky summit, inland white cedar swamp, rich graminoid fen, dwarf shrub bog, highbush blueberry bog thicket, and cliff community, which tend to be small patch communities.

The Hudson Highlands are located in the southern part of Dutchess County, within the Highlands physiographic region. In Dutchess County, this SBA is found within the municipalities of Beacon, Beekman, East Fishkill, Fishkill, and Pawling. This significant area represents one of the largest unfragmented landscape blocks in New York State that creates an important landscape corridor that links the mid-Atlantic states (New Jersey and Pennsylvania) with New England. Along with the continuous and relatively unfragmented forests, the area contains higher elevation ridges and several networks of relatively undisturbed wetlands in the valleys. The ecological significance of this area relates to its large, contiguous forest and wetland habitats and the disturbance sensitive species dependent on these habitats, as well as the diversity of plants, communities, and animals unique to this region. Species populations in the Highlands are indicative of large contiguous areas of undisturbed forest and wetland habitats and include wood turtle, timber rattlesnake, red shouldered hawk, barred owl, warblers and thrushes, black bear, and bobcat.  The rare cerulean warbler, a forest-interior specialist, has a thriving population in the deciduous forests of the Highlands, one of the few concentrations of this species in the state.

There are numerous abandoned mines in the Highlands, many of which are currently being used as winter bat hibernacula. The federally listed endangered Indiana bat and the state special concern eastern small-footed bat are known to occur in the Highlands. Regionally rare ridge top communities include rocky summit grasslands and pitch pine oak-heath rocky summit community.  The great species diversity that is supported throughout the region is an indication of the high ecological value of the area’s habitat.

The most significant threat to the Highlands is the continued conversion and fragmentation of the area’s forests and wetlands.  Conservation efforts should focus on maintaining the unfragmented forest core from the glacial moraine north to the Hudson and across the Hudson to the Connecticut border with linkages on forested ridges to the Delaware River to the south. Additional inventory work is needed.

TThe Hudson River Estuary contains significant freshwater and brackish tidal wetlands, as well as other riverine and estuarine habitats, islands, riparian zones, and important tributaries. These habitats support a high diversity of fish, birds, and mammals. Tidal wetlands exist along the entire reach of the estuary and include some of the rarest ecological communities in the state. Some of the islands contain significant upland communities, including pitch pine-oak-heath rocky summit and hemlock-northern hardwood forest. The Hudson River extends 152 miles from the mouth of the river to the Federal Dam near Troy, New York.  The width of the river ranges from 1/6 mile to 2.5 miles and the surface area at high tide is 82,000 acres. Intertidal wetlands and subtidal shallows consist of 26% or 21,200 acres of this surface area.

The Hudson River Estuary has a four-foot tidal pulse that extends all the way to Troy. In years with average amounts of precipitation falling in typical seasonal patterns, the leading edge of salt water is held downriver between the Tappan Zee and Yonkers during spring runoff.  As runoff slackens during the summer, the salt front pushes northward to Newburgh Bay, and during droughts to Poughkeepsie and beyond. Because of the changing levels of salinity and tidal nature of the Hudson River, species assemblages vary by locality and overall diversity is high. In addition to the tidal riverine community, brackish intertidal flats, brackish tidal marsh, freshwater intertidal mudlflats, freshwater intertidal shore, freshwater tidal marsh, and freshwater tidal swamp all together form a matrix down the shoreline of the river.  Brackish, or lower salinity, tidal wetlands are regularly flooded by ocean water that has been diluted by freshwater from upstream. These wetlands are found south of the Highlands down to Manhattan. Freshwater tidal swamps found along the Hudson are globally rare. Saltwater marshes are now rare in New York Harbor, although they once extended for thousands of acres around Manhattan.  Patch communities within the tidal portion of the Hudson River include calcareous shoreline outcrop, cliff community, and tidal creek.

The Hudson River Valley is broad and gently rolling with a bedrock of shale, siltstone, sandstone, limestone, and dolostone. Most of these are relatively soft sedimentary rocks and easily eroded. These bedrock formations have been eroded away to low plains with the Hudson River flowing through them. Most of the surficial deposits near and within the river are modern river channel deposits. River margins are made nutrient rich as the river carries fresh sediment from the uplands and deposits them along the river’s banks.

The Hudson River Estuary is the portion of the Hudson River extending from the Battery at the southern tip of Manhattan north to the Federal Dam in Troy, New York. Dutchess County municipalities with shorelines on the Hudson River are the towns of Red Hook, Rhinebeck, Hyde Park, Poughkeepsie, Wappinger, and Fishkill; the village of Tivoli; and the cities of Poughkeepsie and Beacon.

The Hudson River is one of the most extensive freshwater tidal river systems in the northeastern United States. The tidal communities found here are regionally and globally rare. Wetland habitats are the cornerstone of the Hudson River Estuary ecosystem because they play a critical role as nursery grounds for fish and shellfish species, nesting sites and migration stops for birds, and sources of nutrients to the food chain. The marshes and tidal flats of the Hudson River Estuary contribute essential nutrients to aquatic and terrestrial food webs that extend throughout the river system and far into the Atlantic Ocean. Besides serving as important habitats, the wetlands that border the Hudson River Estuary perform other valuable services. Pollutants are filtered from water that flows through fresh and saltwater marshes, and these same wetlands buffer valuable real estate from floodwaters and storm surges.  Estuarine plants also help to prevent erosion and stabilize the shoreline.

Estuaries are transition zones from inland freshwater ecosystems to saltwater ecosystems found in coastal environments. Estuarine environments are among the most productive on Earth, creating more organic matter each year than comparably sized areas of forest, grassland or agricultural land. Several measures of the importance of estuaries are that more than half of the commercial fish species caught globally and more than 75% of America’s commercial fish catch spend part of their lives in an estuary.  Key commercial and recreational species such as striped bass, bluefish, and blue crab depend on nursery habitat in the Hudson River Estuary. During recent field surveys, populations of the state-endangered plant Hudson River water nymph were rediscovered in a freshwater intertidal mudflats community.  The entire global range of this plant is limited to the Hudson River Valley; therefore, it is considered endemic. This is the only endemic plant to all of New York State.  Other globally rare plants still found in the Hudson River Estuary include estuary beggar-ticks, Long’s bittercress, and salt-meadow grass. Rare animals of the Estuary include short-nose sturgeon, Atlantic sturgeon and Atlantic needlefish.  Harbor seals are periodically reported, and the Northern diamondback terrapin is present in some of the lower Hudson River Estuary tidal marshes.

The Hudson River Estuary ecosystem has been stressed by multiple activities such as the discharge of raw sewage that leads to high bacterial counts and low dissolved oxygen levels, landfilling that has destroyed valuable wetlands, cooling water intakes that kill millions of fish, and food webs contaminated by toxic chemicals. Among fish of commercial, recreational and ecological importance, the American shad, Atlantic sturgeon, river herring (blueback herring and alewife), American eel, and largemouth bass are in decline. Little is known of the status of blue crab, smallmouth bass, and other species. Striped bass have increased over the last few decades, but fishing pressure in the Estuary and along the Atlantic coast must be carefully managed or it could lower current population levels. Although tidal wetlands have been protected by state and federal law since the 1970s, erosion, sea level rise, changes in salinity, introductions of nonnative species and other factors have caused changes in wetland plant and animal communities over time.

Along the Dutchess County shoreline, the Hudson River Estuary can be further divided into general salinity habitat zones based on average annual salinities:

• Mid-Hudson River Estuary - The productive and regionally significant Mid-Hudson River estuary is generally fresh water in winter and has low salinity in summer. This section encompasses regionally significant spawning migratory and nursery habitat for anadromous, estuarine, and freshwater fish, important winter feeding and roosting areas for the federally listed threatened bald eagle, and globally and regionally rare brackish and freshwater tidal communities and plants. The open water and tidal wetlands in this reach are spawning and nursery habitats and a migratory pathway between the upper and lower estuary for anadromous and resident fish. The habitat contains many unusual features, including deep tidal river habitat that is a rare ecosystem type in the eastern United States, and an important winter foraging area for the bald eagle. The numerous creeks and tidal brackish and freshwater marshes in this stretch serve as breeding, nursery, and migration corridors for fish and wildlife. Iona Island supports important winter roost sites for bald eagles that feed in the adjacent deepwater segment of the river.  Iona island also has several rare plants including Bush’s sedge, slender knotweed, and pinweed. Con Hook Marsh is a small, brackish tidal marsh with several rare plants, including cylindrical headed bulrush, spongy arrowhead, necklace sedge, and pinweed. Con Hook Marsh is also an important wintering area for waterfowl, especially mergansers. Constitution Marsh is a freshwater to brackish tidal marsh and is the largest undeveloped brackish tidal wetland on the Hudson River.  It is a prime breeding and feeding area for marsh nesting birds.
• Upper Hudson River Estuary - The open water, tidal wetlands, and tributaries in the upper reach of the Hudson are regionally important fish spawning habitats for anadromous fish, especially American shad, striped bass, Atlantic sturgeon and shortnose sturgeon, and provide habitat for all life stages of resident freshwater species. The numerous creeks and tidal freshwater marshes in this stretch serve as breeding, nursery, and migration corridors supporting waterfowl, shorebirds, herons, raptors, and passerine birds. Regionally and globally rare tidal communities include freshwater tidal swamp, freshwater tidal marsh, freshwater intertidal mudflats, and freshwater intertidal shore. The Hudson River water nymph, a state-endangered endemic plant, was recently rediscovered in a freshwater intertidal mudflats community from the Upper Hudson River (Howard et al. 2002).

All activities that degrade water quality in the Hudson River Estuary adversely affect the fish and wildlife that use this habitat for various life functions. Water pollution by chemical or oil spills; excessive turbidity; sedimentation; and other point and nonpoint source pollution degrade the quality and function of the estuarine habitat. Toxic contamination has long term effects on the safety of food and the health of consumers due to bioaccumulation and biomagnification. Water quality improvement efforts are needed throughout the estuary.  Upgrades to sewage treatment facilities, control of point and nonpoint source pollution, and contaminant trackdown and clean-up should continue to be major goals throughout the watershed. Full restoration of the hydrologic continuum (wetlands and the river), especially hydrologic connections under the existing railroad beds, and restoration of riparian corridors along the tributaries to the Hudson, will increase available upland habitat, improve the quality of aquatic habitat in the tributaries, and reduce sediment and nutrient input into the Hudson. Improvement of habitat complexes for animals requiring both wetlands and uplands should be encouraged. Additionally, measures to conserve and educate the public about submerged aquatic vegetation (SAV) beds located throughout the estuary should be continued and expanded./