The Barnegat Bay watershed is comprised of a wide diversity of vegetation from coastal dune communities and low-lying estuarine and freshwater wetlands to uplands of pine/oak forests. All of these communities have been affected in some way by human development and related activities.

Undeveloped stretches of the barrier island complex consist of extensive primary and secondary dune habitat along the ocean side and saltmarsh and tidal flats on the backside of the barrier. Island Beach State Park provides the most extensive example of the natural vegetation typical of New Jersey’s barrier islands and spits. Eight plant community zones exist on Island Beach State Park including primary dune, secondary dune, road edge, thicket, freshwater wetlands, bayshore, tidal marsh/estuary, and maritime forest (Table 1). American beach grass (Ammophila breviligata) dominates the primary dune plant community, with the Beach pea (Lathyrus maritimus), Japanese sedge (Carex kobomugi), seaside goldenrod (Solidago sempervirens) and sea rocket (Cakile edentula) also observed in this zone. Seabeach knotweed (Polygonum glaucum), a state listed endangered species, is found at Island Beach and also at Holgate.

The secondary dune community is much more diverse; nearly 30 species of plants have been identified here. Representative species occurring in this community include beach plum (Prunus maritima), bayberry (Myrica pensylvanica), beach heather (Hudsonia tomentosa), pineweed (Hypericum gentianoides), and salt spray rose (Rosa rugosa). The thicket, edge, and freshwater wetland communities have 73, 140, and 55 species, respectively. The bayshore community (22 species) and tidal marsh community (20 species) are much less diverse. American holly (Ilex opaca forma sabintegra), Atlantic white cedar (Chamaecyparis thyoides), White oak (Quercus alba), pitch pine (Pinus rigida), and several other species exist in the coastal woodland or maritime forest community.

While a flourishing plant community exists at Island Beach State Park and to a lesser extent at Holgate, the dune and maritime forest communities of the barrier islands fronting Barnegat Bay have largely been destroyed or substantially altered. The natural dune system has been obliterated along great stretches of New Jersey’s Atlantic shoreline. Dune grass vegetation serves a useful role in stabilizing dunes and protecting beaches against wind and wave erosion. Where feasible, dunes are being reconstructed and revegetated to help impede beach erosion. Barrier island vegetation communities such as maritime shrublands and woodlands provide important stop-over habitat for numerous species of songbirds and raptors migrating along the Atlantic coastal flyway.

The barrier island and mainland shores of Barnegat Bay are fringed with coastal wetlands whose vegetation form and character are largely controlled by the tidal regime and salinity of neighboring bay waters. The saltwater wetlands are subject to high salt concentrations (up to 28-30 ppt), are regularly inundated by the tide, and are typically flat meadowlands dominated by Spartina species. In these tidal wetlands, Spartina alterniflora, S. patens, Juncus gerardi, and Salicornia virginica are the characteristic forms of a New England type salt marsh community (Nixon, 1982; Tiner, 1985). The smooth cordgrass (Spartina alterniflora) dominates low marsh habitat, proliferating in intertidal areas. Smooth cordgrass occurs in two growth-forms, short and tall-form, with a taller form growing along tidal waterways, largely due to better soil aeration and greater supply of available nutrients. Low elevation depressions within the salt marsh are often highly saline due to a combination of impeded drainage, irregular tidal flushing, and intense evaporation (Redfield, 1972). Except for saltworts (Salicornia spp.) and blue-green algae, these "salt pannes" are often largely devoid of vegetation. Salt-meadow cordgrass (Spartina patens), spike grass (Distichlis spicata) and black grass (Juncus gerardi) dominate higher elevation marshes which are only irregularly flooded by saline waters. Shrub species such as salt marsh elder (Iva frutescens) and groundsel tree (Baccharis halimifolia) commonly occur on areas of slightly higher elevation within the salt marsh (e.g., spoil mounds adjacent to ditches) (Sneddon et al., 1995). Common reed (Phragmites australis), narrow-leaved cattail (Typha angustifolia), and bulrushes (Scirpus spp.) commonly occur as a narrow fringe along the upland edge due to decreased tidal flooding, greater freshwater runoff, and thereby lower salinity levels.

Proceeding upstream along some of the larger streams and rivers tributary to Barnegat Bay, salinity levels drop and plant communities diversify. Big cordgrass (Spartina cynosuroides), various sedges (Scirpus spp.), salt marsh fleabane (Pluchae purpurascens), and swamp rose mallow (Hibiscus moscheutos) add greater variety to this brackish marsh community. Tidal freshwater marshes occur where the water becomes fresher (below 0.5 ppt salinity) but still remains tidally influenced (Sneddon et al., 1995). The lower reaches are dominated by forbs such as arrowhead (Sagittaria latifolia), pickerelweed (Pontederia cordata), and arrow arum (Peltandra virginica). Tall stands (> 2 m high) of wild rice (Zizania aquatica) occur along the upper reaches of some tidal freshwater marsh areas. The common reed, an aggressive invader, will colonize and dominate brackish and freshwater tidal marsh areas especially in areas that have been disturbed due to ditching and dredge-spoil dumping (Sneddon et al., 1995; Windham and Lathrop, 1999).

Saltmarshes are characterized by high biomass and organic productivity values. Although standing crops are high, herbivory remains low, resulting in the generation of large amounts of detritus that support detritus-based food chains. The export of a portion of the detritus accumulating in saltmarshes may stimulate productivity in contiguous waters. Leaves and stems effectively increase the substrate surface area for epiphytic flora and fauna, thereby enhancing the primary and secondary productivity of the habitats. The epibiota also provide a rich food supply for fish and invertebrates. A canopy of dense leaves typically found in the coastal wetlands causes lower insolation than in surrounding unvegetated areas. Protected from excessive illumination and insolation, this shaded habitat appears to be beneficial to the benthos. The lateral zonation observed in these wetlands presents a diversity of habitats for the protection and proliferation of epiflora, epifauna, benthic infauna, fishes, birds, and various wildlife species. In the Barnegat Bay-Little Egg Harbor estuarine system, saltmarshes support numerous endangered, threatened or rare species.

Apart from their high production, wetlands are effective in the removal of excess nutrients, metals, and other pollutants from surface waters. The sequestration of nutrients and chemical contaminants is potentially important in water quality protection of estuarine waterbodies. Adsorption of contaminants onto suspended particulates and their subsequent deposition is the primary means of removal. Leaves, stems, and roots reduce wave and current action and facilitate sediment deposition. In addition, the roots and rhizomes bind sediments, stabilize the substrate, and mitigate erosion. Saltmarshes provide natural flood control in the watershed because they tend to slow and hold water. The broad expanses of saltmarshes also stabilize banks and protect the shoreline from other destructive natural and human forces.

The western shores of Barnegat Bay directly border the region of New Jersey known as the Pine Barrens or Pinelands. Situated on the sandy, acid soils of New Jersey's outer coastal plain, the Pine Barrens comprise a landscape of upland pine-oak forests interlaced with a network of "tea-water" streams, dense swamps and ericaceous bogs. The Pine Barrens supports more than 500 species of animals and 800 species and varieties of plants (McCormick and Forman, 1979; Buchholz and Good, 1982; Good and Good, 1984). By no means an undisturbed wilderness area, the Pine Barrens were heavily impacted by bog iron mining, glass blowing, timber harvesting and charcoal-making industries during the 1700's and 1800's. Subsequent to this early industrial period, human disturbance has been comparatively light allowing the regrowth of the extensive forests that give the Pine Barrens its name. Occupying a contiguous area of approximately 450,000 ha, this lightly settled region represents one of the largest tracts of comparatively "natural" landscape remaining on the US eastern seaboard. To protect the Pine Barrens from inappropriate development, legislation was passed in 1978 to create the New Jersey Pinelands National Reserve (NJPNR) (Collins, 1988).

The Pine Barrens landscape is characterized by a complex mosaic of ecological land types: discrete patches or, more often, corridors of cedar and hardwood swamps amidst a background matrix of upland pine and oak forests (Forman, 1979). The upland forests are better characterized by a continuous gradient with pure pitch pine (Pinus rigida) stands on one end grading into pure oak (Quercus spp.) at the opposite (McCormick, 1979). Due to the relatively open canopy of the upland forests, the generally well-developed understories are dominated by either scrub oak (Quercus ilicifolia) or various heath plants such as mountain laurel (Kalmia latifolia), huckleberry (Gaylussacia spp.), and blueberries (Vaccinium spp.). These upland forests in turn grade into pitch pine lowland forests depending on the hydrological regime.

Over the past two hundred years, humans have had a tremendous influence on determining the characteristics of the region’s vegetation communities (McCormick, 1979; Zampella and Lathrop, 1997). The pitch pine (Pinus rigida) dominated forests of southern New Jersey are a fire-dependent vegetation community. The intensity and frequency of fire are among the most important factors determining the structure and composition of Pinelands forest communities (Little, 1979; Forman and Boerner, 1981). Subsequent to fire, pitch pine has the ability to resprout from the basal root crown and along the trunk and limbs (Harshberger, 1916). Oaks also exhibit basal sprouts. Pitch pine also displays the ability to produce serotinous cones which protect the pine seed from the high temperatures of the fire. Subsequent to the fire, the cones then release the seed, permitting pitch pine to rapidly colonize newly available sites suitable for seedlings. Areas of high-fire frequency have been shown to have greater local incidence of serotiny (Givnish, 1981). Under the highest fire frequencies, the upland forest vegetation assumes more of a dwarfed scrubby woodland locally known as pygmy pine plains (McCormick and Buell, 1968; Buchholz and Zampella, 1987). The East Pine Plain, home to a number of unusual prostrate shrubs such as bearberry (Arctospaphylos uva-ursi), pyxie moss (Pyxidanthera barbulata) and the endangered broom crowberry (Corema conradii) (Harshberger, 1916), is on the extreme western border of the Barnegat Bay watershed. It is suggested that changes in fire regime related to more effective fire control may result in changes in landscape patterns, including a gradual transition from pine to oak-dominated forests (Little, 1979; Forman and Boerner, 1981).

The composition of Pinelands wetland plant communities has been extensively studied and described (Roman and Good, 1983; Tiner, 1985; Zampella 1991). Following McCormick’s (1979) widely used classification of community types, Pinelands wetlands include Atlantic white cedar (Chamaecyparis thyoides) swamp forests (Little, 1950, 1951; Olsson, 1979; Roman et al., 1990; Ehrenfeld and Schneider, 1991; Zampella and Lathrop, 1997), broadleaf or hardwood swamp forests dominated by red maple (Acer rubrum) and black gum (Nyssa sylvatica) (Olsson, 1979; Bernard, 1963; Ehrenfeld and Gulick, 1981), pitch pine lowland and pine transition forests (Olsson, 1979; Roman et al., 1985; Zampella et al., 1992), shrubby wetland communities (Olsson, 1979), and herbaceous wetland communities, including both submerged and aquatic vegetation (Olsson, 1979; Morgan and Philipp, 1986). Atlantic white cedar swamps are presently receiving consideration for additional conservation and restoration efforts due to years of indiscriminate logging and past modifications associated with residential development and cranberry bog agriculture.

The unique character of Pinelands flora is widely recognized (Christensen, 1988). Pinelands wetlands support a large portion of the region’s floral biodiversity, including many rare plant species (Fairbrothers, 1979; Snyder and Vivian, 1981; Roman and Good, 1983). Although forested wetlands are dominated by a few tree species, including red maple, Atlantic white cedar, black gum, pitch pine and sweetbay (Magnolia virginica), more than 20 shrub species are found in the understory. Blueberries (Vaccinium spp.), swamp azalea (Rhododendron viscosum), sweet pepperbush (Clethra alnifolia), and greenbrier (Smilax spp.) are generally dominant. Where these forested wetlands merge into the Barnegat Bay coastal region, American Holly (Ilex opaca) often becomes an important component of the sub-canopy. Biologically significant species occurring in wetlands include endemics such as New Jersey rush (Juncus caesariensis) and sand myrtle (Leiophyllum buxifolium), peripheral and disjunct southern species such as turkeybeard (Xerophyllum asphodeloides) and false asphodel (Tofieldia racemosa), and curly grass fern (Schizaea pusilla), a northern peripheral species (Fairbrothers, 1979). The federally endangered swamp-pink (Helonias bullata) and Knieskern’s beakrush (Rhynchospora knieskernii) are also found in Pinelands wetlands.

Benthic macroalgae and vascular plants (seagrasses) comprise the submerged aquatic vegetation (SAV) community of Barnegat Bay, Manahawkin Bay, and Little Egg Harbor. Loveland et al. (1984) recorded 116 species of benthic algae in Barnegat Bay, with the dominant forms being Ulva lactuca, Gracilaria tikvahiae, Codium fragile, Zostera marina, Ceramium fastigiatum, and Agardhiella subulata (Table 2). The benthic macroflora exhibit considerable temporal and spatial variation. Only a few species are common year-round due to the sensitivity of most of the plants to changes in solar radiation and water temperature. Species diversity peaks in late spring, and is lowest in late summer. Although the community composition varies greatly during the year, the dominant species persist.

Many of the benthic macroalgae are unattached to any substrate, and drift along the bottom. Sea lettuce (Ulva lactuca) is consistently one of the most abundant macroalgal species in the estuary. Sea lettuce provides food and shelter for some fauna, but may grow excessively in nutrient enriched areas, causing problems such as hypoxia, smothering of fauna, and lowered aesthethic value. Areas with reduced circulation (e.g., dead-end canals) are particularly prone to the buildup of sea lettuce. In some estuaries (e.g. Delaware inland bays), excess sea lettuce is harvested to reduce impacts on water quality.

Vascular plants occur along the shallow margins of the estuary in waters less than 1 m in depth. Eelgrass (Zostera marina) is the dominant seagrass species in Barnegat Bay, forming dense beds particularly on sandflats along the backside of the barrier island system. Widgeon grass (Ruppia maritima) is of secondary importance, also attaining highest concentrations on the eastern sand flats. Locally dense beds of sago pondweed (Potamogeton pectinatus) appear north of Toms River, with lesser quantities of horned pondweed (Zannichellia palustris), widgeon grass, and eelgrass.

The occurrence of SAV species in the estuary strongly depends on environmental conditions. Each species has its own requirements for and tolerances of physical characteristics, such as temperature, salinity, sediment composition, water velocity, and turbidity. Vascular plants compete with each other and with algae for light, space, and nutrients. The abundance of vascular plants is a function in part of the amount of seeds set the previous year and the successful germination of the seeds. Annuals that grow from rhizomes and tubers (e.g., horned pondweed) may reappear in the same location year after year. The temporal and spatial shifts of SAVs in the Barnegat Bay ecosystem likely result from naturally-occurring cycles (Loveland et al., 1984), although anthropogenic activities such as dredging, nutrient loading, boating, and the use of personal watercraft may be detrimental.

Disease is responsible for significant declines of seagrasses during certain years. For example, McClain and McHale (1997) showed that wasting disease, presumably caused by the protist Labyrinthula zosterae, destroyed about 400 ha of eelgrass beds in Barnegat Bay in 1995. Less disease and SAV destruction occurred in 1996, although as much as 50% of eelgrass leaves exhibited wasting disease at this time.

SAVs have several functional roles in the Barnegat Bay estuarine ecosystem. They provide a substantial amount of primary production for the Barnegat Bay estuary, and serve as critically important habitat for benthic epifauna and infauna. Some organisms graze on SAV (e.g., gastropods, fish, ducks, muskrats). Some benthic macrovegetation (e.g., Zostera marina) also represent valuable spawning, nursery, and feeding grounds for finfish populations in the estuary. They likewise stabilize the benthic habitat by baffling waves and currents and mitigating substrate erosion.

Phytoplankton are free-floating, microscopic plants - unicellular, filamentous, or chain-forming species - inhabiting bay waters. Unicellular forms comprise the bulk of phytoplankton populations in the bay. Based on their size, phytoplankton are classified as: (1) picoplankton (< 5 µm), (2) nanoplankton (5-70 µm), (3) microphytoplankton (70-100 µm), and (4) macrophytoplankton (> 100 µm). Most of the phytoplankton species in the Barnegat Bay-Little Egg Harbor estuary belong to the picoplankton and nanoplankton.

Here, the species composition and dynamics of phytoplankton in the Barnegat Bay-Little Egg Harbor estuary are considered, together with standing crop and primary production. Review of the primary production of phytoplankton logically leads to some discussion of the factors which limit it, namely light, temperature, nutrients, salinity, and zooplankton grazing. As in other temperate estuaries, phytoplankton in the Barnegat Bay-Little Egg Harbor estuary experience seasonal cycles in species composition (succession), biomass, and primary production related to changes in physical, chemical, and biological conditions. Annual successional patterns are well documented for phytoplankton communities in the estuary (Mountford, 1971, 1984).

Barnegat Bay, Manahawkin Bay, and Little Egg Harbor are dynamic waterbodies characterized by a continuum of diurnal, tidal, and seasonal changes in temperature, salinity, and other physical and chemical factors. Light and nutrient availability likewise vary temporally. In addition, water circulation and turbidity, which often exhibit acute perturbations, influence other parameters that may be critical to the success of phytoplankton populations. Hence, the composition of the phytoplankton communities changes through time in response to both abrupt fluctuations and seasonal oscillations in physical-chemical conditions of the environment.

Several factors greatly influence primary production of phytoplankton in the Barnegat Bay-Little Egg Harbor estuary. For example, phytoplankton production is closely coupled to photoperiod, light intensity, and light attenuation in the water column. Light availability is important in initiating seasonal phytoplankton blooms. Barnegat Bay has higher light attenuation coefficients and water column turbidities than other east coast estuaries (e.g., Chesapeake Bay, Delaware Bay, and Narragansett Bay) (Seitzinger and Pilling, 1990) (Figure 1). Particularly in summer, high water column turbidity results in very low light levels at the bay bottom. The phytoplankton populations themselves, as well as suspended sediments and dissolved and particulate organic matter, contribute to water column turbidity.

Phytoplankton alter their reproductive rate, assimilation number, and chemical composition in response to different light intensities. Adaptations of phytoplankton to variable light intensities include a change in the amount of pigments or photosynthetic enzymes in the cells. Phytoplankton have different tolerances to light intensity. Diatoms, for example, are light saturated at a less intense light level than dinoflagellates. Therefore, dinoflagellates may be expected to be more numerous near the estuarine surface.

Temperature affects enzymatic activities (respiration and photosynthesis) and growth rate processes of phytoplankton. In laboratory cultures, the division rates of marine phytoplankton generally increase by two to four times with a 10°C rise in temperature, as long as the temperatures lie within a range favorable to growth (Vernberg, 1975). Temperature also exerts indirect effects on phytoplankton aside from the direct influence it has on their growth, enzymatic activities, and other metabolic processes. For example, in the deeper waters of the estuary (e.g., the Intracoastal Waterway), there may be a tendency for water column stratification to develop during some periods due in part to temperature differences. This can influence phytoplankton growth and productivity in these areas.

Nutrients are necessary for adequate growth and production of phytoplankton. The major nutrient elements include nitrogen, phosphorus, and silicon. Trace elements, such as iron, manganese, zinc, copper, cobalt, and molybdenum, may limit phytoplankton growth if present in insufficient concentrations. However, some trace metals (e.g., copper and zinc) can be toxic to phytoplankton even at low concentrations and, consequently, may hinder their productivity. Certain phytoplankton require the vitamins cobalamine, thiamin, and biotin, as well as other organic compounds.

Nitrogen is the nutrient limiting to phytoplankton growth in the Barnegat Bay estuarine system. Ammonia (lumped here with ammonium), nitrite, and nitrate comprise the principal dissolved inorganic forms of nitrogen. Urea, amino acids, and peptides are important dissolved organic forms. Phytoplankton incorporate both dissolved inorganic and organic nitrogen for growth.

Zooplankton grazing regulates the standing crop of phytoplankton in the estuary. Phytoplankton blooms are superseded by peaks in zooplankton abundance, although the time lag between a phytoplankton bloom and subsequent zooplankton expansion can be quite variable. Variations in the time lag can foster substantial differences in phytoplankton standing crop.

The earliest investigations of phytoplankton in the Barnegat Bay-Little Egg Harbor estuarine system were conducted by Martin (1929) who identified 41 dinoflagellates, five of which he described as new species. Nearly 40 years later, Mountford (1965) reported a serious "red tide" in upper Barnegat Bay during the summer, which stressed fish and shellfish in the area. Silva (1967) described the causative species of that "red tide" as the dinoflagellate Cochlodinium heterolobatum. Mountford (1969, 1971, 1984) subsequently initiated a comprehensive study of phytoplankton communities in the bay.

Olsen (1997) also identified other picoplankton associated with these summer blooms, including a few minute flagellates (Chlamydomonas, Micromonas ? sp.), short cylindrical forms (a chlorophyte Stichococcus or a diatom Minutocellus sp.), and a coccoid (often aggregate or chain-forming) cyanobacterium. Somewhat larger forms were the pennate diatoms Phaeodactylum ?, Nitzschia sp., and flagellates Pyramimonas micron, as well as the chrysophyte Calycomonas ovalis. Several nannoplankton species were also associated with the picoplankton blooms, notably the phytoflagellates Chroomonas spp., C. minuta, Pyramimonas grossii, and Chrysochromulina sp., the diatoms Nitzschia andCyclotella sp. and another chlorophyte Chlorella sp. (coccoid forms > 5 µm). A larger diatom, Cylindrotheca closterium, was sometimes abundant.

The occurrence of Nannochloris and Aueococcus blooms in the Barnegat Bay-Little Egg Harbor estuarine system is of great concern because development of these blooms may be linked to increasing eutrophication of the estuary. As shown by Seitzinger and Pilling (1990, 1992, 1993), Barnegat Bay is currently in a moderately eutrophic state. However, greater incidence or intensity of Nannochloris and Aueococcus blooms in future years would be indicative of potential eutrophication problems in the estuary. Therefore, it is necessary to continue to closely monitor phytoplankton communities in general and blooms of undesirable species in particular. This will be an important step is understanding the factors responsible for initiating such blooms in the estuary. The likelihood of adverse effects on our indigenous shellfish populations and extensive seagrass beds, both valuable resources, certainly requires further investigation.

There have been no recent investigations of zooplankton in the Barnegat Bay-Little Egg Harbor estuary. With the exception of the research of Moser (1997) and McClain and McHale (1997), there also have been no recent studies of the benthic fauna and flora of the system. The most comprehensive work on zooplankton in the estuary was conducted in the 1970's (Loveland et al., 1969; Mountford, 1971; Tatham et al. 1977, 1978; and Sandine, 1984). Detailed benthic surveys, in turn, were performed in Barnegat Bay during the late 1960's and early 1970's (Phillips, 1972; Loveland et al., 1972, 1974; Loveland and Vouglitois, 1984). Zooplankton and benthic assemblages of Little Egg Harbor are largely uncharacterized. The following discussion provides an overview of the structure and dynamics of the zooplankton and benthic communities of Barnegat Bay based on the aforementioned studies.

Zooplankton are volumetrically abundant animals typically several microns to 2 cm in size that drift passively in the water column due to limited capabilities of locomotion. They are classified according to their size or length of planktonic life. Three major size categories of zooplankton are recognized, namely microzooplankton, mesozooplankton, and macrozooplankton. Microzooplankton comprise those forms which pass through plankton nets with a mesh size of 202 µm. Larger zooplankton retained by nets with a mesh size of 505 µm are defined as macrozooplankton, with mesozooplankton comprising those forms intermediate in size.

In regard to the duration of planktonic life, zooplankton may be grouped into three classes: (1) holoplankton, (2) meroplankton, and (3) tychoplankton. Holoplankton are those organisms which spend their entire life in the plankton, in contrast to meroplankton which remain planktonic for only a portion of their life cycle. Tychoplankton refer to small animals, primarily benthic organisms, temporarily translocated into the water column by currents, behavioral activity (e.g., diurnal vertical migration), or other mechanisms.

Zooplankton constitute the principal herbivorous component of estuarine ecosystems. Whereas most zooplankton consume phytoplankton or detritus and serve as an essential link in aquatic food chains by converting plant to animal matter, others are primary carnivores. Some species obtain nutrition by the direct uptake of dissolved organic nutrients. Zooplankton basically gather food via filter feeding or raptorial feeding. Raptorial feeders seize and consume individual cells, removing a few selected prey. Grazing pressure by herbivorous zooplankton commonly regulates the standing crop of phytoplankton populations.

Both biological and physical-chemical conditions in estuaries control the species composition, abundance, and distribution of zooplankton. These microfauna must adapt to varying stresses associated with biological (e.g., scarcity of food, competition, and predation) and physical-chemical (e.g., temperature, salinity, mass movements of water, and dissolved oxygen levels) factors. Estuarine zooplankton are characterized by large variations in abundance and distribution.

In their comprehensive investigations of the zooplankton communities of Barnegat Bay, Loveland et al. (1969), Tatham et al. (1977, 1978), and Sandine (1984) showed that calanoid copepods, particularly Acartia hudsonica, A. tonsa, and Oithona colcarva, dominated the microzooplankton of Barnegat Bay. During the winter months, A. hudsonica was most abundant, and during the summer months, A. tonsa or O. colcarva predominated. Sandine (1984) identified ten other copepod species in Barnegat Bay samples: Paracalanus crassirostris, P. parvus, Oithona similis, Centropages hamatus, C. typicus, Temora longicornis, Pseudocalanus minutus, Pseudodiaptomus coronatus, Tortanus discaudatus, and Labidocera aestiva. Of these forms, P. crassirostris, O. similis, and P. coronatus usually were most abundant.

Zooplankton abundance in Barnegat Bay closely follows that of phytoplankton. Maximum phytoplankton biomass occurs in mid to late winter and in the summer. Phytoplankton numbers peak in the summer. Abundances of microzooplankton, macrozooplankton, and ichthyoplankton reach maxima in the spring or summer. Pulses of zooplankton appear shortly after phytoplankton blooms. For example, Loveland et al. (1969) reported a lag of 27 days between the winter-spring phytoplankton bloom (February) and a subsequent peak of zooplankton (March). The success of zooplankton populations in the estuary is closely coupled to abundances of phytoplankton.

The benthic invertebrate community includes animal populations that live on the estuarine floor or on a firm substrate (epifauna), as well as animal populations that live in the bottom sediment (infauna). There are four size classes of benthic invertebrates: microfauna, meiofauna, macrofauna, and megafauna. The microfauna consist of those bottom dwelling animals which pass through sieves of 0.04-0.1 mm mesh. The meiofauna comprise larger forms captured on sieves of 0.04-0.1 mm mesh, but passing through 0.5 mm mesh sieves. The macrofauna are larger metazoans retained by sieves of 0.5-2 mm mesh. Megafauna are large animals, such as adult crabs and shrimp, typically caught using nets and dredges rather than bottom grab samplers.

Other classifications of the benthic fauna are based on their life habits and adaptations. Nonparasitic species, for example, have been separated into epibenthic, infaunal, interstitial, boring, swimming, and commensal-mutualistic types. Epibenthic animals may attach to a substrate by basally cemented structures (e.g., serpulid polychaetes), holdfasts (e.g., stalked barnacles), or roots (e.g., stalked crinoids). Whereas some epifauna have a sessile habit living permanently attached to a substrate, others are vagile with considerable mobility over a surface. The infauna live in burrows and tubes, or they move freely through unconsolidated sediment. The amphipod, Corophium volutator, builds U-shaped burrows. The fiddler crabs, Uca pugilator and U. pugnax, excavate burrows, which in the case of U. pugilator have single openings that are almost always plugged at high tide on tidal flats. The polychaete, Pectinaria gouldii, constructs a tube of fine sand grains. Nephtys incisa, another polychaete, is motile and traverses through sediment in search of food.

Interstitial animals typically range from 0.2 to 3 mm in size. Many interstitial fauna have an oblong shape which greatly facilitates their movement through the grain interstices below the sediment-water interface. Meiobenthic organisms (e.g., nematodes, gastrotrichs, and harpacticoid copepods) are important interstitial forms.

Animals that bore into hard substrates do so via chemical or mechanical processes. Hence, the boring sponge, Cliona celata, and the boring turbellarian, Stylochus ellipticus, produce bore holes by means of chemical attack, and the woodborers, Bankia gouldi and Teredo navalis, generate burrows mechanically by rasping with their valves to excavate wooden substrates. Urosalpinx cinerea, the common oyster drill, utilizes both chemical attack and mechanical abrasion to bore through the valves of its prey. Examples of swimming benthic invertebrates are species of polychaetes (e.g., Nereis and Nephtys) and bay scallops (Argopecten irradians).

Benthic fauna can also be broadly classified according to their mode of obtaining food. Five categories are recognized: deposit feeders, suspension feeders, herbivores, carnivores-scavengers, and parasites. Loveland and Vouglitois (1984) examined the feeding types of the ten numerically dominant macrobenthic species at the mouth of Stouts Creek in Barnegat Bay. The most abundant deposit feeder at this location was the polychaete, Pectinaria gouldi. The suspension-feeding coot clam, Mulinia lateralis, consistently ranked high in abundance. Of the carnivorous species, Acteocina canaliculata and Mitrella lunata had the highest ranking. Cyathura polita represented the only abundant scavenger. Turbonilla interrupta was the predominant benthic parasitic form. Herbivores were not tabulated, but the grazing periwinkle (Littorina saxatilis), in addition to several other grazing species, occurs in the estuary.

Physical and chemical factors in the estuarine environment clearly influence the functional morphology and behavior of the benthos. A salinity gradient along the longitudinal axis of an estuary affects the abundance and diversity of the benthos, although salinity profiles tend to be more stable in interstitial than overlying waters, and consequently the benthic infauna may be less impacted than the epifauna by salinity variations in the water column. The species composition of benthic communities depends greatly on the sediment type, which often varies appreciably within short distances. Fluctuations in other physical and chemical factors (e.g., dissolved oxygen, temperature, turbidity, wave action, and turbulence) can also alter the structure of the benthic community. The availability of organic matter and oxygen below the sediment-water interface has profound effects on the vertical distribution of the benthos in the sediment column.

Biotic factors, such as predation and species competition, cannot be discounted in studies of the occurrence and distribution of benthic fauna. They also act as limiting factors. Therefore, the mere tolerance of a species to physical and chemical conditions may not provide sufficient explanation for an observed distribution pattern. The occurrence of a species depends on biological adaptation as well. Differences in reproductive seasons, modes of feeding, size, and other biotic factors, for instance, may enable cohabitation of several species in the same general environment.

With the exception of the research of Moser (1997), there have been no recent studies of the benthic fauna of the Barnegat Bay-Little Egg Harbor system. Phillips (1972) and Loveland et al. (1972, 1974) conducted detailed studies of the benthic invertebrate community in western Barnegat Bay between 1965 and 1973 as part of a larger study to assess the effects of the Oyster Creek Nuclear Generating Station on the ecology of the estuary. Loveland and Vouglitois (1984) reviewed results of these investigations. More recently, Moser (1997) examined the distribution and density of benthic infauna at two sites in the Barnegat Bay-Little Egg Harbor estuarine system. A significant, albeit more than 25-year-old, benthic database has only been developed for the western portion of Barnegat Bay between Stouts Creek and Oyster Creek, with comprehensive baseline data lacking for the remainder of the estuary. The benthic community of Little Egg Harbor is largely uncharacterized.

While the absolute abundance of benthic species varied considerably during the 1969-1973 period, the species composition of the community remained quite stable in space and time. Most of the benthic species collected during this period were deposit feeders. From 1970 to 1973, for example, 53-85% of the individuals identified in benthic samples were deposit feeders, 6-47% suspension feeders, and 3-23% carnivores. The numerical dominance of these deposit feeders seems to typify a less stable, medium-successional stage, estuarine soft-bottom benthic community.

Moser (1997) collected benthic infauna at one site on the western side of Little Egg Harbor adjacent to undeveloped saltmarsh near Westecunk Creek and at a second site in a restricted basin in Barnegat Bay near Barnegat Inlet. The second site was located between the open bay and marinas connected to the suburbanized barrier island. Both sampling sites were euhaline, subtidal, and predominantly fine grained. Replicate sediment cores for infauna analysis were collected by divers in August 1993 and March 1994.

Moser (1997) attributed the differences in benthic infaunal communities at the two sampling sites to several factors. At the Barnegat Bay site, a combination of factors probably accounted for the dominance of Capitella spp., including: (1) high total organic carbon concentrations, possibly due to the proximity of marinas and the suburbanized portion of the barrier island; (2) seasonal anoxia leading to an absence of competition; and (3) the proximity of Barnegat Inlet which may act as a conduit for transporting larvae to the site. At the Little Egg Harbor sampling site, the exclusive presence of the opportunistic polychaete species, Cossura sp., was ascribed to occasional low oxygen conditions coupled to high organic carbon concentrations in the sediment.

The estuary supports a rich assemblage of mobile epifauna, including such important groups as crabs, shrimp, and echinoderms. These organisms are more difficult to sample quantitatively than the infauna, and thus have been less well characterized. Nevertheless, they remain ecologically significant in this shallow water system. For example, sand shrimp (Crangon septemspinosa) and grass shrimp (Palaemontes vulgaris and P. pugio) provide forage for resource species and predators on smaller fauna. Mysid shrimp (Neomysis americana) commonly occur on or near the bottom, but are less closely associated with it than the aforementioned taxa. These diminutive shrimp also constitute a valuable food source for recreationally and commercially important finfish in the estuary.

Mud crabs (i.e., Neopanope texana, Panopeus herbstii, and Rhithropanopeus harrisii) are common on the bay bottom, and may be a factor in limiting recruitment of harvestable clams. These crabs may consume large numbers of juvenile hard clams (Mercenaria mercenaria) in the estuary. They may have contributed to the decline in landings of hard clams in the system during the 1990's.

Other notable members of the mobile epifauna are horseshoe crabs (Limulus polyphemus), gastropods (e.g., Busycon canaliculatum, B. carica, and Polinices duplicatus), and starfish (Asterias forbesi). These species also consume hard clams. Hence, the gradual reduction in the abundance of hard clams during the 1990's may be impacting these populations as well, although no recent quantitative sampling has been conducted in the estuary to verify such a relationship.

Shafto (1974) and Loveland and Shafto (1984) investigated the fouling community of the estuary, concentrating on the settlement and growth of epiflora and epifauna on man-made materials. Shafto (1974) recorded 38 species (21 mobile and 17 sessile forms) of fouling organisms from more than 100 exposure panels deployed in Barnegat Bay. Bacteria, algae, amphipods, barnacles, bryozoans, molluscs, polychaetes, sponges, and tunicates are the principal components of the fouling community. Although both sessile and mobile biofouling populations existed in the bay, the dominant forms were sessile, with Balanus eburneus and Hydroides dianthus being most abundant. These two species plus Bowerbankia gracilis and Membranipora sp. consistently dominated the fouling community in most regions. Maximum settlement occurred from May to October when food supply and water temperature are optimum, and minimum settlement, from November to April. In areas with salinities below 15 ‰, B. eburneus, B. gracilis, Membranipora sp., Polydora ligni, and Melita nitida predominated. Where salinity exceeded 15 ‰, Botryllus schlosseri, Corophium sp., H. dianthus, and Molgula manhattensis were most abundant.

The species composition of the fouling community varied monthly but repeated seasonally in response to predator-prey interactions, cycles of reproduction and settlement, and seasonal changes in environmental conditions. Therefore, some fouling species, such as Botryllus schlosseri and Hydroides dianthus, dominated during the summer, whereas others, such as Balanus improvisus and B. balanoides attained peak abundance in winter. Biofouling algal populations, which are seasonally abundant, can affect abundance of the biofouling fauna. Codium fragile, Enteromorpha intestinalis, Polysiphonia harveyi, and Ulva lactuca are the most important biofouling flora in the system.

Larval dynamics strongly influenced the complexity of the fouling community. The settlement of biofouling larvae was responsive to mud and detritus accumulation on substratum surfaces and to illumination. Some biofouling larvae (e.g., Corophium sp., Melita nitida, Polydora ligni, Sabellaria vulgaris) appeared to be photopositive, setting most densely on the upper surfaces of wooden substrata. Others (e.g., Balanus eburneus, B. schlosseri, B. gracilis, Hydroides dianthus, Membranipora sp., and Molgula manhattensis) settled most heavily on the lower surfaces of substrata and seemed to be photonegative. The observed distribution and density patterns of adult biofouling populations in the estuary were thought to be the result of attraction of larvae to microflora, bacteria, substratum chemicals, and the same species, as well as avoidance of interspecific competition.

Investigations of the boring community of the estuary during the 1970's and 1980's revealed the occurrence of four teredinid species: Bankia gouldi, Teredo navalis, T. bartschi, and T. furcifera (Richards et al., 1984). Bankia gouldi was the dominant teredinid along the western perimeter of Barnegat Bay, and T. navalis was the dominant form along the eastern perimeter. Teredo bartschi and T furcifera, tropical-subtropical woodboring species which are no longer found in the estuary, became adapted to areas affected by thermal discharges from the Oyster Creek Nuclear Generating Station during the 1970's and 1980's. Of the four teredinid species identified in the estuary, B. gouldi had the greatest spatial distribution.

Spawning of teredinids in Barnegat Bay occurred primarily during the warmer months of the year (April through October). Successful settlement of larvae on wooden surfaces took place between July and December. Maximum teredinid abundance and destruction developed during the summer season, but most teredinids did not survive the winter.

Survival, growth, abundance, and intensity of attack of teredinids appeared to be dependent primarily on water temperature, salinity, presence of humic material, and the availability of untreated (noncreosoted) wood. Of these factors, water temperature and the presence of a wooden substratum probably exerted the greatest influence on the behavior of teredinids. Low temperatures during the winter precluded spawning, arrested growth, and caused substantial mortality of the adult populations. The few adults that survived the winter months perpetuated the populations during the summer when more optimum water temperatures induced spawning and rapid growth, resulting in increased damage to wooden structures.

Aside from the teredinids, the crustacean borer Limnoria sp. caused damage to wooden structures in the southern portion of Barnegat Bay. Limnoria sp. destroys the outer portion of wooden structures, and its impact can be considerable. Consequently, untreated wooden pilings are typically reduced to an hourglass structure under attack by Limnoria sp.

Benthic fauna are a major component of the Barnegat Bay-Little Egg Harbor estuarine food web. In shallow estuaries, benthic fauna may rival zooplankton in their ability to regulate the abundance of phytoplankton. However, since Barnegat Bay and Little Egg Harbor presently have low stocks of large filter feeders (e.g., clams, oysters, and scallops), the capability of the benthos to control phytoplankton abundance is lessened. Benthic fauna are also important in nutrient regeneration. In addition, key taxa are potentially valuable for assessing water quality and habitat conditions. Some benthic populations are economically important. For example, hard clams are of recreational and commercial importance. Boring species have a more dubious distinction in that they can cause damage to man-made structures, and fouling assemblages increase maintenance requirements.

The overall health of the system is closely coupled to the abundance, distribution, and diversity of benthic fauna in intertidal and subtidal habitats. Clearly, benthic fauna are extremely important to the structure and function of biotic communities in the estuary. Future management strategies, therefore, must consider the development and implementation of restoration and maintenance programs to improve the health and long-term viability of benthic habitats and communities in the estuary.

Finfish studies of the ichthyofauna of Barnegat Bay were conducted by Marcellus (1972) during the late 1960's and early 1970's and by several investigators from September 1975 through August 1981 (Tatham et al., 1977, 1978; Vouglitois, 1983; Tatham et al., 1984; Vouglitois et al., 1987) using trawls, seines, gill nets, or bongo nets. Most samples were taken along the western perimeter of the bay, with fewer collections made near Barnegat Inlet and extensive shoals in the eastern segment. Tatham et al. (1984) and Vouglitois et al. (1987) explain the sampling programs and life-history studies performed during these studies. More recently, Able and Fahay (1997) and Wilson and Able (1997) examined additional aspects of finfishes in the estuary.

According to Tatham et al. (1984), the fish community of Barnegat Bay is characteristic of mid-Atlantic estuaries and embayments, in general, and representative of the fish communities of New Jersey coastal bays. Only a few species numerically dominate the fish community of the estuary. For example, the bay anchovy (Anchoa mitchilli), Atlantic silverside (Menidia menidia), fourspine stickleback (Apeltes quadracus), spot (Leiostomus xanthurus), and winter flounder (Pseudopleuronectes americanus) constituted more than 90% of the total number of fish sampled in bay collections from September 1975 through August 1978, being responsible for 57.9, 22.1, 4.2, 3.8, and 1.9% of all individuals, respectively (Figure 2). During this period, 107 species belonging to 57 families were identified in the bay (Table 6).

Based on their spatial and temporal occurrence and their relative abundance within or outside the bay, the finfish were classified into five general assemblages: (1) residents (20 species) occupying the estuary year-round; (2) warm-water migrants (34 species) abundant primarily from April through November; (3) cool-water migrants (12 species) present from November through April; (4) marine strays (42 species); and (5) freshwater strays (7 species). Resident species comprised 31 % of all fish collected, warm-water migrants 65%, cool-water migrants 3%, and marine and freshwater strays 1% (Figure 3). Most individuals were either small forage fishes, principally resident in the estuary, or young and juveniles of marine species present only seasonally. The diversity of fishes peaked from late summer through mid-fall (41 to 47 species per month). Warm-water migrants accounted for an increase in diversity from spring through fall. The number of species dropped sharply in the winter when only a few residents and cool-water migrants (13 species) inhabited the bay.

Migration and finfish distribution in the estuary are strongly affected by salinity, seasonal water temperature changes, spawning habitat, and food availability. Both resident and migratory fishes use the bay as a spawning area, with most reproduction triggered in the spring, summer, and winter. Anchoa mitchilli, Gobiosoma spp. (gobies), Menidia menidia, and Syngnathus fuscus (northern pipefish) were the main spawners during the spring and summer months, and Ammodytes sp. (sand lance) and Pseudopleuronectes americanus were the principal spawners during the winter months. From May through October, the young of most resident species (19 of 20 species) and the young of many warm-water migrants (21 of 34 species) utilized the estuary as a nursery area.

Examples of juvenile marine species which heavily utilize the estuary as a nursery during the summer months of the year are Pomatomus saltatrix (bluefish), Brevoortia tyrannus (Atlantic menhaden), Cynoscion regalis (weakfish), and Leiostomus xanthurus (spot.). Larval and young stages of Ammodytes americanus, Micropogonias undulatus, and Pseudopleuronectes americanus use the estuary as a nursery in the winter and early spring, as do young Apeltes quadracus. Immature P. americanus live in the bay year-round. Wilson and Able (1997) expressed concern that juvenile P. americanus readily use marina habitats in the estuary and may be exposed to hydrocarbons and heavy metals in these areas. Table 7 specifies the usage of Barnegat Bay by residents, warm-water migrants, and cool-water migrants. Seagrass beds, saltmarshes, and tidal creeks clearly provide important habitat for finfishes in the estuary. Each of these major habitats, which can contain important "micro-habitats", are often used by a unique assemblage of fish species (Rountree and Able, 1993; Able et al., 1996), thereby contributing to the diversity of species in Barnegat Bay. In a recent analysis of the temporal and spatial variation in fish species composition in Little Egg Harbor, the majority (98.7%) of three spine stickleback and most naked gobies (76.1%) and weakfish (68.6%) were captured in a freshwater creek; all silver perch, the majority (99.0%) of four spine stickleback, and most (75.0%) lizardfish were captured in seagrass; and all hakes (Urophycis spp.), skates, windowpane, and the majority (94.5%) of smallmouth flounder were collected in deeper-water channels (Jivoff and Able, in review).

The absolute abundance of fishes in Barnegat Bay is highest from May through November due to the arrival of warm-water migrants and the recruitment from spawning populations in the estuary. Far fewer individuals are present during the winter, although an increase in abundance becomes evident as early as March or April. Larvae and juveniles attain maximum numbers in the spring and summer months. Annual variations in absolute abundance of 50 to 100% are not unusual. Fluctuations in environmental conditions that influence reproductive success may be responsible for such large variations in abundance.

The bay anchovy and Atlantic silverside are the two most abundant species in the bay. During their three-year survey, Tatham et al. (1984) showed that the bay anchovy and Atlantic silverside were the first and second most abundant species in the bay, respectively. According to Vouglitois et al. (1987), the bay anchovy accounted for 27% of the total finfish catch from 1975 to 1981. This species is the mainstay of Barnegat Bay forage fish and a ubiquitous inhabitant of the creeks, lagoons, and local embayments of the system. The maximum abundance of bay anchovy occurs between May and October each year, but an offshore and southerly migration from the estuary to continental shelf wintering grounds takes place in the fall. Similarly, the Atlantic silverside migrates to deeper waters of the estuary or coastal ocean in the winter.

A bimodal peak in the abundance of trawl catches of bay anchovy has been documented; an initial peak corresponds to May or June and a second, often larger peak takes place in September or October. Bay anchovy eggs and larvae numerically dominate ichthyoplankton samples in the estuary, comprising up to 98 and 56% of the annual egg and larval catches, respectively. Little Egg Harbor plays a key role in determining the abundance and diversity of fish in Barnegat Bay because it offers a natural connection (Little Egg Inlet) to oceanic environments and contains a variety of habitats for various life history stages of fish. As a result, larval fishes from a variety of environments, are transported into the estuary and immediately find suitable settling habitats (see Witting et al., 1999). In a 1976 survey of Manahawkin Bay and Little Egg Harbor, the New Jersey Department of Environmental Protection and Energy registered 66 species of finfish. The ten most abundant species in this survey were the bay anchovy, Atlantic silverside, fourspine stickleback, mummichog, and inland silverside (Menidia beryllina), Atlantic menhaden (Brevoortia tyrannus), banded killifish (Fundulus diaphanus), silver perch (Bairdiella chrysoura), winter flounder, and white perch (Morone americana). The five most abundant species comprised up to 80% of all specimens for all gear types (U.S. Fish and Wildlife Service, 1996).

A more recent survey in Little Egg Harbor produced very similar results in terms of both the number (67 species in 28 families) and composition of species captured (Szedlmayer and Able, 1996). There was considerable temporal (among months) and spatial (among five sites; 2 seagrass beds, 1 freshwater creek, and 2 deep-water channels) variation in fish abundance and species diversity, indicating that these areas offer critical habitat to a variety of species and life history stages of fish (Jivoff and Able, in review). Finfish collections of Wilson and Able (1997) were dominated by shallow water estuarine residents or juveniles of species that utilized the area as nurseries. Included among the most abundant species were the Atlantic silverside, fourspine stickleback, sheepshead minnow (Cyprinodon variegatus), naked goby (Gobiosoma bosc), and winter flounder. However, strays from more southern waters were also recovered (e.g., Chaetodon ocellatus, Chasmodes bosquianus, Hypsoblennius hentz, Lactophrys sp., Lutjanus griseus, and Monacanthus sp.). In regard to the relative abundance of fishes in Barnegat Bay, the ten most common species recorded in numerical order are the bay anchovy, Atlantic silverside, fourspine stickleback, spot, winter flounder, inland silverside, northern pipefish, mummichog (Fundulus heteroclitus), bluefish, and oyster toadfish (Opsanus tau) (U.S. Fish and Wildlife Service, 1996). The bay is an important nursery area for some of these species (e.g., spot, bluefish, etc.). It also provides an important habitat for summer spawners (e.g., bay anchovy, Atlantic silversides, gobies, and northern pipefish) as well as winter spawners (e.g., sand lance).

In summary, the community structure, seasonal patterns, and populations trends of the finfish community of the Barnegat Bay-Little Egg Harbor estuarine system are similar to those of the larger New Jersey estuaries of Delaware Bay and Raritan Bay, and other coastal bays from Sandy Hook to Cape May. Forage fishes and juveniles numerically dominate the communities, utilizing the system primarily as a nursery area. Adult marine forms spawn or feed in the bay, but typically inhabit oceanic waters. Warm-water and cool-water migrants appear seasonally, occasionally being present in greater numbers than resident species. Warm-water migrants are more abundant than cool-water migrants, and account for large numbers of fish in the bay from July through November. At this time, young of resident and warm-water migrants coexisting in the estuary reach maximum population sizes. The finfish community, therefore, is characterized by: (1) numerical dominance of a few species; (2) forage fishes and juveniles; (3) seasonal occurrence of warm-water and cool-water migrants; and (4) large fluctuations in the size of populations (Tatham et al., 1984; Vouglitois et al., 1987).

The acid waters of undisturbed Pinelands stream systems support a distinctive fish fauna characterized by thirteen native species and the absence of non-native forms (Hastings 1979, 1984; Graham and Hastings, 1984; Graham, 1993; Zampella and Bunnell, 1998). Native Pinelands fishes include mud sunfish (Acantharchus pomotis), yellow bullhead (Ameiurus natalis), American eel (Anguilla rostrata), pirate perch (Aphredoderus sayanus), blackbanded sunfish (Enneacanthus chaetodon), bluespotted sunfish (Enneacanthus gloriosus), banded sunfish (Enneacanthus obesus), creek chubsucker (Erimyzon oblongus), redfin pickerel (Esox americanus), chain pickerel (Esox niger), swamp darter (Etheostoma fusiforme), tadpole madtom (Noturus gyrinus), and eastern mudminnow (Umbra pygmaea).

Fish species that naturally occur in peripheral areas or that were introduced to New Jersey occur in degraded waters displaying elevated pH and dissolved solids. Peripheral species include pumkinseed (Lepomis gibbosus), brown bullhead (Ameiurus nebulosus), tessellated darter (Etheostoma olmstedi) and golden shiner (Notemigonus crysoleucas). Largemouth bass (Micropterus salmoides) and bluegill (Lepomis macrochirus) are among the most common introduced species. These nonindigenous species usually do not occur in Pinelands waters with pH less than 5.5 (Zampella and Bunnell 1998).

As part of a Pinelands-wide inventory of aquatic communities, Lloyd et al. (1980) described the status of fish communities in freshwater streams within the Barnegat Bay drainage area. This inventory, based on data collected through various surveys, is summarized in Table 8. Although these data reflect past conditions and are too general to assess conditions in individual tributaries, they provide a broad measure of the status of fish communities in the major stream systems discharging to Barnegat Bay.

Lloyd et al. (1980) reported that native, peripheral, and introduced species occurred in the Metedeconk River and the Toms River. The presence of peripheral and introduced species in the Toms River basin indicates that this system is modified in comparison to undisturbed basins. Except for the occurrence of white catfish (Ameirus catus) at one site, fish species reported in Cedar Creek reflect undisturbed conditions. Ten characteristic Pinelands species and two peripheral species were reported for the Oyster Creek and Forked River systems. The two peripheral species were pumpkinseed and golden shiner. Based on two collections, Lloyd et al. (1980) described the Mill Creek system as a modified Pinelands stream. Non-native Pinelands species found in this system included brown bullhead, golden shiner, and pumpkinseed. Collections from Westecunk Creek at Stafford Forge included only characteristic Pinelands species.

The establishment of non-native fish is frequently associated with human-related disturbances (Moyle, 1986). Since elevated pH appears to be a prerequisite for the occurrence of non-native fish species in Pinelands waters (Hastings, 1979, 1984; Graham and Hastings, 1984; Graham, 1993; Zampella and Bunnell, 1998), maintenance of acid-waters is critical for the preservation of the region’s native fauna. Whether a non-native species is able to invade degraded water also depends on accessibility. However, the importance of this factor is somewhat diminished since species such as largemouth bass and bluegill are widely distributed throughout the Pinelands. Because many non-native species are more typical of lakes and ponds (Hastings, 1984), these habitats may be more susceptible than streams to changes in fish communities due to aquatic degradation.

A number of studies have examined the abundance and species composition of decapod crustaceans in Barnegat Bay, particularly in Little Egg Harbor. Previous studies have examined the decapod assemblage in a variety of habitats, such as large and small intertidal creeks, seagrass beds, and macroalgae beds, using a variety of gears, including seines, weirs, trawls, and throw-traps (Wilson et al., 1990a; Sogard and Able, 1991; Rountree and Able, 1993; Szedlmayer and Able, 1996). Viscido et al. (1997) performed a beam trawl survey of the decapod species assemblage on the continental shelf adjacent to Little Egg Inlet. Species found in greatest abundance include, the blue crab (Callinectes sapidus), marsh grass shrimp (Palaemonetes vulgaris), seven-spined bay shrimp (Crangon septemspinosa), the false Zostera shrimp (Hippolyte pleuracanthus), the hermit crab, (Pagurus longicarpus), and green crab (Carcinus maenas). Other species that are less abundant include the rock crab (Cancer irroratus), lady crab (Ovalipes ocellatus), lesser blue crab (Callinectes similis), and spider crabs (Libinia emarginata and L. dubia). Species that are apparently common but either rarely considered or not consistently captured in commonly used collecting gears include mud crabs (e.g., Panopeus herbstii) and fiddler crabs (Uca pugnax, U. minax).

The decapod assemblage in Little Egg Harbor is characterized by both temporal and spatial variation in abundance of decapods. In general, decapod abundances are low in winter, increase through the spring and peak in the summer or fall. This pattern is also found in other mid-Atlantic estuaries (Orth and Heck, 1980; Heck and Thoman, 1984; Heck et al., 1989), as well as in previous studies in Barnegat Bay and adjacent Great Bay (Vouglitois, 1983; Wilson et al., 1990a; Sogard and Able, 1991; Rountree and Able, 1993). However, temporal patterns in decapod abundance can vary among habitats, indicating differential use of habitats. For example, habitat use by decapods is influenced by the presence of refuge against predators (Wilson et al., 1987; Wilson et al., 1990b; Dittel et al., 1995; Hines and Ruiz, 1995), life history pattern (Haefner, 1976; Wilson et al., 1990a; Hines et al., 1995), and physiological state, especially proximity to molting (Hines et al., 1987; Shirley et al., 1990; Metcalf and Lipcius, 1992) or spawning (Schaffner and Diaz, 1988). Temporal patterns in decapod abundance are also affected by physical parameters, such as temperature (Orth and Heck, 1980; Jamieson and Phillips, 1993; Szedlmayer and Able, 1996), and salinity (Heck et al., 1995), and seasonal changes in habitat quality (Orth and Heck, 1980; Butler et al., 1995; Beck, 1997).

There is likewise a considerable amount of temporal and spatial variation in the species composition of decapods. Previous studies have documented several species in each habitat surveyed, including the blue crab (Callinectes sapidus), marsh grass shrimp (Palaemonetes vulgaris), seven-spined bay shrimp (Crangon septemspinosa), the false Zostera shrimp (Hippolyte pleuracanthus), and the rock crab (Cancer irroratus) (Wilson et al., 1990a; Sogard and Able, 1991; Rountree and Able, 1993; Szedlmayer and Able, 1996). Alternatively, there are only a few species localized in one habitat, such as the hermit crab (Pagurus longicarpus) in marsh creeks (Rountree and Able, 1993), and the majority (99.4%) of lady crabs (Ovalipes ocellatus) in deep-water channels (Jivoff and Able, in review). In addition, there are several species present (regardless of habitat) at least one month per season, including the blue crab (Callinectes sapidus), rock crab (Cancer irroratus), lady crab (Ovalipes ocellatus), and spider crabs (Libinia emarginata and L. dubia). This is expected based on their life history mode, and their pattern of using estuarine habitats during all life stages (Bigford, 1979; Millikin and Williams, 1980; Able et al., 1996).

The blue crab (Callinectes sapidus) and hard clam (Mercenaria mercenaria) are currently the only two shellfish species which are of commercial and recreational importance in the Barnegat Bay-Little Egg Harbor estuary. Two other species which were once of commercial or recreational importance include the bay scallop, (Argopecten irradians) and the American oyster, (Crassostrea virginica). They are no longer harvested in the estuary. The blue mussel (Mytilus edulis) and soft-shelled clam (Mya arenaria) also occur in the estuary, but they are neither of recreational nor commercial importance. In the mid-Atlantic region, 7 of the 25 bivalve species found in Barnegat Bay are, or once were, commercially or recreationally important, including the hard clam, soft-shelled clam, bay scallop, American oyster, blue mussel, common razor clam, (Ensis directus), and surf clam (Spisula solidissima) (see Chapter 9).

The Barnegat Bay-Little Egg Harbor estuarine system also provides valuable habitat for shorebirds, seabirds, and waterfowl. The Atlantic coastal corridor of New Jersey is a major migrating pathway for many of these birds. Because of the location of the Barnegat Bay-Little Egg Harbor estuary on the Atlantic Flyway, thousands of shorebirds, seabirds, and waterfowl utilize the estuarine habitat as staging and overwintering areas. State and federal surveys have been conducted on avifauna of the estuary for many years (Castelli et al., 1997; Jenkins, 1997). These surveys are valuable in assessing the occurrence, distribution, migration chronology, and long-term trends of the populations. In addition, other avian investigations (e.g., Burger, 1996, 1997) have detailed the population dynamics and behavior of significant avifauna species utilizing the estuary.

Barnegat Bay supports large and diverse breeding colonies of birds (Burger 1996, 1997). It also provides habitat for one of the most diverse assemblages of colonial-nesting birds in the state. Twenty species of colonial waterbirds nest within Barnegat Bay-Little Egg Harbor estuarine habitats, including ten species of long-legged wading birds, six species of terns, three species of gulls, and black skimmers (Table 9). Colonial waterbirds are avifauna which nest in groups, either comprised exclusively of a single species or, more commonly, several species (Rogers et al., 1990). They include beach nesting birds (e.g., black skimmers and least terns), long-legged wading birds (e.g., herons, egrets, and ibises) which generally require trees and shrubs for nesting, and some gull and tern species which nest on salt marsh islands and dredged spoil islands (U.S. Fish and Wildlife Service, 1996). These avifauna are valuable bioindicators of environmental quality, notably the concentrations of chemical contaminants, levels of human disturbance, resource abundance, and habitat health in the system (Jenkins, 1997). They feed near the top of the food chain on numerous species of fish and invertebrates.

Regular census surveys of shorebirds and seabirds has revealed important long-term changes in population abundance, as well as recent changes associated with the degradation of critical habitat areas. For example, the New Jersey Department of Environmental Protection (Division of Fish, Game and Wildlife) has monitored colonial nesting waterbirds for more than 20 years. In addition, Burger (1997) has conducted comprehensive investigations of colonial waterbird abundance over the same period of time. Declines in population abundance of some species during the past two decades have been attributed to the loss of habitat, increased human disturbance, and predation effects (e.g., from herring gulls and red foxes).

Results of state surveys conducted on colonial waterbird populations in the system between 1977 and 1995 indicate the following (see Tables 10 and 11):

• Among long-legged wading birds, the snowy egret was the only species which showed a significant decline in counts over the survey period;

• No long-legged wading bird species exhibited a long-term increasing trend of abundance;

• Among gulls, terns, and skimmers, the great black-backed gull was the only species which experienced a significant trend of increasing counts;

• Three species of long-legged wading birds (i.e., great egrets, snowy egrets, and glossy ibises) had an increase in the number of active nesting colonies;

• The number of herring gull and great black-backed gull colonies increased, whereas the number of active nesting colonies of black skimmers and least terns significantly decreased over the survey period.

Count trends in abundance of colonial waterbird populations in the Barnegat Bay-Little Egg Harbor estuary generally reflect statewide count trends (Jenkins, 1997).

The most recent comprehensive aerial colonial waterbird surveys were conducted by the New Jersey Department of Environmental Protection in 1989 and 1995. In 1989, 500 long-legged waders were recorded at seven heronies, compared to 435 long-legged waders registered at 14 heronies in 1995. The most abundant species observed for both years combined were, in decreasing order, the snow egret (Egretta thula), little blue heron (E. caerulea), tri-colored heron (E. tricolor), great egret (Casmerodius albus), glossy ibis (Plegadis falcinellus), black-crowned night heron (Nycticorax nycticorax), and yellow-crowned night heron (N. violaceus). Islands used as heronies include Middle Island (highest nesting abundance in 1989), Harvey Sedges (highest nesting abundance in 1995), Flat Island, Chadwick Island, Goosebar Sedge, Story Island, Island Beach, and Barnegat Inlet. More gulls were reported in 1989 (11,000 gulls dominated by laughing gulls, Larus atricilla) than in 1995 (5,000 gulls dominate by herring gulls, L. argentatus). The surveys revealed nearly 5,000 terns in 1989 and 2,600 terns in 1995. Colonies of terns have been documented on several islands in the northern and southern portion of the estuary. Barnegat Bay is an important area for nesting black skimmers (Rynchops niger), which occur on the beaches and bay islands. Barnegat Light is one of the most important sites for nesting black skimmers and least terns (Sterna antillarum).

Although many shorebird species pass through the Barnegat Bay-Little Egg Harbor estuarine marshes and beaches during both spring and fall migrations, the willet (Cataoptrophorus semipalmatus), American oystercatcher (Haematopus palliatus), and piping plover (Charadrius melodus) are the only three nesting species. During the summer months, these three shorebirds inhabit the beaches and dunes of the estuary, with the piping plover exhibiting the narrowest habitat preferences and the willet the broadest. Oystercatchers and willets also frequent broad sandy flats, marsh islands, and dredged material islands (Terres, 1980; Nol and Humphrey, 1994; Kibbe, 1995). Willets can be found in virtually any higher portions of the open marsh. Piping plovers and most willets leave the area of the Barnegat Bay estuary in early autumn to winter along the southeast Atlantic, Gulf of Mexico and Caribbean coasts (Haig, 1992; Nol and Humphrey, 1994; Kibbe, 1995; USFWS, 1996). While a majority of oystercatchers probably also leave the estuary in the fall, a sizable number remain along the southern New Jersey coast through the winter months, frequently overwintering in the southern portion of the estuary.

During late March and early April, all three species arrive in the area to begin nesting -- oystercatchers being the first to arrive, and willets the last (Haig, 1992; Nol and Humphrey, 1994). Willets prefer to nest along dunes covered by thick grasses and along the marsh-upland edge and other higher areas on the marsh and marsh islands (Terres, 1980; Kibbe, 1995). Along the marsh-upland edges, they select areas under dense brush, avoiding the open situations preferred by piping plovers and American oystercatchers. Burger and Shisler (1978) noted that willets often nest on low spoil piles associated with mosquito ditching and other open marsh water management practices. Nests range from shallow depressions in the sand to dense cups formed of marsh or dune vegetation (Kibbe, 1995). American oystercatchers, while inhabiting some of the same general areas as willets, tend to nest in much more open situations, such as broad sand flats, open beaches, sparsely vegetated dredge spoil, and sandy portions of marsh islands (Nol and Humphrey, 1994). The oystercatcher’s nesting substrate is typically sand or shell fragments, but can include wrack on marsh islands. In contrast to the broader nesting habitat of both willets and oystercatchers, piping plovers in the estuary currently nest only on barrier island beaches, although they have occasionally nested on sandy dredge disposal sites (Haig, 1992; USFWS, 1996). Plovers usually nest in small shallow, shell-lined depressions on open sandy beaches, either along broad sand flats or on the upper beach berm (Haig, 1992). Less commonly, nests are located within the dune system, usually in overwash or blowout areas. Piping plovers locate their nests in totally exposed locations or sheltered areas at the base of a clump of beach grass (Ammophila breviligulata) or other beach vegetation.

Willets feed on a variety of marine invertebrates including marine worms, crustaceans, and mollusks as well as on insects found along the muddy banks of tidal creeks, mud flats, sand flats, and salt marsh ponds and panes (Kibbe, 1995). Oystercatchers consume marine mollusks, especially bivalves, but also ingest other marine invertebrates captured on mudflats, tidal washes, and on exposed marsh surfaces (Nol and Humphrey, 1994). Piping plovers feed on smaller marine invertebrates, including marine worms and crustaceans, as well as terrestrial insects, larvae and eggs captured in high wet sandy areas, at the wrack line and on the upper dry beach (Haig, 1992).

The recently completed New Jersey Breeding Bird Atlas project (New Jersey Audubon Society, in preparation) found that American oystercatchers and willets were "possible," "probable," or "confirmed" breeding in 12 and 25 survey blocks, respectively, within the Barnegat Bay-Little Egg Harbor estuary (a survey block = ~9.5 square miles). No trend data specific to the estuary or state are available for either the oystercatcher or willet. North American Breeding Bird Survey (BBS) routes do not adequately sample large roadless areas such as salt marsh habitat and sample sizes and are not sufficient to evaluate local trends. On a broader scale, the BBS data suggest that willet populations were roughly stable in the U.S. Fish and Wildlife Service (FWS) Region 5 (roughly the northeastern U.S., including New Jersey) between 1966-1996. BBS data were not available for American oystercatchers; however, the population is generally believed to be expanding (Nol and Humphrey 1994). Only the American oystercatcher is regularly observed on Christmas bird counts and then only in the extreme southern portion of the estuary. Numbers counted on the Oceanville count have been generally increasing over the past 15 years.

Because they are listed as "threatened" under the federal Endangered Species Act and as "endangered" by the New Jersey Department of Environmental Protection, piping plovers populations are closely monitored. In the Barnegat Bay-Little Egg Harbor estuary area, piping plovers have nested at the following sites over the past 10 years: Mantoloking, South Mantoloking beach (Brick Twp.), Island Beach State Park, Barnegat Light, Loveladies, and the Holgate section of Forsythe National Wildlife Refuge (Table 12). Populations generally increased during the period from 1985 to 1992, peaking at 37 nesting pairs (Jenkins et al., 1998a). Since that time populations have declined markedly to the lowest levels (17 pairs in 1997) observed since intensive monitoring began in 1985.

The habitat for all three species has been significantly diminished or altered by beach stabilization, particularly at inlets, through the construction of jetties. Residential and commercial development has also been detrimental. Currently, however, the primary threats in the Barnegat Bay-Little Egg Harbor estuary region involve excessive predation and disturbance of nesting by humans, dogs, and vehicles (Jenkins et al., 1998b). This is especially true for the piping plover, with its habitat restricted to the more heavily developed and more highly disturbed barrier island beaches. Disturbance disrupts normal incubation and brood care, leading to increased nest and chick mortality from exposure and predation (Haig, 1992; USFWS, 1996). Humans also cause direct mortality by accidentally crushing cryptic nests and chicks. Vehicles operating on the beach pose a particular threat in this regard.

The most significant predators on these shorebirds in the Barnegat Bay-Little Egg Harbor estuary include red foxes (Vulpes vulpes), raccoons (Procyon lotor), gulls (Larus spp.) and crows (Corvus spp.) (Jenkins et al., 1998b). The populations of all of these predators have increased during the past few decades as these animals have adapted to anthropogenic changes in the estuary.

The piping plover is the only breeding shorebird for which there is an active management program in the estuary region. Because of their overlapping nesting habitats, American oystercatchers receive some benefit from these management efforts. Management is primarily directed at two areas: (1) reducing the direct and indirect impacts of human recreation; and (2) reducing losses of nests and chicks to predators.

Reducing the affects of human disturbance typically involves the construction of fencing and posting signs around nesting areas (Jenkins et al., 1998b). In historically used nesting areas, such as the northern end of Barnegat Light, fencing is erected prior to the nesting season. In other areas, "symbolic" string and post fencing are erected after individual nests have been established. At Holgate, which is part of the Forsythe National Wildlife Refuge, human disturbance is virtually eliminated by closing the beach to human access during the nesting season. Educational outreach designed to inform the beach-going public of the presence of beach-nesting shorebirds is a very important aspect of managing human disturbance.

The most common method employed to reduce predation of nests is the use of predator exclosures. Predator exclosures consist of a small circular fence (~3 m) topped with netting or twine placed over the nest. They are designed to allow normal ingress and egress by incubating birds while excluding most predators (USFWS, 1996). The limited success of predator exclosures and their inability to protect precocial chicks has led wildlife managers to consider the employment of other methods, including the removal of predators and control of predator populations by trapping, shooting, and poisoning.

In addition to shorebirds and colonial nesting birds, Barnegat Bay’s marshes and islands are also home to the secretive clapper rail (Rallus longirostris crepitans). The clapper rail is a large gray-feathered salt marsh bird (4-5 cm high) commonly found nesting on any tributary of an estuary where marsh cordgrass (Spartina alterniflora) and fiddler crabs (Uca spp.) occur in association (Sanderson, 1977). It's calls can be heard on the tidal marshes from April through December in response to a sudden loud noise. While their primary food tends to be fiddler crabs, these birds are opportunistic feeders and will also consume marsh snails (Melampus bidentatus), grasshoppers, and other easily captured prey. The clapper rail is considered a common marsh nester from Little Egg Harbor north to the Barnegat Inlet. Farther north of the inlet, however, its numbers decrease as the tall marsh cordgrass it nests in also declines in abundance. The areal coverage of the salt marsh has been greatly reduced by residential fill. While always common, the population has declined over the centuries as marshes have been filled, diked or in other ways removed from tidal flow.

Some clapper rails can be found in the Barnegat Bay-Little Egg Harbor estuary throughout the winter; however, the local nesters arrive in the estuary as early as mid-March, with most appearing by mid-April. Nesting begins during the last week of May, and the peak of the first hatch occurs around the third week of June. The nest is usually located along tidal creeks or ditches where the tall cordgrass is found in linear bands at least 2 m wide, and the falling tide exposes adjacent mud flats for feeding. Only a few nests are found among high tide bush (Iva frutescens) and salt hay (Spartina patens) when these higher habitats occur adjacent to suitable feeding areas. In all cases a grass bowl 2-4 cm in diameter is constructed high enough to prevent daily flooding by tides. Some of the nests have a ramp built from the marsh floor to the bowl, and often a canopy of surrounding vegetation is pulled over the nest to provide overhead cover and protection from predators (Bent,1963). Nesting is usually completed by the end of July, and birds may start migrating south as early as the last week of August. Bandings indicate that the birds overwinter from South Carolina to Florida.

As with most animal populations, the major limiting factor for the clapper rail is adequate habitat. During the last fifty years of this century, almost 30% of the estuary marshes have been lost to dredging and filling (Ferrigno et al, 1973). However, clapper rail population numbers continually fluctuate in response to storms, high tides, and habitat changes associated with rainfall (Ferrigno and Kosinski, 1969). Other factors such as harsh winters, high predation, and human disturbance simply accentuate the trends. During the nesting season, storm tides and lunar tides often lead to the destruction of nests. Predators such as hawks and owls will take the young and adults, while fox, raccoons, gulls, and crows prey upon the eggs and fledglings. In years of low rainfall during the spring, growth of the marsh grasses is stunted. This renders the nests more vulnerable to predators and results in lower nest success and possibly lower survival of young (Ferrigno and Kosinski, 1969). Hurricanes have caused extensive losses of young and adults as well as nests due to high winds and storm surge (Shoemaker and Widjeskog, 1977). While this is an unusual occurrence in the Barnegat Bay area, the resulting reduction in population abundance can persist for years.

In past years, there was concern for clapper rail population loss due to the use of pesticides (i.e., DDT and malathion) on the marshes to control mosquito production. Pesticide spraying appears to have reduced the fiddler crab population which is heavily used by the clapper rail (Ferrigno and Kosinski, 1969). Changes in mosquito control practices have greatly reduced the use of pesticides, thereby mitigating their impact on clappers in the bay today.

Hunting of this bird continues on a very limited scale in New Jersey. There is no indication that hunting has had a limiting effect upon the rail population in the Barnegat Bay-Little Egg Harbor area. The average bag taken annually by hunters is not known, but it is unlikely to be more than 3,000 clapper rails statewide. Within the estuary, harvest and hunter pressure is highest in the Little Egg Harbor area near the Seven Bridges Road that separates Great Bay from the Barnegat Bay-Little Egg Harbor system. There appears to be less and less hunting pressure upon this bird, and this trend is expected to continue.

Human disturbance during the breeding and nesting cycle may be important. Continual boat traffic and jet skiing in small creeks, as well as extensive fishing and crabbing from the shore, have the potential to reduce nesting success and brood survival. Wakes from speeding watercraft, which break onto the marsh, disturb the birds and destroy their nests. Destruction of grass under foot reduces the area suitable for nesting birds. Long-term management of this species in the Barnegat Bay-Little Egg Harbor estuary can best be accomplished by protecting the marsh from destruction and degradation by humans. Disturbance during the breeding and nesting period may be an important factor in reducing nesting success and brood survival.

Shorebirds travel great distances between wintering grounds in South America and breeding grounds in the Arctic. They fuel these long flights by feeding heavily in a few areas (known as stopovers), where food is extremely abundant. This results in concentrations of shorebirds along the route, such as at Delaware Bay, the largest springtime stopover in the continental U.S. Their springtime migration is extremely time-limited: shorebirds make the journey and arrive in the Arctic just after snow-melt, and immediately begin nest initiation and egg-laying. They must arrive in good condition, since food is very limited and females lay four eggs that amount to 60% of body mass. Concentrating at stopovers is necessary, especially in spring before invertebrate prey is very abundant, but this activity makes the birds vulnerable to catastrophic events like oil spills. In Delaware Bay, the principal food for shorebirds is horseshoe crab eggs, made available by the high density of horseshoe crabs that spawn in May. In Barnegat Bay, shorebirds feed on invertebrates in marsh mudflats and beaches. In spring (April through mid-June), the most abundant species in the region are sanderling (Calidris alba), semipalmated plover (Charadrius semipalmatus), dunlin (Calidris alpina), short-billed dowitcher (Limnodromus griseus), red knot (Calidris canutus), ruddy turnstone (Arenaria interpres), and semipalmated sandpiper (Calidris pusilla). In the fall migration (mid-July through September), the same species occur, but may vary in abundance. Semipalmated sandpipers, for example, tend to concentrate in the Bay of Fundy, and spend less time in New Jersey on their southbound flight.

Shorebirds have affinities for particular types of habitat. Sanderling, red knot and ruddy turnstone prefer sandy beaches for feeding; they may also be found on shallow impoundments, but are usually in the marsh only for roosting or resting. Semipalmated sandpiper, dunlin, and dowitcher prefer mudflats and shallow impoundments for foraging, but may occasionally be seen on beaches. Semipalmated plovers prefer beaches but are found in fair numbers in marsh habitats.

Biologists from the Endangered and Nongame Species Program have conducted annual surveys of shorebirds on Delaware Bay beaches since 1986. The trend in total shorebirds has remained fairly stable, but significant declines have been documented in semipalmated sandpipers and sanderlings. There is also some concern over numbers of red knots, for which the lowest count recorded was in 1996. The red knot was listed as a state threatened species in 1999. Declining trends also have been observed in the region and the Western Hemisphere.

Disturbance is one of the major problems facing migratory shorebirds. The cost of migration can be great, even when food is abundant and weather conditions are good. Spring migrants must feed nearly constantly to gain the weight necessary for their journey and to prepare them for nesting. Human presence, especially beach-walkers, unleashed dogs, and vehicles will disrupt the birds and cause them to leave optimal feeding beaches. When shorebirds constantly fly away from feeding areas due to disturbance, they cannot obtain sufficient energy for long migrations.

Since disturbance is one of the major threats to shorebirds, human activities should be managed to reduce intrusion into foraging and roosting areas. This can be done by establishing viewing areas marked with educational signs. Such an effort is most important during the spring migration in areas where shorebirds concentrate. In addition, marsh habitats where water control is available can be managed to provide shallow-water mudflat or impoundment habitat. In this case, water levels should be manipulated to provide shallow-water or moist-soil habitat during the spring and fall migration periods.

The Barnegat Bay-Little Egg Harbor estuarine system is also an important staging area and overwintering area for seabird populations. Cormorants (Phalacrocorax spp.), scoters (Melanitta spp.), loons (Gavia spp.), northern gannet (Sula bassanus), sooty shearwater (Puffinus griseus), and Wilson's storm petrel (Oceanites oceanicus) are examples of seabird populations migrating through the area. Surveys conducted from July through December 1995 in Cape May County registered more than 900,000 seabirds migrating along the coast (U.S. Fish and Wildlife Service, 1996).

Barnegat Bay is an important migration and wintering habitat for waterfowl. Since 1956, the New Jersey Division of Fish, Game and Wildlife has conducted standardized aerial waterfowl surveys along the coastal wetlands of New Jersey, including the Barnegat Bay-Little Egg Harbor study area. The U.S. Fish and Wildlife Service also conducted waterfowl surveys on portions of the study area from 1985-1993. These surveys have been useful in documenting the occurrence, distribution, migration chronology, and long-term trends of waterfowl populations. New Jersey Division of Fish, Game and Wildlife aerial surveys were flown each January over the 40-year period. Between 1965 and 1972, state aerial surveys were also flown monthly from September through December (Castelli et al., 1997). These long-term aerial surveys clearly indicate that the Barnegat Bay-Little Egg Harbor system provides important migration and wintering habitat for waterfowl.

State surveys have revealed the occurrence of 22 waterfowl species and 3 groups of species (species of merganser, scaup, and scoter), and federal surveys documented 20 species and 3 goups of species (same as above) in the Barnegat Bay-Little Egg Harbor estuary study area (Table 14). Frequently observed waterfowl species were American black ducks (Anas rubripes) and mallards (Anas platyrhynchos) which were recorded during every survey. Atlantic brant (Branta bernicla), Canada goose (Branta canadensis), bufflehead (Bucephala albeola), common goldeneye (Bucephala clangula), canvasback (Aythya valisineria), scaup (Aythya marila and Aytha affinis), American widgeon (Anas americana), green-winged teal (Anas crecca), merganser spp. (Mergus serrator, M. merganser, and Lophodytes cucullatus), mute swans (Cygnus olor), and oldsquaw (Clangula hyemalis) were other commonly observed species.

Species present during September are largely resident breeders and a few early migrants. Species diversity peaks during fall migration and remains generally high throughout the winter. Waterfowl abundance appears to be maximum during the winter months (Castelli et al., 1997). Aerial surveys conducted in November show an average of more than 25,000 waterfowl migrating through the study area. The declining order of abundance of waterfowl species at this time was as follows: brant, American black duck, scaup, mallard, bufflehead, Canada goose, and mergansers. Aerial waterfowl counts during mid-winter surveys average nearly 50,000 birds, including significant concentrations, in descending order, of greater and lesser scaup (Aythya marila and Aythya affinis), brant (Branta bernicla), American black duck (Anas rubripes), bufflehead (Bucephala albeola), canvasback (Aythya valisineria), mallard (Anas platyrhynchos), Canada goose (Branta canadensis), common goldeneye (Bucephala clangula), mergansers (Mergus spp.), and oldsquaw (Clangula hyemalis). In mid-winter surveys, migratory populations of sea ducks (e.g., canvasback, common goldeneye, and scaup) occur in significant concentrations (U.S. Fish and Wildlife and Service, 1996).

Analysis of the long-term waterfowl survey data for Barnegat Bay by Castelli et al., (1997) show that some species, notably mallard, northern pintail, Canada goose and oldsquaws displayed significant positive trends in population numbers. Scaup and redheads were identified as having significant negative trends.

Waterfowl concentration areas, as determined by aerial survey methods, vary widely by species, season, and weather conditions, making it difficult to identify "critical habitat areas". Individual species and multi-species flocks are widely scattered within individual flight survey segments; the location of waterfowl on specific habitats is not routinely recorded. During periods of severe weather with snow and extensive ice cover, waterfowl may also alter their behavior, concentrating in inlets and other open water areas. Standard aerial surveys provide only a diurnal snapshot of the distribution of waterfowl, often during the periods when some species are comparatively inactive (i.e., loafing in rafted concentrations). In addition, many waterfowl are crepuscular or nocturnal feeders and little is known about the location of important feeding areas. Some correlation can be drawn between aerial surveys, habitat, and food preferences (U.S. Fish and Wildlife Service, 1996). Castelli et al. (1997) found that dabbling ducks tend to dominate in areas where salt marsh habitat prevails. As might be expected, diving ducks dominate in open water areas. Swans were found primarily in areas of extensive beds of brackish water submerged aquatic vegetation, their preferred food source. However due to the incomplete knowledge of the habitat requirements of winter waterfowl, the identification of critical habitat areas is problematic. Future research must delineate more effectively the critical feeding habitats and concentration areas by employing telemetry and time activity budget studies (Castelli et al., 1997).

The Barnegat Bay-Little Egg Harbor estuary is an important waterfowl hunting area (Nichols and Castelli, 1997). Between 1961 and 1995, the total waterfowl harvest peaked during the 1971-80 period and declined thereafter (Figure 4). Black ducks, mallards, and buffleheads comprised the bulk of the harvest during this period, accounting for 20%, 14%, and 12% of the total harvest (Figure 5). Waterfowl have considerable economic and recreational value to the area.

Osprey, peregrine falcon, and northern harrier are the primary raptors in this estuarine system. Ospreys are highly migratory; most winter in South America, with some birds remaining in the southeastern U.S. Peregrine falcons that nest in New Jersey are mostly non-migratory, and remain in their nesting areas year around. Peregrines from northern nesting grounds migrate through and may winter in the state. Harriers are found in New Jersey marshes year around; New Jersey nesters probably also winter here, joined by many migrants from northern areas. All three species are on the New Jersey State endangered species list: the osprey is state threatened, the peregrine is state and federally endangered, and the harrier is state endangered.

These three species, all high trophic-level feeders, consume very different prey. Ospreys are primarily fish-eaters, taking ocean and bay fish such as white perch, menhaden and flounder. Peregrine falcons are bird-eaters that take their prey in flight. They feed on both local and migratory birds such as shorebirds, blue jays, flickers, and occasionally small ducks and gulls. Harriers hunt the marsh for rodents and small birds, in their characteristic low, "quartering" manner with a slight v-shaped profile.

Ospreys return to New Jersey in late March and begin building large stick nests on man-made nest platforms, duck blinds, channel markers, as well as on the ground. Three or four eggs are laid in mid- to late April, and incubation takes 35 days. Young are altricial, and fledge the nest at about 8 weeks of age, in mid- to late July. They begin migrating south in late August. Peregrine falcons begin nesting in mid-March. They nest on man-made coastal towers installed in the early 1980's to support the reintroduced population, as well as on large bridges and some buildings. They lay 3 or 4 eggs in a "scrape," a shallow depression in gravel; eggs hatch in about 32 days. Young fledge in 6 to 7 weeks, but remain in the area of the nest until they are able to fly and catch food. Harriers nest on the ground in the marsh, usually in Spartina and higher vegetation that keeps the nest above tidal water. They lay 4 or 5 eggs in early April, but may be delayed by spring flood tides. Young fledge in July. Timing and nest success is highly dependent on rodent populations and tides. During seasons when food is limited, the number of young that fledge is usually reduced.

Ospreys have increased statewide from 50 nests in 1975 to over 250 nests in 1998. Barnegat Bay has always been an important nesting area due to the density of nests and the excellent habitat. In 1997 and 1998, nest success was reduced in most colonies along the Atlantic coast, apparently resulting in starvation in some nestlings. The peregrine falcon population has been stable since 1992, with nest success in the estuary usually above average. Northern harriers have also been relatively stable, but it is normal for this species to have variable nest success year to year, depending on tidal conditions and prey populations. Available data suggest that the estuary nesting population is relatively low. Most nests occur in the Delaware Bay marshes.

These three aforementioned species are limited to varying degrees by human disturbance: all will abandon nesting when humans intrude nesting areas. Harriers and peregrines are particularly sensitive to disturbance. Ospreys in New Jersey are limited by the availability of trees and other structures for nesting, as a result of the reduction of natural habitats associated with development on barrier islands Predation can limit osprey and harrier nest success where predator populations are high. Toxins affect ospreys and peregrines. These birds are relatively long lived and bioconcentrate contaminants from their prey. Monitoring to date has not revealed significant toxic residues in Atlantic ospreys, but peregrines may have relatively high levels of PCBs and other organochlorines.

The greatest threat to these species is human disturbance. As a consequence, it is necessary to protect nest sites from disturbance throughout the nesting season. This can be accomplished by sign posting and enforcement of protection areas. Ospreys and peregrines require maintenance of nest structures. In the case of ospreys, placing nest platforms in suitable habitat has helped the population grow.

1. Estuarine (Marsh) Associated Birds

In contrast to the large long-legged wading birds, flocking shorebirds and waterfowl, and the raucous ubiquitous gulls, songbirds are relatively inconspicuous inhabitants of the Barnegat Bay-Little Egg Harbor estuarine marshes. Three species, more often heard than seen, characterize the emergent Spartina marshes and the adjacent brackish and freshwater marshes. These are seaside sparrow (Ammodramus maritimus), the sharp-tailed sparrow (Ammodramus caudacutus), and the marsh wren (Cistothorus palustris). Both sparrows breed in the saltmea