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Ecological Engineering 36 (2010) 1709–1718

Contents lists available at ScienceDirect

Ecological Engineering

journa l homepage: www.e lsev ier .com/ locate /eco leng

ffects of nourishment on the form and function of an estuarine beach

ancy L. Jacksona,∗, Karl F. Nordstromb, Sherestha Sainia, David R. Smithc

Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, NJ 07102, USAInstitute of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ 08901, USAUnited States Geological Survey, Leetown Science Center, Kearneysville, WV 25430, USA

r t i c l e i n f o

rticle history:eceived 16 February 2010eceived in revised form 5 July 2010ccepted 19 July 2010

eywords:eolian transporteach nourishmentstuarine beacheach scarpediment activation

a b s t r a c t

Beach nourishment programs in estuaries can enhance shore protection, but they decrease habitat suit-ability by creating higher berms and wider backshores than would occur under natural conditions. Use ofsediment sources from outside the area can result in sedimentary characteristics that differ from nativesediments on the surface and at depth, altering conditions for both aeolian transport to dunes and inter-stitial fauna. Field data were gathered on an estuarine beach to determine differences in beach profilechange, depth of sediment reworking, and potential for aeolian transport due to nourishment. Data weregathered over a 20-month period 6 months prior to nourishment, 3 days after nourishment, 6 months afternourishment, and 14 months after nourishment when the beach was mechanically graded to eliminate avertical scarp in the foreshore. The nourishment consisted of 87,900 m3 of sediment emplaced to create a1.34-km-long, 30-m-wide berm 2.3 m above mean tide level. Seven percent of the fill was removed fromthe profile within 6 months after nourishment, accompanied by 7 m in horizontal retreat of the artificialberm. The fill on the backshore remained above the zone of wave influence over a winter storm season andwas separated from the active foreshore by the scarp. Nourished sediments on the intertidal foreshorewere significantly different from native sediments to a depth of 0.20 m below the surface. A lag surfaceof coarse sediment formed by deflation on the backshore, resulting in a rate of aeolian transport <2% of

the rate on the wave-reworked foreshore.

Nourishing a beach to a level higher than would be created by natural processes can create a profile thatcompartmentalizes and restricts transport of sediment and movement of fauna between the foreshoreand backshore. Mechanical grading can eliminate the scarp, allow for faunal interaction, and reestablishwave reworking of the backshore that will facilitate aeolian transport. Using an initial design to nourishthe backshore at a lower elevation and allowing a dune to provide protection against flooding during

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. Introduction

Beach nourishment operations are increasing in number andcale, and nourishment is now the principal means of shore pro-ection in many countries (Hamm et al., 2002). Nourishment is

ost often associated with exposed coasts with intensive levelsf development or great recreational value (Finkl, 1996), but it islso important in estuaries, where it can potentially provide beachabitat as well as shore protection (Nordstrom, 1992; Shipman,

001; Jones and Hanna, 2004; Fenster et al., 2006; Andrade etl., 2006). National, state and private agencies have an interest insing beach nourishment to enhance natural values while protect-

ng human development, but written documentation of volumes,

∗ Corresponding author. Tel.: +1 973 596 8467; fax: +1 973 596 3586.E-mail address: jacksonn@njit.edu (N.L. Jackson).

fi2mblhem

925-8574/$ – see front matter © 2010 Elsevier B.V. All rights reserved.oi:10.1016/j.ecoleng.2010.07.016

carp from forming and eliminate the need for follow-up grading.© 2010 Elsevier B.V. All rights reserved.

ediment composition and purposes of beach nourishment is lack-ng for many operations in estuaries, and there are few studies thatssess the effects of beach nourishment in estuarine environmentsfter the fill is emplaced (Nordstrom, 1992; Shipman, 2001; Jacksont al., 2002).

Considerable attention is devoted to the longevity of beachourishment projects in ocean environments and their perfor-ance relative to pre-project predictions (Dean and Yoo, 1994;

apobianco et al., 2002), differences in the textural properties ofll and native sediment (Kana and Mohan, 1998; Horn and Walton,007) and the negative environmental impacts of beach nourish-ent (Speybroek et al., 2006). Studies of the way nourishment can

e used to restore habitat are rare (Nordstrom, 2005). A goal of eco-ogical engineering is to develop new sustainable ecosystems thatave human and ecological value (Mitsch, 1998). The opportunityxists to make nourishment projects designed for shore protectionore compatible with ecological goals including offshore impacts

1710 N.L. Jackson et al. / Ecological Engin

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Miller et al., 2002). Considerations of beach volumes and sedi-ent budgets are important, but physical shoreline conditions areprimary influence on biological processes (Rice, 2006), and beachorphology and sediment characteristics have great influence onhether nourishment projects can function as natural environ-ents (Zelo et al., 2000; Botton et al., 2006). These aspects of

ourishment are important in estuaries where shorelines providecological functions and services in addition to shore protection.

Nourishment can decrease habitat value as well as enhance it,epending on whether the sediment characteristics resemble there-nourished beach and when and how the sediment is introducedo the fill area (Nelson, 1993). The time dimension is importantecause the sediment characteristics and initial form of the nour-

shed beach will be dissimilar to the pre-nourished beach andequire time to achieve equilibrium with the wave energy regime.he speed of this naturalization process is a function of wave energyhich is low in estuarine environments.

Sandy beaches in estuaries are characterized by a narrow back-hore (<10 m), steep planar foreshore (6–9◦) and a broad, relativelyat, bay bottom or low tide terrace (Nordstrom, 1992; Fenster etl., 2006). Reported wave heights of locally generated waves rangerom 0.15 to 0.50 m with periods of 2–5 s and they break directly onhe foreshore and convert directly to swash. The width of the swashone can be only 3 m during small storms (Jackson and Nordstrom,993). Ocean waves entering estuaries during storms can result

n increased wave periods (>5.0 s) and swash runup widths (up to.0 m) (Nordstrom et al., 2006). The low-wave energies on estuarineeaches limit reworking by storm erosion and post-storm deposi-ion (Fig. 1). Nordstrom (1992) reports upper foreshore losses ofver 3.0 m3 m−1 and landward displacement of over 4 m duringbserved storm breaking wave heights of 0.4–0.8 m and periods

f 3.4–4.5 s. The cycle of offshore transport to a break point bar,ollowed by post-storm deposition by swash bar migration that isommon on ocean beaches is absent (Nordstrom, 1992) and theayward extent of sediment exchange is generally <10 m from the

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ig. 2. Map of the regional setting (A) and study site (B), and orthophotoquad of the pre-nnd longshore limits of the nourishment operation (scale 1:24,000).

eering 36 (2010) 1709–1718

reak in slope that separates the foreshore from the bay bottomr low tide terrace (Hardaway et al., 1989). Potential for longshoreediment transport occurs because short period estuarine wavesndergo little refraction and may break at a relatively sharp angleo the shoreline. Despite longshore sediment losses, the restric-ion in the horizontal and vertical extent of reworking on estuarineeaches implies that naturalization of the remaining fill sedimentill be a slow process.

The purpose of this paper is to examine the short-term geo-orphic and sedimentologic changes that occur on an estuarine

each as a result of beach nourishment and to identify the impli-ations of these changes to nourishment practice, using field datarom Slaughter Beach, in Delaware Bay (Fig. 2). Efforts are concen-rated over a time frame encompassing one winter to determinehether processes occurring over a storm season are sufficient to

ework the beach into a naturally functioning landform or whetherdaptive management is required to supplement natural processes.he study evaluates three of the physical aspects of beach changemportant to the success of nourishment operations, including (1)volution of the cross-shore shape of the beach profile; (2) depthf reworking and sorting of the fill sediment; and (3) changes inhe potential for aeolian transport. These three physical aspectsre examined in terms of four phases in the evolution of a nour-shed beach: (1) before nourishment; (2) days after fill sediments emplaced; (3) after the beach is reworked by storms; and (4)fter the first adaptive management project, which, in this case,onsisted of mechanically grading the beach.

. Background

For nourishment operations, geometry, placement and sed-ment composition are three important considerations (Dean,002). Scale of beach nourishment operations (alongshore lengthnd sediment volume) is an important indicator of success ofrojects designed for protection of property from storm damagend space for beach recreation. Length of the fill will influence theate of sediment loss from the project ends as the newly nourishedhoreline equilibrates to the wave regime (Dean, 2002). Cross-hore volume per unit length is a function of design form (bermlevation and width, closure depth). Most nourishment operationsn estuaries involve placement of fill on the intertidal foreshore andre designed to have wider backshores and higher berm elevationso protect against wave erosion and overwash. Creation of a higherm has the added advantage of increasing beach volume without

he foreshore. In estuaries, placement of fill on the bay bottom isiscouraged or prevented by environmental regulations in many

urisdictions due to the biological productivity there (Nordstrom,992; Shipman et al., 2000).

ourished shoreline in 1997 (C) showing beach, upper portion of the low tide terrace

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Placing more sediment on the backshore is not without prob-ems. Backshores that are built wider and higher than naturaleaches may not be reworked by waves except during major stormsnd are susceptible to formation of a vertical scarp at the upper limitf wave reworking at high spring or storm tides. Scarps are com-on on nourished beaches in Delaware Bay (Jackson et al., 2005). A

carp may form a barrier to both wave runup and aeolian transportrom the foreshore to the backshore and interfere with movementf fauna across the beach (Crain et al., 1995; National Researchouncil, 1995). A key issue is whether storm wave heights andater levels in a given year will be great enough to overtop the

carp and rework the beach to allow the backshore to evolve.Differences in grain size characteristics introduced in nourish-

ent operations can result in differences in the form and mobilityf estuarine beaches and their drainage (Nordstrom, 1992). Estu-rine beaches have been nourished with source material dredgedrom offshore (Douglass and Weggel, 1987) and adjacent creeks ornlets (Fenster et al., 2006) or mined from inland sand and graveluarries (Shipman et al., 2000). Use of non-beach sources can result

n departures in sediment size and sorting from native material.re-existing surface gravel will be buried. Gravel is a prominent andcologically valuable characteristic of many low energy beachesNordstrom, 1992; Rice, 2006; Ciavola and Castiglione, 2009), sohis loss may be locally important.

Fill will be reworked in the active layer mobilized by breakingaves and swash, and the textural properties of sediment remain-

ng on the foreshore will become similar to native material in grainize and sorting. The depth of reworking by estuarine waves isimited, causing Jackson et al. (2002) to hypothesize that the undis-urbed layer of fill may be closer to the surface than the deptheached by burrowing organisms. Field data are needed to docu-ent how the textural properties of the fill sediment change in

esponse to the mobilization process.The great initial width of dry beach in fill areas leads to increased

ikelihood of transport of the sand fraction by wind soon after nour-shment (Draga, 1983; van der Wal, 1998; Marqués et al., 2001),ut this increase in aeolian transport can be short-lived. Preferen-ial removal of the surface sand can leave a lag surface of coarserhell or gravel that subsequently resists aeolian transport (Davis,991; Psuty and Moreira, 1992; van der Wal, 1998, 2000). Shellavements can form within weeks and can remain in areas that areot periodically flooded (van der Wal, 1998). Nourishing a beacho a high elevation will decrease the likelihood that the lag surfaceill be reworked by wave runup. The reworking of the seawardortion of a poorly sorted but predominantly sandy fill by wavesontributes to removal of finer sizes and burial of gravel in theand-dominant sediment matrix. Reworking of the landward por-ion of the fill by wind leaves the more poorly sorted coarse sandnd gravel fraction as the dominant cover. These processes resultn sediment that is usually best sorted on the surface of the fore-hore, more poorly sorted at depth within the inactive fill and mostoorly sorted and coarsest on the surface of the deflated back-hore (Namikas, 1992). Rates of aeolian transport across nourishedeaches should reflect these differences in susceptibility of the sur-ace to entrainment by wind, but quantitative data are lacking forourished estuarine beaches. The many studies of aeolian transportn beaches indicate that beach width can be a critical factor influ-ncing the rate of aeolian transport and delivery of sand to dunesDavidson-Arnott and Law, 1990), but the characteristics of surfaceediment can overcome the advantages of source width. Nour-

shment operations can greatly increase the potential for aeolianransport and creation of dunes by natural processes, but the lagurface can prevent this natural process from occurring. Field datare needed to document the degree to which these processes areestricted by nourishing a beach above the level of wave reworking.

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eering 36 (2010) 1709–1718 1711

. Study area

Slaughter Beach is on an eroding, sandy, former overwash bar-ier on the east facing side of Delaware Bay (Fig. 2A and B). Thesearriers are found in low-wave-energy environments and haveeen less studied than their ocean counterparts (Nordstrom, 1992;ooper et al., 2007).

Beach nourishment has been used extensively for hazard reduc-ion on the populated barriers on the west side of the bay. The-km-long, developed portion of Slaughter Beach was modifiedy the State of Delaware in shore protection projects, includingonstruction of groins, artificial beaches and an artificially creatednd shaped dune. Unpublished state records reveal that 30–55 mong timber groins were constructed between 1940 and 1957. A520-m3 perched beach was constructed in 1979, and 596,000 m3

f sediment were placed between 1958 and 1985, which was theost recent project prior to the one monitored in this study (2005).

he largest fills were in 1975–1976, when about 347,500 m3 weremplaced. Nearly all of the nourishment projects were conductedy hydraulic dredge using sources in the bay. Much of the fill wassed to create the protective dune, which is far larger than natu-al estuarine dunes. The old groins were buried by the 1975–1976lls. They were uncovered near the base of the foreshore in 2004ut appeared to have negligible effect on transport of sedimentlongshore.

The nourishment project evaluated here was designed for shorerotection and was constructed in October–November 2005. Theontractor (Cottrell Contracting Corporation) placed hydraulicallyredged sediment from an offshore borrow site about 500 m off-hore and placed about 87,900 m3 of sediment on the beach toreate a 30 m wide berm 2.3 m above mean tide level. The sourceas selected specifically for the project, but no prior grain size anal-

ses were conducted in the borrow area. Future projects will benefitrom current efforts to map sub-bottom sediments for nourishmentperations (Wilson and Madsen, 2006). The longshore limits of thell extended from the southern limit of human development (about.9 km from the monitoring site) for a distance of 1.34 km to theorth. Sediment in the fill is predominantly quartz and feldspar.ean grain size of sediment on the foreshore is in the range ofedium to coarse sand. The volume placed is within the range ofodeled scenarios for restoring 5–10 years of estimated shoreline

osses and providing protection from a storm event with a 5- to0-year return interval (PBS&J, Inc., 2010).

Prevailing winds are from the west and blow offshore, but low-ressure centers bring strong onshore winds from the northeastnd southeast. Slaughter Beach is exposed to waves generatedithin the bay by local winds and waves entering from the Atlanticcean. Sediment impoundment at shore perpendicular structures

uggests that net longshore sediment transport is to the north.urial of the groins by recent nourishment operations has pre-ented them from interfering with sediment transport and therere no variations in morphology alongshore (Fig. 2C). Tides areemi-diurnal with a mean range of 1.4 m and a spring range of 1.7 mNOAA, 2006). The active foreshore is normally about 20.0 m wideuring spring tides and had a slope of 9.0◦ prior to the nourishment.gently sloping low tide terrace extends bayward of the base of the

oreshore. The break in slope that separates the foreshore from theow tide terrace is 0.2 m below mean low water and 3.2 m belowhe elevation of the backshore. The artificial dune landward of theeach was undercut by storm waves prior to the 2005 nourishment

peration.

Several species utilize the beach for spawning, foraging andransgressing or inhabiting the interstitial sediment matrix. The

ost important species include the horseshoe crab (Limulusolyphemus), the diamondback terrapin (Malaclemys terrapin), and

1 Engineering 36 (2010) 1709–1718

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our species of migratory shorebirds including the Red KnotCalidris canutus), Sanderling (Calidris alba), Ruddy Turnstone (Are-aria interpres), and Semipalmated Sandpiper (Calidris pusilla) thatorage in the intertidal zone (Clark et al., 1993; Tsipoura and Burger,999). The horseshoe crab spawns on the intertidal foreshore andemales bury their eggs to a depth of 0.20 m; exhumed horseshoerab eggs are a significant portion of the diet of the migratoryhorebird population (Tsipoura and Burger, 1999). Diamondbackerrapins nest in sandy deposits such as beaches and dunes aboveormal high tides (Palmer and Cordes, 1988). Nests are excavatedo a depth of 0.10–0.20 m below the sand surface (Montevecchi andurger, 1975).

. Methodology

The analysis presented in this paper was part of a 2-year studyo assess the influence of beach nourishment on horseshoe crab eggiability and development (Jackson et al., 2008). The data gather-ng program included obtaining a topographic profile and sedimentata spanning a 20-month period 6 months before and 14 monthsfter the nourishment and conducting two detailed 49-day time-eries experiments of beach processes (waves, water level) andesponses (profile change, depth of sediment reworking and sedi-ent characteristics) in May and June 2004 and 2006.

.1. Beach topography and sediment characteristics

Changes in beach topography and depths of sediment activa-ion during the two 49-day experiments were measured from theops of 10 mm diameter rods placed at 2 m intervals across theoreshore. Rods were placed along two sets of paired transects (sep-rated by a distance of 3 m alongshore); the sets of paired transectsere separated 13 m alongshore. These rods enable measurement

f changes of the sand surface to within 0.5 mm. A loose fittingasher was placed over the rods to determine depth of activation

ccording to the procedure in Greenwood and Hale (1980). Dataere gathered during daylight low tides throughout the two 49-ay field deployments. Comparison of profiles alongshore revealed

ittle difference during the two 49-day experiments so data pre-ented are from one profile over time. Beach topography over theong term was determined from rod and transit surveys. Topogra-hy was measured 6 months before nourishment, 3 days after fillas placed (29 November 2005), 6 months after nourishment and

fter the state graded the beach to remove a scarp that formed inhe foreshore (11 January 2007).

The likelihood for locally generated waves to rework the beachver the long term was assessed using data on wind speed andirection from Lewes, DE (NOAA, 2005–2006), located 21 km southf the site. Data from 1-h records were used to identify periodshen onshore wind speeds were >8.0 m s−1 for durations of at leasth during tidal inundation of the foreshore. These times of highind speed and deep water generate the greatest wave heights

nd cause the most conspicuous morphologic changes.Data to determine wave height and period were collected dur-

ng the two 49-day experiments using pressure transducers placed5 m bayward and 5 m landward of the base of the foreshore. Dataere recorded at 4 Hz in 17.1 min records. Wave heights reported

re significant heights (Hs = 4�) and periods are peak periods fromhe spectral estimates of the time series.

Sediment samples were taken at four locations across the fore-hore to determine differences in grain size characteristics withepth. Samples were taken when the long term topographic pro-les were measured. The set of samples taken after the first wintertorm season were taken 7 months after nourishment, rather than

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Fig. 3. Profiles from before and after the nourishment and after grading.

months after, to include a storm on 7 June 2006. Sampling loca-ions were normalized by the foreshore width (0 = the base of theoreshore and 1.0 = the upper limit of swash uprush) (Fig. 1). Theppermost samples taken 3 days after the fill was placed were onhe backshore rather than the upper foreshore because the nor-

al upper foreshore location had not yet been reworked by waves.ediments were sampled using 20-mm-long cores, sliced in 50-m-long segments and analyzed for grain size and sorting of the

and and granule fraction. Sediment samples were washed, driednd sieved at 1/2 � intervals. Mean (Mz) and sorting (�I) were cal-ulated using measures that make use of the � (−log2) distributionFolk, 1974). The gravel fraction (>2.0 mm) is represented as a per-ent of total weight of the sample. A Mann–Whitney test was usedo determine whether significant differences occurred in grain sizeharacteristics with depth.

.2. Aeolian sediment transport

Data on aeolian transport were collected 6 months after nour-shment, by which time the backshore was deflated by winter storm

inds. Data were gathered during the second 49-day experimentn 11, 22, and 23 May 2006, when blowing sand was observed.ind direction and speed were measured just landward of the

each scarp (Fig. 3) that separated the foreshore from the fill on theackshore. Wind direction was measured using a compass orientedlong the modal direction of falling sand grains. Wind speed wasbtained at 2 m elevation above the beach surface for five 1-minntervals during each trapping event using a Nielsen–Kellermanestrel 2000 weather meter that records average and maximumpeeds.

Sediment transport was measured using vertical cylindricalraps (Leatherman, 1979), having a trapping height of 0.37 m and aidth of 43.0 mm. The cylindrical design is a standardized method

or measuring aeolian transport in the field (Sherman et al., 1998).ield testing of cylindrical traps reveals that they are efficient oneaches at wind speeds close to the threshold of sediment move-ent (Gares et al., 1996) as occurred during this study.Traps were emplaced just after aeolian transport was observed

nd remained until wind speed died down. Trapping times variedrom 48 min (11 May) to 75 min (22 May). One trap was placedayward of the uppermost wrack line on the upper foreshore, onll 3 days (Fig. 3). The second trap was placed on the middle of theackshore, on 11 May when the winds were obliquely onshore. This

ocation was preferred to the most downwind position at the base

f the dune, where there was a pronounced drop in wind speed andransport potential. The backshore trap was placed just landwardf the beach scarp on 22 and 23 May, when winds were obliquelyffshore.

N.L. Jackson et al. / Ecological Engineering 36 (2010) 1709–1718 1713

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Grain size characteristics were determined from trap samplesnd from 200 mm × 200 mm surface samples taken to a depth ofmm at a distance of 5 m upwind of each trap on each day. An addi-

ional sediment sample was taken at mid backshore after the scarpas graded and the beach had been reworked by storm waves.

he 5 mm sampling depth is sufficient to capture the gravel that isartially embedded within the sediment matrix, while represent-

ng the surface characteristics that influence sediment entrainmentnd transport. Beach and trap samples were sealed in air-tight con-ainers, weighed that day, air dried and re-weighed to determine

oisture content before being sieved.

. Results

.1. Topographic changes

The beach profile prior to fill emplacement (Fig. 3) had a nearlylanar 20 m wide foreshore and a 6 m wide bayward-sloping back-hore. The elevation of the backshore/dune contact was about 1.0 mbove mean high water and the berm elevation was 1.3 m abovesl. The active foreshore slope was 5.7◦. The nourishment oper-

tion increased the sediment volume seaward of the base of theune by 60.6 m3 m−1 and the volume above mean high water by5.3 m3 m−1. The elevation of the base of the 0.15 m high scarp onhe post-nourishment beach in 2005, 3 days after the completion ofhe project (Figs. 3 and 4), was at the elevation of the normal upperimit of swash uprush during non-storm spring tides. The slope ofhe active foreshore was 6◦, 3 days after nourishment and 6 monthsfter nourishment. About 19.0 m3 m−1 of the fill was removedrom the beach profile over the 6-month period after nourish-

ent (Fig. 3). Most of the removal was above mean high water andas apparently alongshore, as revealed in the lack of topographic

hange on the lower foreshore or offshore of the break in slope. Esti-ated gross longshore transport rate is 17 000 m3 m−1 at the site

nd net transport (9510 m3 m−1) is to the north (Maurmeyer, 1978).bout 7 m of horizontal retreat of the artificial berm occurred, and

he scarp height increased to 0.30 m. The base of the scarp 6 months

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fter nourishment and after grading.

fter nourishment was at a similar elevation to the base of the dunerior to the nourishment (Fig. 3).

Sediment volume after grading in 2007 was 1.9 m3 m−1 greaterhan the post-nourishment volume 3 days after placement, indicat-ng that more sediment moved into the area than left by longshoreransport. This could have been associated with a pulse of sedi-

ent delivered by natural processes or by earth moving equipment.etailed data for either process are lacking.

.2. Sediment reworking

Changes in bed elevation over consecutive tidal cycles and depthf sediment activation provide an indicator of the degree of rework-ng of the fill sediment. Average net bed elevation change acrosshe foreshore monitored in the 49-day experiments in May–June004 and 2006 is within ±0.01 m (Fig. 5A and C). Maximum sig-ificant wave heights measured daily near high water during 2004ere greater than during 2006 (Fig. 5) and there is greater depth

f activation in 2004. The average activation depths during bothonitoring periods are <0.05 m (Fig. 5B and D). The greatest net

hange in bed elevation on the foreshore (0.06 m of erosion) dur-ng 2004 occurred during a moderate intensity storm during apring tidal cycle. Significant wave heights averaged 0.40 m overhe 6-h tidal cycle with a maximum of 0.45 m during high tide.

ave periods averaged 4.2 s. These wave conditions were associ-ted with onshore winds averaging 13.6 m s−1. In 2006 the greatestet change on the foreshore (0.09 m of erosion) occurred during atorm that lasted over one tidal cycle when significant wave heightseached a maximum of 0.32 m and periods were 3.3 s measured atigh tide. Winds were onshore and averaged 10.4 m s−1 (Fig. 6).

.3. Sediment size

The sand fraction is finer on the upper foreshore than the loweroreshore 6 months before fill placement (Table 1). Grain size andorting are similar with depth across the mid-upper to lower fore-hore. Sands on the upper foreshore are finer with depth. The

1714 N.L. Jackson et al. / Ecological Engin

Fig. 5. Time averaged net change (A and C) and depth of activation (B and D) with10th and 90th percentile (n = number of profiles), and wave heights monitored dur-itsF

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ng May–June 2004 and 2006. The nondimensional foreshore width extends fromhe upper limit of swash (1) to the base of the foreshore (0). The width of the fore-hore extended from 6 to 26 m in 2004 and from 22 to 42 m in 2006 as identified onig. 3.

argest percent gravel is on the lower foreshore, a condition com-on on estuarine beaches (Nordstrom, 1992).There was no sediment analysis of the fill from the borrow area.

he sediment characteristics from the depth samples of the back-hore environment are the closest approximation of the textural

roperties of the fill. The sand samples from the two locationsear mid-foreshore are the most complete over time, are in theone of greatest sediment activation, and are used to assess dif-erences in sediment size due to nourishment and subsequent

ig. 6. Daily significant wave heights during high water measured during the 2004nd 2006 monitoring periods.

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eering 36 (2010) 1709–1718

eworking. Fill sediment (November 2005) is finer than the pre-ious mid-foreshore sediment. The Mann–Whitney test revealedhat differences in mean grain size with depth at the two loca-ions are significant (p = 0.03). The lower percentage of gravel rightfter nourishment could be due to greater amounts of sand in theource area offshore and burial of the former surface gravel thatad ample time to accumulate on the eroding beach over the twoecades since the previous nourishment. Seven months after nour-

shment (June 2006) the sediment is still similar to the fill sedimentcross the mid-foreshore and at depth. This condition could be dueo the lack of wave energy to rework the foreshore sufficientlyor sediment to equilibrate to a bay wave regime. During the 7-

onth period, there were a total of 19 tidal cycles when hourlynshore wind speeds exceeded 8.0 m s−1 for more than 5 h duringidal inundation of the foreshore.

Grading and subsequent reworking of the profile by January007 resulted in redistribution of sediment, with coarser sands atid-foreshore than 6 months after nourishment. Grading resulted

n sediment characteristics similar to the pre-nourished beachTable 1) and a similar profile form but with a wider backshoreFig. 3).

.4. Aeolian transport

The rate of aeolian transport on the foreshore greatly exceededhe rate on the backshore during the three events monitoredTable 2). Surface sediments on the backshore had far more gravelnd were more poorly sorted than on the wave-reworked fore-hore. A rough surface reduces aeolian transport rates (Blumbergnd Greeley, 1993) and the greater roughness on the backshore andhe larger grain sizes resisted deflation, resulting in far lower ratesf sand transport for each day (Table 2).

Although little sand moved on 22 and 23 May, the data indicatehat rates of transport on the foreshore are greater than on theackshore by two orders of magnitude. The stronger onshore windsn 11 May provide better perspective on the effect of differences inurface conditions during winter storms when greater wind speedsccur. These data reveal the diminished potential for natural dunerowth by aeolian transport due to the development of a lag surface.

The sediment sample taken on the backshore after the beachas graded had a mean of 0.67 mm and a sorting value of 0.44, with no gravel. The grain size was only slightly coarser thann the foreshore on days when transport was measured, but theide, dry surface increases the future potential for transport to

he dune. Elimination of the scarp facilitates periodic reworking ofhe backshore by swash, which can replenish the sand fraction andestrict formation of the lag surface.

. Discussion

Storm waves change the shape of a naturally functioning beachrofile, but post-storm reworking re-establishes pre-storm pro-le shapes, and in the process, reworks the sediment. A naturaleach has a backshore at the elevation of storm wave runup. Waveprush during the largest storms will erode the dune but will alsoeplenish the sand-size particles on the backshore, providing theource of wind-blown sand to replenish the dune. The net result isbeach that is mobile but with subenvironments that interact byatural processes following cycles of erosion and accretion. Build-

ng a beach that is overly wide and high will restrict the degree ofnteraction between the foreshore and backshore and between theackshore and dune. Backshore widths have been increased 10-foldfter nourishment in estuarine environments (Fenster et al., 2006)reventing interaction between the foreshore and dune.

N.L.Jackson

etal./EcologicalEngineering

36 (2010) 1709–17181715

Table 1Mean and sorting of the sand and granule fraction and percent of the gravel fraction of sediments across the foreshore before and after nourishment.

Substrate elevations Backshore Foreshore location (nondimensional width)

Upper (1.0–0.75) Mid–upper (0.75–0.50) Mid–lower (0.50–0.25) Lower (0.25–0.0)

Mean (mm) Sorting (�) Gravel (%) Mean (mm) Sorting (�) Gravel (%) Mean (mm) Sorting (�) Gravel (%) Mean (mm) Sorting (�) Gravel (%) Mean (mm) Sorting (�) Gravel (%)

6 months before fill: June 20040.00–0.05 0.52 0.52 2.0 0.51 0.51 2.2 0.74 0.66 50.8 1.12 0.75 29.00.05–0.10 0.42 0.57 11.4 0.60 0.62 0.7 0.85 0.88 44.5 0.99 0.77 36.70.10–0.15 0.59 0.61 0.2 0.62 0.61 10.3 0.90 0.99 38.6 0.91 0.79 44.20.15–0.20 0.46 0.52 8.3 0.65 0.72 13.4 0.66 1.03 28.5 0.93 0.78 46.4

3 days after fill: November 2005Surface 0.79 1.27 52.60.00–0.05 0.55 1.19 21.8 0.33 0.60 0.0 0.55 0.87 11.9 0.70 0.97 29.60.05–0.10 0.49 1.14 16.9 0.30 0.55 0.0 0.53 1.17 10.3 0.80 1.11 25.00.10–0.15 0.78 1.19 19.0 0.38 0.67 0.0 0.46 0.96 12.5 0.57 0.88 24.80.15–0.20 0.54 1.10 25.3 0.45 0.72 0.0 0.49 1.02 3.9

7 months after fill: June 2006Surface 0.32 0.45 0.0 0.41 0.24 3.2 0.49 0.38 34.30.00–0.05 0.31 0.47 0.2 0.48 0.54 7.6 0.56 0.69 23.10.05–0.10 0.41 0.64 0.4 0.74 0.84 28.4 1.00 0.91 21.90.10–0.15 0.32 0.63 5.3 0.65 0.78 31.7 1.29 0.96 44.00.15–0.20 0.53 0.86 1.9 0.66 0.84 28.7 0.91 1.44 74.0

14 months after fill: January 2007Surface 0.52 0.51 0.0 0.73 0.33 11.0 0.90 0.55 2.60.00–0.05 0.86 0.58 0.0 0.97 0.59 43.7 1.00 0.88 9.20.05–0.10 1.19 0.67 7.1 0.81 0.99 51.6 0.72 0.77 21.00.10–0.15 0.61 0.51 0.3 0.60 0.72 20.5 1.12 0.80 50.10.15–0.20 0.77 1.16 31.9 0.88 0.81 27.7 1.16 1.03 34.4

1716 N.L. Jackson et al. / Ecological Engin

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eering 36 (2010) 1709–1718

Nourishment at Slaughter Beach resulted in a finer sand fractionnd less gravel on the intertidal foreshore, in keeping with the find-ngs by Jackson et al. (2005) that nourished beaches in Delaware Bayend to have finer, better sorted sediment and a lower percentage ofravel than eroding unnourished beaches. The textural propertiesf sediment influence temperature, moisture and oxygen gradi-nts in the beach matrix (McLachlan and Turner, 1994) that mayffect the suitability for species that inhabit the interstitial envi-onment. Sediment used in nourishment operations that departsrom native material can reduce abundance for prey (Peterson et al.,006) but it is assumed that effects on interstitial fauna are not sig-ificant when sediment matching occurs (Nelson, 1993; Nationalesearch Council, 1995). Differences in characteristics of nourishednd native sediment on estuarine beaches may be critical whererganisms burrow deeper than the active layer such as the caseith horseshoe crabs.

A scarp was conspicuous up to 6 months after completion of theourishment project. Scarp longevity is determined by the intensityf swash uprush relative to scarp height, and a scarp will continueo migrate up the beach if the uprush is constrained (Sherman andordstrom, 1985). Beach change, and equilibration of nourishmentrofiles in low-wave-energy environments is an event-driven pro-ess (Elko and Wang, 2007), and if fill material is placed too highn the beach, a series of severe storms may be needed to adjustopography to conform to a natural state (Larson et al., 1999). Theow energy of the swash on this estuarine beach and the greateight of the fill prevented the overtopping of the scarp that wouldliminate it by natural processes. The nourished beach did notave a natural shape, even after an entire winter storm season,ut it had equilibrated after 14 months with mechanical grading.he slope of the foreshore after grading is similar to the slope ofhe foreshore after nourishment and it is likely that a new scarpill form, which may require re-grading in the future. Ecological

ngineering relies on nature’s ability to self-design a resilient sys-em without frequent human intervention (Jørgensen and Mitsch,989; Mitsch, 1998) indicating that a lower berm elevation wouldave provided a better initial design. Creed et al. (2000) documenthe lack of correlation between profile slope and sediment size athe berm crest of nourished beaches. This would appear to makeesign slopes in this region of the profile a matter of preference,ith profile shapes chosen to optimize natural or hazard reduc-

ion goals. Nourishing a beach to a level higher than would bereated by natural processes can create a beach form that com-artmentalizes and restricts transport of sediment and movementf fauna. Establishing interconnectivity of ecosystem componentss an important principle of ecological engineering (Gattie et al.,006; Huang et al., 2009). Mechanical grading can reestablish arofile slope that is more compatible with wave conditions and canacilitate wave runup that would reduce the likelihood of forma-ion of a scarp, allow for faunal interaction between the foreshorend backshore and periodically rework the backshore, prevent-ng development of a lag layer and allowing aeolian transport toccur across the entire width of the beach. Grading to a lowerackshore elevation at the scarp location, while maintaining a fore-hore slope that is more compatible with local wave conditions,ould require placing some sediment on the inner low tide terrace

Fig. 3).The wide initial backshore could have contributed to aeolian

ransport to the dune soon after the fill was emplaced, althought is also likely that the prevailing westerly winds would have

ransported the surface sands into the swash zone rather than theune. The lag surface on the deflated backshore after nourishmentiminished subsequent aeolian transport. Sediment from upwindources can be transported into and across a lag surface (McKennaeumann, 1998) and more sand could have been transported to

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N.L. Jackson et al. / Ecological

he dune at Slaughter Beach during onshore winds if the scarp didot prevent this from happening. Thus the high elevation of theourished beach that prevents wave reworking and contributes tocarp formation greatly reduces the value of the backshore boths a sediment source and as a transport surface for wind-blownand.

The narrow backshore width of a natural estuarine beach placeshe active foreshore close to the vegetated upland. A change in theelationships between the upland, beach and aquatic environmentsan diminish the potential for interaction between them and cre-te harsher conditions for fauna using the foreshore (Rice, 2006).n overly wide beach will displace the foreshore bayward. Theidth of beach fill in estuaries must reflect the need to minimizeeposition on the low tide terrace, allow for interaction betweenhe upland and foreshore, and prevent the upland from eroding atn accelerated rate. The width of fill should be narrow enough tollow for some erosion of the dune during storms but not enough toompletely destroy its structural integrity as a barrier to overwashandward of it. This concern about the width limit for estuarineeaches need not apply to ocean beaches, where cross-shore envi-onmental gradients can be hundreds or thousands of meters wideMcLachlan, 1990).

The alternative of nourishing the backshore at a lower elevationnd allowing a dune to provide protection against wave uprushnd flooding during major storms would eliminate the need forollow-up grading of the beach as an adaptive management strat-gy. Beaches and dunes are part of the same sediment exchangeystem under natural conditions (Psuty, 1988). The elevation cho-en for the backshore could correspond to the height of reworkingy a storm of at least annual frequency/magnitude. The greaterotential for aeolian transport across a wave-reworked backshoreould result in a more naturally appearing and functioning dune

hrough time. Restrictions on placing fill on the bay bottom in someurisdictions would mean that a smaller volume of sediment wouldave to be used, and a dune would have to be incorporated intohe initial design of projects intended to protect coastal infrastruc-ure from flooding. This alternative of building a lower, smallereach was viable at Slaughter Beach, where the protective duneas already in place and where there was no restriction on placingll on the low tide terrace.

The available time window for dredging in estuaries (that mustvoid times of biological productivity) and the slow reworkingf low energy beaches may preclude attainment of a fully wave-eworked profile prior to the time when the foreshore is utilized byauna. Adaptive management is an approach that is being broadlypplied in many ecosystem restoration projects (Williams et al.,009; Jones et al., 2010) and may be required to facilitate natu-al functioning of beach nourishment projects. Profile reshapings an action that is often taken in the initial construction phasef beach nourishment projects but it may be appropriate at timeshroughout the life of the fill.

. Conclusions

Emplacing beach fill at dimensions higher and wider than nat-ral estuarine beaches can eliminate the exchange of sedimentetween foreshore and backshore caused by winds, waves andwash and prevent movement of fauna. Placing the fill at a lowerlevation can retain the natural connectivity, and nourishing theeach more frequently, using less sediment each time, can reduce

he likelihood of burying fauna on the low tide terrace. Beach nour-shment projects designed for shore protection can be made moreompatible with ecological goals and lead to self sustaining nat-ral habitats if designs better mimic the dimensions of natural

andforms.

H

H

eering 36 (2010) 1709–1718 1717

cknowledgements

We are grateful to Bill and Shawna McSpadden for access toheir property. This publication is the result of research spon-ored by New Jersey Sea Grant with funds from the Nationalceanic and Atmospheric Administration (NOAA) Office of Searant, U.S. Department of Commerce, under NOAA grant numberA060AR4170086, and New Jersey Marine Sciences Consor-

ium/New Jersey Sea Grant with funds appropriated by the State ofew Jersey. The statements, findings, conclusions, and recommen-ations are those of the author(s) and do not necessarily reflect theiews of New Jersey Sea Grant or the U.S Department of Commerce,JSG-10-772.

eferences

ndrade, C., Lira, F., Pereira, M.T., Ramos, R., Guerreiro, J., Freitas, M.C., 2006. Moni-toring the nourishment of Santo Amaro estuarine beach (Portugal). J. Coast. Res.SI39, 776–782.

lumberg, D.G., Greeley, R., 1993. Field studies of aerodynamic roughness length. J.Arid Environ. 25, 39–48.

otton, M.L., Loveland, R.E., Tanacredi, J.T., Itow, T., 2006. Horseshoe crabs (Limuluspolyphemus) in an urban estuary (Jamaica Bay, New York) and the potential forecological restoration. Estuaries Coasts 29, 820–830.

apobianco, M., Hanson, H., Larson, M., Steetzel, H., Stive, M.J.F., Chatelus, Y.,Aarninkhof, S., Karambas, T., 2002. Nourishment design and evaluation: appli-cability of model concepts. Coast. Eng. 47, 113–135.

iavola, P., Castiglione, E., 2009. Sediment dynamics of mixed sand and gravelbeaches at short time scales. J. Coast. Res. SI56, 1751–1755.

lark, K.E., Niles, L.J., Burger, J., 1993. Abundance and distribution of migrant shore-birds in Delaware Bay. Condor 95, 694–705.

ooper, J.A.G., Lewis, D.A., Pilkey, O.H., 2007. Fetch-limited barrier islands: over-looked coastal landforms. GSA Today 17 (3), 4–9.

rain, A.D., Bolten, A.B., Bjorndal, K.A., 1995. Effects of beach nourishment on seaturtles: review and research initiatives. Restor. Ecol. 3, 95–104.

reed, C.G., Bodge, K.R., Suter, C.L., 2000. Construction slopes for beach nourishmentprojects. J. Waterw. Port Coast. Ocean Eng. 126, 57–62.

avidson-Arnott, R.G.D., Law, M.N., 1990. Seasonal patterns and controls on sed-iment supply to coastal foredunes, Long Point, Lake Erie. In: Nordstrom, K.F.,Psuty, N.P., Carter, R.W.G. (Eds.), Coastal Dunes: Form and Process. John Wileyand Sons, Chichester, pp. 177–200.

avis, R.A., 1991. Performance of a beach nourishment project based on detailedmulti-year monitoring: Redington Beach, FL. In: Coastal Sediments 91, AmericanSociety of Civil Engineers, New York, pp. 2101–2115.

ean, R.G., 2002. Beach Nourishment: Theory and Practice. World Scientific Pub-lishing Company.

ean, R.G., Yoo, C.-H., 1994. Beach nourishment in presence of seawall. J. Waterw.Port Coast. Ocean Eng. 120, 302–316.

ouglass, S.L., Weggel, J.R., 1987. Performance of a perched beach—Slaughter Beach,Delaware. In: Proceedings of Coastal Sediments ‘87, American Society of CivilEngineers, New York, pp. 1385–1398.

raga, M., 1983. Eolian activity as a consequence of beach nourishment observationsat Westerland (Sylt), German North Sea coast. Z. Geomorphol. Suppl. Band 45,303–319.

lko, N.A., Wang, P., 2007. Immediate profile and planform evolution of a beachnourishment project with hurricane influences. Coast. Eng. 54, 49–66.

enster, M.S., Knisley, C.B., Reed, C.T., 2006. Habitat preference and the effects ofbeach nourishment on the federally threatened northeastern beach tiger beetle,Cicindela dorsalis: Western shore, Chesapeake Bay, Virginia. J. Coast. Res. 22,1133–1144.

inkl, C.W., 1996. What might happen to America’s shoreline if artificial beachreplenishment is curtailed: a prognosis for southeastern Florida and other sandyregions along regressive coasts. J. Coast. Res. 12, iii–ix.

olk, R.L., 1974. The Petrology of Sedimentary Rocks. Hemphill, Austin, TX.ares, P.A., Davidson-Arnott, R.G.D., Bauer, B.O., Sherman, D.J., Carter, R.W.G., Jack-

son, D.W.T., Nordstrom, K.F., 1996. Alongshore variations in aeolian sedimenttransport: Carrick Finn Strand, Ireland. J. Coast. Res. 12, 673–682.

attie, D.K., Schramski, J.R., Bata, S.A., 2006. Analysis of microdynamic environ flowsin an ecological network. Ecol. Eng. 28, 187–204.

reenwood, B., Hale, P.B., 1980. Depth of activity, sediment flux and morphologicalchanges in a barred nearshore environment. In: McCann, S.B. (Ed.), The Coastlineof Canada. Geological Survey of Canada, Ottawa, pp. 89–109 (Paper 80-10).

amm, L., Capobianco, M., Dette, H.H., Lechuga, A., Spanhoff, R., Stive, M.J.F., 2002.

A summary of European experience with shore nourishment. Coast. Eng. 47,237–264.

ardaway, C.S., Thomas, G.R., Li, J.-H., 1989. Chesapeake Bay Shoreline Study:Interim Report. Virginia Institute of Marine Science, Gloucester Point, VA.

orn, D.P., Walton, S.M., 2007. Spatial and temporal variations of sediment size ona mixed sand and gravel beach. Sediment. Geol. 202, 509–528.

1 Engin

H

J

J

J

J

J

J

K

L

LM

M

M

M

M

M

MM

M

N

N

N

N

N

NN

N

P

P

P

P

P

R

SS

S

S

S

T

v

v

W

718 N.L. Jackson et al. / Ecological

uang, J.C., Mitsch, W.J., Zhang, L., 2009. Ecological restoration design of a streamon a college campus in central Ohio. Ecol. Eng. 35, 329–340.

ackson, N.L., Nordstrom, K.F., 1993. Depth of activation of sediment by plungingbreakers on a steep sand beach. Mar. Geol. 115, 143–151.

ackson, N.L., Nordstrom, K.F., Smith, D.R., 2002. Geomorphic—biotic interactions onbeach foreshores in estuaries. J. Coast. Res. SI36, 414–424.

ackson, N.L., Smith, D.R., Nordstrom, K.F., 2005. Comparison of sediment character-istics on nourished and un-nourished estuarine beaches in Delaware Bay, NewJersey. Z. Geomorphol. 141, 31–45.

ackson, N.L., Smith, D.R., Nordstrom, K.F., 2008. Physical and chemical changes inthe foreshore of an estuarine beach: implications for viability and developmentof horseshoe crab Limulus polyphemus eggs. Mar. Ecol. Prog. Ser. 355, 209–218.

ones, K., Hanna, E., 2004. Design and implementation of an ecological engineeringapproach to coastal restoration at Loyola Beach, Klegberg County, Texas. Ecol.Eng. 22, 249–261.

ones, K., Pan, X., Garza, A., Lloyd-Reilley, J., 2010. Multi-level assessment of ecolog-ical coastal restoration in south Texas. Ecol. Eng. 36, 435–440.

ana, T.W., Mohan, R.K., 1998. Analysis of nourished profile stability following thefifth Hunting Island (SC) beach nourishment project. Coastal Eng. 33, 117–136.

arson, M., Hanson, H., Kraus, N.C., Newe, J., 1999. Short- and long-term responsesof beach fills determined by EOF analysis. J. Waterw. Port Coast. Ocean Eng. 125,285–293.

eatherman, S.P., 1979. A new eolian sand trap design. Sedimentology 25, 303–306.arqués, M.A., Psuty, N.P., Rodriguez, R., 2001. Neglected effects of eolian dynam-

ics on artificial beach nourishment: the case of Riells, Spain. J. Coast. Res. 17,694–704.

aurmeyer E.M. 1978. Geomorphology and Evolution of Transgressive EstuarineWashover Barriers Along the Western Shore of Delaware Bay. Ph.D. Thesis,University of Delaware.

cKenna Neumann, C., 1998. Particle transport and adjustments of the boundarylayer over rough surfaces with an unrestricted, upwind supply of sediment.Geomorphology 25, 1–17.

cLachlan, A., 1990. The exchange of materials between dune and beach systems.In: Nordstrom, K.F., Psuty, N.P., Carter, R.W.G. (Eds.), Coastal Dunes: Form andProcess. John Wiley, Chicester, pp. 201–215.

cLachlan, A., Turner, I., 1994. The interstitial environment of sandy beaches. Mar.Ecol. 15, 177-121.

iller, D.C., Muir, C.L., Hauser, O.A., 2002. Detrimental effects of sedimentation onmarine benthos: what can be learned from natural processes and rates? Ecol.Eng. 19, 211–232.

itsch, W.J., 1998. Ecological engineering—the 7-year itch. Ecol. Eng. 10, 119–130.itsch, W.J., Jørgensen, S.E., 1989. Ecological Engineering: An Introduction to

Ecotechnology. John Wiley and Sons, New York.ontevecchi, W.A., Burger, J., 1975. Aspects of the reproductive biology of

the Northern diamondback terrapin Malaclemys terrapin. Am. Midl. Nat. 94,166–178.

amikas, S.L., 1992. Beach Nourishment Performance at South Beach, Sandy Hook

Unit, Gateway National Recreation Area. Rutgers University Institute of Marineand Coastal Sciences, New Brunswick, NJ (Technical Report 99-22).

elson, W.G., 1993. Beach restoration in the Southeastern US: environmental effectsand biological monitoring. Ocean Coast. Manage. 19, 157–182.

ational Oceanic and Atmospheric Administration (NOAA), 2005–2006. Local Cli-malotological Data—Lewes, Delaware. National Climatic Data Center.

W

Z

eering 36 (2010) 1709–1718

ational Oceanic and Atmospheric Administration (NOAA), 2006. Tide Tables 2006:East Coast of North and South America. NOAA, Washington, DC.

ational Research Council, 1995. Beach Nourishment and Protection. NationalAcademy Press, Washington, DC.

ordstrom, K.F., 1992. Estuarine Beaches. Elsevier Science Publishers, New York.ordstrom, K.F., 2005. Beach nourishment and coastal habitats: research needs for

improving compatibility. Restor. Ecol. 13, 215–222.ordstrom, K.F., Jackson, N.L., Smith, D.R., Weber, R.G., 2006. Transport of horseshoe

crab eggs by waves and swash on an estuarine beach: implications for foragingshorebirds. Estuarine Coast. Shelf Sci. 70, 438–448.

almer, W.M., Cordes, C.L., 1988. Habitat Suitability Index Models: DiamondbackTerrapin (Nesting)—Atlantic Coast. U.S. Fish Wildlife Service Biological Report82 (10.151), 18 pp.

BS&J, Inc., 2010. Management plan for the Delaware Bay beaches: final report.Prepared for the Delaware Department of Natural Resources and EnvironmentalControl, Tampa, Florida.

eterson, C.H., Bishop, M.J., Johnson, G.A., D’Anna, L.M., Manning, L.M., 2006. Exploit-ing beach filling as an unaffordable experiment: benthic intertidal impactspropagating upwards to shore birds. J. Exp. Mar. Biol. Ecol. 338, 205–221.

suty, N.P., 1988. Sediment budget and dune/beach interaction. J. Coast. Res. SI3,1–4.

suty, N.P., Moreira, M.E.S.A., 1992. Characteristics and longevity of beach nourish-ment at Praja da Rocha, Portugal. J. Coast. Res. SI8, 660–676.

ice, C.A., 2006. Effects of shoreline modification on a northern Puget Sound beach:microclimate and embryo mortality to surf smelt (Hypomesus pretiosus). Estu-aries 29, 63–71.

herman, D.J., Nordstrom, K.F., 1985. Beach scarps. Z. Geomorphol. 29, 139–152.herman, D.J., Jackson, D.W.T., Namikas, S.L., Wang, J., 1998. Wind-blown sand on

beaches: an evaluation of models. Geomorphology 22, 113–133.hipman, H., 2001. Beach nourishment on Puget Sound: a review of existing projects

and potential applications. In: Puget Sound Research 2001. Puget Sound WaterQuality Action Team, Olympia, WA, pp. 1–8.

hipman, H., Stoops, K., Hummel, P., 2000. Seattle Waterfront Parks: Applications ofBeach Nourishment. Washington Coastal Planner’s Group, Seattle, WA.

peybroek, J., Bonte, D., Courtens, W., Gheskiere, T., Grootaert, P., Maelfait, J.-P.,Mathys, M., Provoost, S., Sabbe, K., Steinen, E.W.M., van Lancker, V., Vincx, M.,Degraer, S., 2006. Beach nourishment: an ecologically sound coastal defencealternative? A review. Aquat. Conserv.: Mar. Freshw. Ecosyst. 16, 419–435.

sipoura, N., Burger, J., 1999. Shorebird diet during spring migration stopover inDelaware Bay. Condor 101, 635–644.

an der Wal, D., 1998. The impact of the grain-size distribution of nourishment sandon aeolian sand transport. J. Coast. Res. 14, 620–631.

an der Wal, D., 2000. Grain-size-selective aeolian sand transport on a nourishedbeach. J. Coast. Res. 16, 896–908.

illiams, B.K., Szaro, R.C., Shapiro, C.D., 2009. Adaptive Management: The U.S.Department of the Interior Technical Guide. Adaptive Management Work-ing Group, U.S. Department of the Interior, Washington, DC, http://www.doi.

gov/initiatives/AdaptiveManagement/TechGuide.pdf.

ilson, B., Madsen, J., 2006. Acoustical methods for bottom imaging in estuaries.Sea Technol., 43–46.

elo, I., Shipman, H., Brennan, J., 2000. Alternative Bank Protection Methods for PugetSound Shorelines. Shorelands and Environmental Assistance Program, Wash-ington Department of Ecology, Olympia, WA (Ecology Publication 00-06-012).