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The restoration of impoundments in the West PooI by installing water control structures and subdividing it into two smaller units. The goal is to improve water quality, restore wetland vegetation and habitat diversity, ensure future water supply, and reduce potential disease problems. The document also mentions the use of marine water to flood the impoundment and increase soil salinity for brackish water vegetation.
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DRAFT
Environmental Assessment
Inpoundment Rehabil^ itation
Edwin B. Forsythe National Wild1ife^ Refuge Brigantine Division
Prepared By:
U.S. Fish and^ Wildlife^ Senrice
U.S. Department of the Interior Edwin B. Forsythe National^ Wild1ife^ Refuge Oceanville, New^ JerseY December l-99L
on
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II.
III.
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Environmental Assessment
hrrpose and Need for Action
Alternatives
Affected Environment
A. Physical (^) Considerations Clinate Air (^) Quality Soils/Topography Ge,oloqy/Hydrology Surface/Tida1 Water
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B. (^) Biological Resources L. Vegetation
C. Socio (^) - Economic
Environmental (^) Conseguences
A. Physical Resources
B. Biological Resources a. Vegetation b. wildlife i. Threatened and Endangered Species ii. Waterfowl and other Waterbirds iii. Marnmals iv. Reptiles and Amphibians v. Fisheries
C. Socio (^) - Economic^22
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I PURPOSE AIID ITEED (^) FOR ACTION
The U.S. Fish and Wildlife (^) Service proposes to rehabilitate the existing (^) wetland impoundments at the Brigantine Division of the Edwin B. Forsythe National Wildlife Refuge (NWR) (Appendix (^) 1). The purpose (^) of this rehabilitation is to restore the declining wetland ecosystem by increasing management capabilities in the existing impoundments. Restoration of the impoundments will be accomplished by installing water control structures and subdividing the West PooI into two smaller units. This will enable the use of management techniques to improve water guality,^ restore wetland vegetation and habitat diversity, ensure future water (^) supply with improved distribution capabilities throughout the impoundments, and reduce potential^ disease problems.
The need for this rehabilitation is in conjunction with the mission of the National Wildlife Refuge System; the North American Waterfowl Management PIan, dD agreement by several Federal and State agencies, Canada and the private sector to conserve, restore, and enhance wetlands and waterfowl habitat; and (^) Forsythe NWR objectives. A U.S. Fish and Wildlife Service (Serrrice) (^) Region 5 policy was issued on April 5, L991 which clearly guides the Service on acceptable management/restoration activities in wetland ecosystems (Appendix (^) 2). These guidelines (^) support efforts to restore poorly funct,ioning wetland ecosystems and discourage intensive (^) manipulation of (^) healthy wetland systems. The proposed (^) Brigantine impoundment project satisfies the criteria outlined in the policy.
In 1986, (^) the United States ratified the United Nations trConvention (^) on Wetlands of International Importance especially as Waterfowl Habitatrr, commonly known as the Ramsar Convention. Forsythe Refuge was one of four wetlands in the U.S. to receive recogtnition as a wetland of international importance when the Ramsar Convention was ratified. Currently, the refuge irnpoundments cannot be managed to their (^) maximum capabilities.
The impoundments were established in the early L950s by construction of a dike system in the coastal saltmarsh around the mouth of Doughty Creek. The total impounded area managed by the Fish and Wildlife Selrrice is 590 ha. and includes Lily Lake, Doughty Creek, West, Experimental, and East Pools. The l{illian Vogt Pool, commonly known as the West (^) Pool, is 329 ha. and is managed mainly as a freshwater impoundment (less^ than 8 ppt salinity). The^ East Pool^ is 2L7 ha. and is managed as a brackish impoundment (l-0-30^ ppt salinity). Freshwater sources for the West Pool occur^ from drainage from Doughty Creek, precipitation and upland
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runoff. Excess (^) water from the West PooI and precipitation are the sources (^) of freshwater for the East Pool. Tidal water from (^) the ad introduced (^) into e structures.
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acent bays, channels and ditches may be ther impoundment via water control
The experimental pool is a small impoundment at the western end of the West (^) Pool. In times of adeqr-rate water supply, the experimental pool provides good (^) brood and feeding habitat for waterfowl in its current state. Wading birds and (^) shorebirds also use the area. When it was created, dikes were built and a water retention control structure was installed to ut,ilize the inpoundment as a moist soil unit. Through experinentation it was discovered that the water level of the L9-acre pool^ could not be adeguately controlled. Upland runoff, internal springs, and possible leakage through the dike bed prevented drying the pool for moist soil plant growth. The project was (^) abandoned and the water control structure is now (^) deteriorated. Replacement of the structure would allow a dependable water supply in the pool (^) even though it will never be managed as a moist soil unit.
Two water-control structures (culverts with riser boards) provide (^) the only water-Ievel control in the West (^) Pool (Appendix (^) 1). One structure is located on (^) the south dike, adjacent to tidal saltmarsh (WCS (^) #10), and the other structure is (^) located on the crossdike (WCS (^) #6), adjacent to the East Pool. (^) Freshwater enters into the East Pool through WCS (^) #0 on the crossdike. One tidal flapgate structure on the east dike (^) allows saltwater entry into the East Pool (WCS #3). Water^ control structure (^) #Z is no longer functioning and needs (^) to be replaced.
The two l{est PooI structures are ineffective for the amount of water (812^ ac. (^) ) needed to be nanaged. An attempt to completely drawdown the West (^) Pool occurred in August, L990, through the south dike water-control structure. (^) This was the first attempt to drain the impoundment since 1969. The drawdown (^) began on Augrust 27, 1,990, and took approximately ten days for water levels to drop a foot, resulting in 30? of the (^) mudflats exposed in the pool. (^) The crossdike structure was opened to speed (^) the draining process but boards had to be replaced because (^) saltwater started entering the West Pool (^) through this (^) structure after water 1eve1s had dropped in the l{est Pool. By the end of September, the outer perimeter (^) of the pool (^) dried out enough to walk on without sinking. The center of the pool (^) and the northeast and northwest corners never dried out. The boards were
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For decades freshwater has been held in the^ West^ PooI^ to provide (^) habitat diversity for waterfowl, shorebirds, (^) and wading birds. The pool is managed to provide^ resting and feeding habitat for birds in the faII and^ spring^ nigrations and critical wintering habitat. During the^ summer,^ the pool provides (^) brood habitat for waterfowl. Over the years the forces of^ wind/rrave action, erosion, eutrophication^ and siltation have seriously^ degraded^ the quality^ of^ the habitat. Shallow, stagnant^ water^ within the^ pool^ prevents drying of the unconsolidated muck on^ the^ pool^ bottom,^ and poses (^) a bacterial hazard to birds in the sulDmer months. Definable water channels such as Doughty Creek and former tidal ditches were virtually eliminated and the^ perimeter ditches nearly filled in with silt. The drainage routes have been so altered that they lrere completely ineffective before rehabilitation began in l-989.
The East PooI is managed to provide waterfowl^ breeding^ pair, nesting and brood-rearing habitat. The East Pool has not been adequately managed because of the lack of^ functional water-control structures and the linited^ number^ of structures. The structures in place^ now are not^ capable^ of flushing the pool^ with tidal water. one of the structures has had serious leaks since the 1960s with many attempts to repair the problems. This has resulted in a reduction in management capability. Years of siltation and biomass accumulation have reduced water circulation and thus water quality in this pool as well. Before rehabilitation began in the East PooI, original tidal creeks and mosguito ditches had fi1led in and severely linited water management capabilities. The results have been high salinities, loss of vegetation through stagnation and snow goose^ eat-outs, and general^ habitat degradation.
Rehabilitation began in^1988 in the^ East Pool^ and^1989 in the West PooI to dredge existing creeks and^ perimeter^ and drainage ditches and create petmanent^ water^ areas.^ This work was accornplished with the use of an anphibious tractor with rotary ditcher and a channel ditcher called a^ cookie cutter. The work has been successful in inproving water circulation in both impoundments; however, the ditches are already filling with sediment, which will result in repeated ditching every 3 to 5 years,^ unless water flowage across the pools is achieved. Even with ditching, all management needs cannot be achieved such as adequate water supply,^ habitat diversity, and energency drawdowns for disease control.
The (^) refuge has a significant problem with a nuisance species, Phraqmites, within the^ inpoundment^ system. Phragmites, a giant^ reed grass, is a plant that^ displaces the more desirable plants, but has little^ value^ as^ wildlife food or cover. The addition of water-control structures in
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the impoundments would^ help^ control the^ spread^ of Phragrmites. Siltation and eutrophication have^ decreased^ the original water depth and changed vegetation^ dominance^ in^ the West PooI with Phragmites being the current dominant^ cover on the higher itislandsrr.^ If not for the extensive^ lower elevations within the pool,^ Phragrmites would^ probably^ be much more widespread. In the^ West^ Pool, out of^ a^ total^44 vegetatj-on transect stations surrreyed in^1980 that^ were^ not covered by water, L6 stations (358)^ exhibited a^ near^ total dominance by Phracrmites; while an additional six^ stations vrere experiencing Phragrnites intrusions of various intensities, which did not constitute dominance.
Phracrmites has declined in total percent cover^ from^ 26. percent (^) in L985 to LO.2 percent (^) in 1991. Phracrmites was recorded in 19 plots out of 7L (272)^ in L985.^ Five additional plots^ were in areas where Phracmites^ had^ been dominant but was not present^ due to^ chemical^ control in^ L984. and a prescribed burn in L985. In^ 1991,^ P[4g-ites. was observed in L7 out of L3.L plots^ (152).^ The^ freguency^ of occurrence cannot be statistically compared between^ the^ two surveys due to the differences in number of plots^ and locations; however, it is probable^ that the^ periodic chemical and burning management have decreased Phragrmites^ on some of the islands, resulting in the decrease in total percent (^) cover.
In the East PooI, many of the islands have^ become^ dominated by Phraqmites replacing vegetation such^ as^ Spartina^ patens. Vegetation transects perfotmed^ in 1990 in the^ East^ Pool revealed Phragmites has doubled in percent cover^ and^ had^ a 25 percent^ increase in frequency of^ occurrence from^ L989, which indicates this species is rapidly expanding^ through the East Pool.
Pore water salinity and surface water salinity were compared between 1989 and 1990 in the^ East^ Pool.^ Both^ soil^ and surface water salinities showed^ significant^ reductions.^ The use of marine water to flood the impoundment^ and increase the soil salinity to favor brackish water^ vegetation^ on^ the nesting islands is needed; however, the^ water^ control structures currently in the pool^ do^ not^ have^ this capability.
The threat of botulisn in the pools^ is^ always^ a^ concern^ each sunmer. Shallow water permits^ rapid watming^ of^ the submerged marsh soil during periods^ of^ high^ temperatures. Toxin is produced^ when these soils contain both^ the^ spores of C. botulinum and suitable organic nutrients for^ spore gemination and reproduction of bacterial cells.^ Because the pools are so large and have linited water-control capability, rapid flooding or draining^ cannot^ be
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West Pool
The West (^) Pool would (^) be subdivided with an earthen dike beginning at the southern tip of the (^) experimental pool and running straight across Doughty (^) Creek tying into the high ground near the obsenration tower (^) at the eastern end of the west dike, for a total (^) distance of about L,57O feet. The dike will be 10 feet wide with (^) a. 1 to 3 slope and approximately 5-L/2 feet high. This dike is needed to allow water to enter directly from Doughty Creek into either side of the proposed crossdike. Without this snall dike, one half of the West Pool would (^) not be capable of (^) being drained, thus liniting (^) rehabilitation success. Two water-control structures (WCS (^) #LL and WCS (^) #L2), each providing for lO-foot-wide (^) stop logs and a 48-inch-diameter smooth pipe, would be placed (^) in the dike. The approximate distances are 872' and (^) 942' from the experimental pool station. The inverts of the pipe would be a -1.0 for the upstream end down to -L.2 at the downstream end. The total length of each pipe would (^) be 45 feet. Each pipe would (^) lead into a separate unit of the West Poo1.
A second proposed^ crossdike would begin at about 9L0' from the experimental pool station on the new dike and split the West PooI into two (2)^ approximately equal pools (^) teminating near the peregrine (^) nest platform located on the existing crossdike between the West and East (^) Pools. This is a distance of about 7L55 feet. The (^) crossdike would be built to a uniform top elevation of 4.5 feet (above (^) mean sea level) to allow for shrinkage and settling. The top width will be 8 feet wide and the sides of the dike will have a L to 3 slope. The proposed work wiII be accomplished entirely within the existing impounded system which will elininate all runoff into the adjacent saltnarsh, thereby (^) nininizing adverse effects.
Three additional water-control structures consisting of culverts (aluminun) (^) fitted with flap gates (^) and riser boards (^) will be installed in the West Pool. A structure (WCS (^) #7) will be added in the east end of the new subimpoundment (^) dike to allow water exchange between the two (^) new units (35 (^) inch diameter culvert). A structure (WCS (^) #9) wiII be installed on the north dike to allow tidal (^) exchange into the West Pool's north unit. This structure vould only be used to bring saltwater into the freshwater north unit in an emergency situation such as a disease outbreak. A structure (WCS (^) #8) will
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be installed on the (^) East/WesE PooI crossdike to allow water exchange between the West Pool,s (^) north unit and the East Pool.
East PooI
Three water-control structures wiII be installed in the East Poo1. (^) Two tidal-trunk-gates will be located on the (^) northwest and southwest corners of the East Pool (wCS (^) #a and (^) #5). One tidal-trunk-gate (wcs (^) #1) will be installed (^) on the southeast corner to replace structure #2. These^ structures^ were designed and^ are^ currently used (^) by the Delaware Division of Fish and Wildlife. They were patterned^ after the wooden rice trunk gates used (^) in the south to grow (^) rice by manipulating water levels.
The tidal-trunk-gates are constructed entirely of marine aluninum, instead of wood. Each structure will consist of a 36-inch dianeter corrugated culvert attached on the saltmarsh side to a concave aluminum door. (^) This flapgate can be regulated manually to control saltwater access. A flapgate will be attached on the impoundment side to aIlow saltwater entry during the high tide while retaining the water in the pool during the low tide. (The gates^ can be raised or lowered at 3cm interrrals.) A splashboard riser will also be attached to the culvert on the impoundnent side. This is needed to remove water from the surface area to maintain water level objectives.
These trunks allow for flooding and draining the inpoundment with a minimum of effort. Structures of this design will control water levels automatically as the tide rises and ebbs, once they are adjusted. The riser (^) structure allows for the di-scharge of excess waters (^) above a pre-set leveI.
Edwin B. Forsythe NWR is located on the Atlantic Ocean in southeastern New Jersey about 10 miles north of Atlantic City. It was created in L984 by conbining the former Brigantine and Barnegat National Wildlife Refuges. Both fotmer Refuges lrere established under the authority of the Migratory Bird Conservation Act to preserve^ estuarine habitats important to the Atlantic brant (Branta^ bernicla) and to provide nesting habitats for black ducks (Anas nrbrioes) and rails (Rallus spp). The most abundant habitat (over (^301000) acres) is estuarine narsh, most of which has been ditched in the past for mosguito control. The marshes and irnpoundments provide (^) habitat for a great diversity of
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refuge only had one day that reached unhealthy standards. (^) A total (^) of 61351 acres of saltmarsh and barrier beach has been designated as a national wilderness and is therefore considered a Class I airspace under the C1ean Air Act.
Soils/Topographv (^) - The refuge lies entirely within the Atlantic Coastal Plain. Elevations range from 6 feet below sea level to approximately 5O feet above mean sea level.
The topography of the refuge is typical of the coastal marshes of New Jersey, where uplands taper gradually to a wide band of saltmarsh terminating in shallow bays. These bays are protected^ from the ocean by barrier beaches, protecting^ the refuge marshes from direct lrave action.
Soils in the refuge consist of unconsolidated guartz gravel, sand, silt, and clay of Cretaceous and Tertiary age overlaid by a veneer of fluvial sand, gravel, silt, and clay of (^) Quaternary and Recent age. two najor soil categories are the sulfaguents (^) - Sulfihenists and Manahawkin-Atsion- Berryland associations.^ These^ soils^ are^ nearly level, poorly to^ very^ poorly^ drained,^ with^ mineral and organic^ soils^ on^ tidal^ flats,^ organic^ and sandy soils on lowlands, and sandy soils on the uplands.
Geology/Hydrolocry (^) - The najor^ water^ table aguifer underlying the refuge is the^ Kirkwood-Cohansey system which dates from Miocene^ and Pliocene Epochs. The Ki-r]<wood Fornation consists^ primarily of sand, sj.It, and clay while the^ Cohansey Sand^ is chiefly unconsolidated quartz^ sand with some gravel and many clay beds. This system provides nost of the potable water to the refuge.
Several artesian aquifers underlie the Kirlcwood- Cohansey system and are tapped to a lesser extent for public^ and^ donestic^ supply.^ Pleistocene^ and Recent age deposits overlie the Kirkwood-Cohansey formations and contain sand, gravel, siIt, peat, and organic muck. Some shallow wells from these formations may be tapped locally for domestic use.
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mosquito ditches occur extensively throughout the marsh and several more recent shallow nosquito control impoundnents can also be found.
Forested wetlands (^) have water tables at or (^) near the surface (^) during dry periods of the year. (^) During the wet period of spring and early sunmer, areas with up to L2 to 18 inches of standing water may occur. Numerous artesian streams flow west to east (^) through the (^) forested wetland into the saltnarsh and (^) as Rhodehamel (1970) (^) notes, rrln^ the winter, the influx of ground water (^) discharge to^ the streams with temperatures of about 12"C (54-l') usually prevents^ freezing from bank to bank, even when air temperatures are substantially below freezinq. tt
These open streams are extremely important to black ducks during severely cold weather when other open-water areas freeze, preventing^ the ducks from reaching their food supply.
Surface/Tida1 Water (^) - Surface waters on the refuge. are comprised of freshwater impoundments fed by creeks and springsi freshwater forested bottomlands at the upland/narsh edge; permanent salt bays, creeks, and ponds;^ and temporary^ tidal pools. (^) I{ost of the surface of the saltmarsh is inundated by a high tide once^ every^12 hours, with the highest tides^ occurring on^ the^ new^ and^ fuIl moons.
B. BIOIPGICAL RESOURCES
1 Vegetation (^) - Vegetation transects have been periodically (^) conducted in both impoundnents since their establishment in the L950s. The most recent West Pool transect was conducted in 199L. This nas the first tirne the survey has been conducted since 1985. In^ 1980,^ one^ of the^ most^ notable conclusions drawn from^ the^ transects^ was^ the higher than expected diversity^ of^ food^ plants. Three species^ of^ smartweeds^ (Polvcronum^ spp.^ ) , three species^ of^ spikerushes (Eleocharis^ sp.^ ) , Echinochloa walteri,^ two^ species^ of cattails (Twpha sp. (^) ) , Cyoerus striqosis, (^) @ minor, Scirpus validus,^ Phvlolucca americana,^ and^ Elatine americana $rere relatively cornmon^ throughout the impoundment where conditions were^ appropriate. AIso very evident was the abundance^ of^ (Phragmites sp. (^) ) on the higher islands.
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specific (^) species due to poor (^) visibility through the water;^ however, the three species of spikerush recorded in the 1985 suney were identified in the 1991 sun ey.
The diversity of the plant^ species occurring on Transect (^) #f in the West Pool has declined over the years. (^) In the 1982 surnrey, 31 species of vegetation were recorded; in 1985, 18 species were identified and in L991, L7 species were recorded on Transect (^) #f.
Out of 1L1 plots^ sampled in 1991, 18 (168) vrere open water completely devoid of vegetation growth and 47 (422) additional plots were 2.5 to 858 devoid of vegetation. The total percent^ of open water (nud) in 1991 was 42.5 percent^ and frequency of occurrence was 66.7 percent.
Plant associations and approximate percent^ of each within the $Iest Pool are as follows:
Slender spikerush (Eleocharis
spikerush (Eleocharis narvula) Phragrmites communis
hydropiperoides), broadleaf
saltmarsh fleabane (Pluchea
(Scirpus validus)
452
3sz Lsz
sz
The nost recent^ East^ PooI^ vegetation^ transects were conducted in Septenber of^1989 and^ 1990.^ A total of 20 transects were established and sampled on the nesting islands (Appendix^ 71. Twenty-five species of vegetation were encountered, 22 in L and 21 in L990. Approximately 54 and 57 percent of the plots within the transects contained vegetation associated with nesting islands in 1989 and 1990, respectively. Phracrmites had the greatest significant increase in percent cover and frequency of occurrence and had extended its presence (^) to one additional transect which indicates this species is expanding throughout the East Pool. A 20 percent increase in frequency of occurrence of groundsel^ tree (Baccharis halimifolia) and^ the^ appearance^ of^3 upland
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saltnarsh vegetation has occurred.
A total of 47 species of vegetation were identified in a L988 surivey which transected (^) the East PooI in two locations. This sulivey (^) did not concentrate on the nesting islands as (^) did the L989/9O sunreys (Appendix 8).
In general, the East PooI is comprised of the following plant associations:
Saltmeadow cordgrass (Spartina patens) and saltmarsh fleabane (Pluchea purnurascens) Dwarf spikerush (Eleocharis^ narvula) Phracrmites communis Wild millet (Echinochloa^ walteri), saltmarsh cordgrass (Spartina alterniflora), sedge (Cvperus stricrosus) (^) , groundsel^ tree (Baccharis halinifolia), Pennsylvania smartweed (Polygonum pennsylvanicum), (^) and germander (Teuchrim (^) canadense) Approximately thirty minor species
402
202 252 r.o
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During the past fifteen years, the open water vegetation ratio in the East PooI has shifted toward the shallow open water and unvegetated mud flats.
Vegetation (^) in the saltmarsh surrounding the impoundrnents is doninated by saltnarsh cordgrass (Spartina (^) alterniflora) and saltmeadow cordgrass (S. patens).^ Other grasses found on the saltmarsh include: glassvort (Salicornia^ spp. (^) ), saltgrass (Distichlis spicata) (^) , black grass^ (Juncus creradi)^ , big cordgrass (Spartina cvnosuroides) and olney threesquare (Scirpus olnevi). Marsh elder (fva fnrtescens) and groundsel^ bush^ (Baccharis halimifolia) occupy higher sites, especially soil piles along mosquito ditches, while several dredge. spoil areas support pure stands of common reed (Phracrmites communis).
Submerged aguatic vegetation found^ in^ shallow bays, tidal pools^ and creeks^ includes^ eel^ grass (Zostera (^) marina), widgeon grass (Ruppia maritima), smartweeds (Polyclonum^ spp.^ ) , pondweeds
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a Threatened and Endanqered Species (^) - Federally designated (^) species found within the Brigantine (^) impoundments are the (^) bald eagle and peregrine^ falcon, both listed (^) as endangered. The inpoundnents (^) and surrounding saltmarsh are used by wintering (^) and nigrating bald eagles for short durations. (^) A peregrine falcon nesting tower was erected (^) on the I{estlEast PooI crossdike in (^) 1975, with 4 peregrines (^) hacked each year until (^) L979. The first successful nest occurred (^) in 1980 with one young^ produced.^ Since that time, dD additional L4 young^ have been produced (^) from the tower, with 1989, L990, and (^) LggL having the greatest^ success with 4 young, 3 young, and 3 young^ produced,^ respectively.
There are several species (^) relying on the refuge that are listed by the State of New Jersey as threatened (^) or endangered. These species include osprey, Ieast tern, black skimmer, great (^) blue heron, Northern harrier, and Ameri-can (^) bittern.
Waterfowl (^) and Other Waterbirds (^) - The coastal wetlands of New (^) Jersey are of international importance (^) to wintering waterfowl. In L990, 358 of the Atlantic Fl1may black duck population (^) and 668 of the brant population were recorded in New Jersey during the rnid- winter inventory conducted by the Service. In the L99O/9L aerial sur:veys conducted by refuge staff, peak^ numbers of birds were recorded on December 5 when 851570 birds lrere obsenred on both the Brigantine and Barnegat Divisions (Appendix 10). The Brigantine Division had a total of 82,LSL birds composed of 488 Atlantic brant, 33t snow geese, L black ducks, and 5t green-winged (^) teal (Anas crecca). Average weekly ground (^) survey results specifically (^) for the impoundurent area (East and West (^) Pools) are presented (^) in Appendices LL and (^) l-2. The 1990 bird usage in the East and West (^) Pools averaged 13,070 and 36,9O7 respectively. (^) A winter concentration of 10, OO0 black ducks (^) was obse:rred in the East PooI on January (^) 5, L99L, which is not unconmon during the nigrations. (^) A total of 81- species (^) of birds have been identified using the pools. (^) Conrnon species of waterfowl include American black duck, green-winged teaI, blue-winged teal (Anas^ discors),
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American widgeon (Anas^ americana), snow geese, (^) Canada geese (Branta (^) canadensis), Northern shoveler (Anas^ cllrpeata), and Northern pintail^ (Anas^ acuta).^ Common^ marsh and water^ birds include great^ blue^ herons (Ardea (^) herodias) (^) , great egrets (Casrnerodius albus), snowy egrets (Eqretta^ thula),^ black- crowned night herons (Nvcticorax^ nycticorax), American bittern (Botaurus^ lentiginosus), and glossy (^) ibis (Plegadis (^) falcinellus). Common shorebirds include semipalmated sandpipers (Calidris pusilla),^ semipalnated plovers (Charadrius semipalmatus), yellowlegs (Trinqa spp. (^) ) , and dunlins (Calidris alpina).
Both the West and East Pools provide nesting and brood-rearing habitat for nany species of ducks, including^ recent^ annual^ productions^ of several hundred black^ ducks^ (Table^ below). Canada goose and^ mute^ swan^ (Cyqnus^ olor) broods are^ commonly observed^ in^ the iurpoundnent area. other bird^ species^ such^ as willets (Catoptrophorus semipalmatus) and rails also nest on the pool islands and dikes. In the 1950s and early 70s,^ waterfowl production (^) was at its peak (^) in the iurpoundrnents. Through the years^ the decline of the guality of the inpoundment wetlands has resulted in a decline in black duck, mallard, and gadwall^ (Anas^ strepera) production. There has also been a decline in the diversity of species breeding in the iurpoundments. Canada goose^ production, however, has increased^ since^ 1985.
Waterfowl Production Estimates Uslng the "Tradltionaln Drive-Around Method (Inpoundments OnIy)
198s 1986 L987 1988 1989 1990^1991 351 400 450 19s 283 345 193
SPECIES Black Duck Mallard Gadwall Blue-winged Teal Plntalls Canada Geese TOTAIS
98 13
58 26 9 15
45 3 2
97 49 10
5
t- L25 82 L72 80 83 391 4L 505 666 788 325 448 879^626
50 18 L
66 77
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Mammals (^) - Approxinately^33 species^ of^ mammals occur on^ the refuge.^ The^ most^ commonly obsenred species^ in the pool islands^ and surrounding dikes include the^ Eastern cottontail (Sv1vilagus^ floridanus),^ red^ fox (Vulpes vulpes), gray fox (Urocyon
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