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Abstract Climate change and subsequent human responses have had drastic impacts on salt

marshes. Sea level rise, increased storm intensity, and coastal development have caused a 50% loss in wetlands globally in the 20th century. Shoreline hardening has become a popular method to reduce effects from climate change; however, hardening often fails, and the consequences of failure are typically greater than the problems hardening is meant to prevent. The need for alternative, sustainable, and durable shoreline stabilization methods is evident. This paper outlines the creation and testing of an abiotic salt marsh mimic, with the intent of it being a sustainable alternative to shoreline hardening. The mimic was evaluated in terms of fish utilization, wave attenuation, and sediment and nutrient processes. A business model was developed that could be used to market and implement the salt marsh mimic product.

Keywords

Coastal Engineering, Fish utilization, Green infrastructure, Living shorelines, Salt marsh, Sediment and nutrient processes, Wave attenuation

1. Introduction

As a result of climate change, sea level rise and increased storm intensity have become more common throughout the world. Tidal floodplains, coastal wetlands, and estuarine regions overall will likely become the most susceptible to these climatic changes and can cause extensive losses in ecosystems and human development through enhanced erosion (Peterson, 2008). In order to protect these assets and reduce erosion, humans have implemented various responses; one of the first methods used was gray infrastructure (also referred to as shoreline hardening or armoring), which includes bulkheads, seawalls, sills, revetments, jetties, groins and riprap (Browne, 2011; Shipman, 2009; Gittman, 2015). Approximately 14% of the United States’ continental shoreline has already been armored as of 2015 (Gittman, 2015). This hardening of shorelines, however, is likely to yield more damage in the instance of failure—the once protected land becomes exposed and vulnerable to wave energy, storm surge, and erosion (Fig. 1). Gray infrastructure has also been found to impede natural processes, such as transgression, the process of the shoreline migrating landward, and the reduction of habitat complexity (Peterson, 2008; Gittman, 2015). These processes along with other negative outcomes of hardening shorelines will likely violate the Clean Water Act due to their impacts on coastal wetlands inhibiting these ecosystems from adapting to climate change (Peterson, 2008). Over two decades ago, the EPA projected that by 2100, marshes in the continental US will be reduced by 65% (Peterson, 2008). Within the last century, 50% of all wetlands, which include salt marshes, have been lost worldwide (Millennium Ecosystem Assessment, 2005; Lotze et al. 2006).

As the negative impacts of hardening shorelines on ecological processes and human property became more apparent, new methods of shoreline protection had to be developed and implemented. One of the most prominent methods is green infrastructure, a term which is appearing more frequently, carrying with it different meanings to different parties (Benedict, 2001). In terms of shoreline protection, green infrastructure protects natural resources and

habitats while protecting human development and property; in other words, conservation techniques have the potential to complement land development (Benedict, 2001). Examples of green infrastructure include dunes, wetlands, beaches, artificial reefs, and living shorelines (“Federal Highway Administration”). Living shorelines are an effective and ecologically responsible alternative to hardened shorelines because they utilize natural habitats to protect shorelines(Davis, 2008). During the last decade, nature-based infrastructures have been implemented where natural and man-made structures are combined (Sutton-Grier, 2015). These new, “green” hybrid methods have been shown to enhance coastal resilience in terms of flooding and erosion protection (Sutton-Grier, 2015).

In this capstone project, we investigated nature-based infrastructure alternatives in an attempt to invent our own economically sustainable method of shoreline protection that would also provide ecological support as an artificial salt marsh environment. Salt marshes became our main focus because of how they function and their valuable role in living shorelines. A salt marsh is defined as an intertidal grassland found naturally behind barrier island systems and estuaries (NOAA, 2014). They provide numerous ecological benefits, substantially contribute to the biological productivity of estuaries, and have the ability to respond to sea level rise (Peterson, 2008). Salt marshes induce sedimentation where wave energy is attenuated due to water flow reduction by friction and baffling, which causes the deposition of sediments (Morgan et al. 2009). Salt marshes also provide habitat, including nursery habitat, and protection to estuarine species; young fishes, shrimp, and shellfish utilize marshes and many of these species support higher trophic levels that are endemic, threatened, endangered, and commercially important, resulting in high primary and secondary production (Barbier et al. 2011; Boesch and Turner 1984; Peterson, 2008). In turn, this boosts the production of economically and ecologically important fishery species (Boesch and Turner 1984; MacKenzie and Dionna 2008). Further benefits to humans include salt marshes’ provision of raw materials and food, coastal protection, erosion control, water purification, maintenance of fisheries, carbon sequestration, tourism, recreation, education, and research (Barbier et al. 2011; Davy et al. 2009). More simply put, there is no shortage of value offered by salt marshes towards humans or the environment at large.

Several of these categories were valued in US dollars by Barbier et al. (2011), demonstrating the economic value of salt marshes in various capacities. For example, on coastal regions in Florida, the capitalized value of one acre of salt marsh in terms of recreational fishing is estimated to be $6,471 and $981, respectively (Bell 1997; Barbier et al. 2011). Even more valuable, is the calculated value of carbon sequestration by global salt marsh of 2.1 Mg C/ha: $30.50·ha-1·yr-1. Carbon sequestration serves a pivotal role in generating biological productivity, biogeochemical activity, and sedimentation—processes that contribute to vegetation, coastal geomorphology and sediment deposition (Barbier et al. 2011). Groot et al. (2012) provided monetary values for different ecosystem services per biome (values in Int.$/ha/year, 2007 price levels); coastal and inland wetlands (which encompass various salt marsh types) had a “total economic value” of $193,845 and $25,682, respectively. With these considerations, salt marshes are not only valuable to the ecosystem but also to humans.

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Figure 1. E

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2. Metho

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d ecosystem site. More spattenuates w

o separate sithe shore of line faces BoWithin this splicate A wandy shorelinem west of the

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ogue Sound site, there wes placed in fes. The secoe IMS site an

idea of creatral benefits olaced in arealeast improv

ent our produng wave attety to riprap sriment usingof the Bogu

a sandy shorend create scoment is remoddition, whend loss (Ship

salt marsh and

e tested biolowe measuredow it affects

uct our expere of Marine Sand consistsere three repfront of the rond site was nd also faces

ting a natureof salt marshas where saltve the negatuct anywherenuation, anstructures, sig wooden dowue Banks soueline, and anour where woved, increa

en bulkheadspman, 2009)

encroaching on

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Figure 2. O

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moved to proesented one r100 dowels

Our two study

Utilization

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nts.

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ls/m2, 100 doter of 3/16’’

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sites and the d

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vestigate theities, we collnts. Minnowd, and retrievcted in Nove

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w traps were ved 2 hours ember to red

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knowledge o

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ocations of the v

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ulkhead. Camd abbreviatedreatment lev

of the project

ed four 1 meone and eachments for eaels/m2 (Fig. 2We inserted icking up outertidal zoneors that coulde was markedfrom each otto complete 3 meter sideion. On the shead site onlatment. Threts original st

various plots.

ots and compg minnow trahours beforeide. A total ofrom season

mp Albemard as BH in sovels, data obtt’s potential

eter by 1 meth given a difach replicate2). We utilizthe dowels b

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pare fish useaps and conde high tide atof three minnnality. The tra

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re used to weEach tank co

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s

ces for diffeanks behind made up them, which weeigh the styrompared twos were filled

nds of the tanrs. The fish u off of Oaks

ed and used imus argenteue for each triwith the diffefrom two trisecond hour

res containincant differen

t and baited 3). Fish collets were averae only one sA) tested forhoc t-tests as

w trap design ubulkhead site w

erent densitieIMS to simu

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smith Boulevin the experi

us), and Atlanial. In trial o

ferent fish spials were colr in order to ng fish in eacnces using pa

with dog fooected in the taged across pecies, pinfi

r significant ssessed varia

used in fish colwith the minnow

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llection (left) aw trap float vis

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om Bogue Soture of each were caugh

innow traps fish (Lagodonde (Menidia 10 fish per t

buted as evenhe fish visib

n hour-long aor each tank ts.

ally acceptedounted, idenplicates. No r found in thin fish count

en each dens

and a sible (right).

mesocosm ex densities use created bynk. Bricks, dnserted into tvs. 150, andound. GoProplot every 1

ht at the IMSand a seine nn rhomboidemenidia). N

tank and for nly as possibble in each piacclimatizatitrial were an

d practice whntified, and

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xperiments. Wsing the samy using 1 m bdive weights the styrofoam

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Figure 4. E

2.4 Wave

2.4.1 In

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Examples of th

e Attenuation

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ight from presensors wer

crements witmeasure theighed down ched to a helter. After 24manner in ornother 24 ho

he mesocosm ta

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etermine the d change in wation measurepth and begit was the sitessure data fe used to methin the plot waves reachwith lead anlical anchor a4 hours of darder to reducours before b

ank setup.

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hing the plotnd lightly secand set such

ata collectionce the densitybeing collect

ss of the expas water pasprepared a la

00 dowels/mto be most a

re sensors plar pressure. Fos placed 2.95t (Fig. 5) Thcured to near

h that the topn, half of they of the plot ted and down

perimental mssed througharger plot th

m2 density. Thaffected by waced within our of the se5 meters in f

he four pressurby dowels w

p of the sensoe dowels wert to 50 dowelnloading the

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Figure 5. DEach senso

2.4.2 In

from the segmentsfluctuatiointo a sur

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2.5 Sedim

2.5.1 S

Bulkheaddepth of sufficientsedimentgrain sizekeep suctplaced on

Inthe core wwas fashithe top 1 scoop ouat 1 cm a

Diagram showor is assigned a

Data Analyn order to obtotal pressur

s, and the meons. A pressurface-elevati

nce of surfac

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n wave heigh

ment and Nu

Grain Size

ediment cord sites. The c10 cm. In tht sediment sut cores was te. A cap wastion on the cn the bottomn the lab, wawith a glass ioned by comcm of sedim

ut. The sedimand inserting

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ysis

btain water pre. The 6Hz ean pressureure spectrumion spectrum

ce-elevation

√2ση2. The w

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m in order to aters were sippipette with

mbining twoment, which ment sample g the extracti

ement of sensom the offshore s

pressure meareadings for

e was calculam was calculm. The surfac

n (ση2). Mean

wave height

as waves pa

esses

en from all pclear hollow f our experimtop layer wo

op 3 cm intathe top of thhe core. As tto hold the ephoned from

hout disturbino plastic scoowas typicallfrom each c

ion tool into

ors within the wsensor.

asurements, tr water pressated and subtlated and, usce-elevation

n wave heig

and water de

assed throug

plots within etubes that w

ment, a depthould be presact and undise tube once the core wasextracted sed

m cores, and ng the top laopula strawsly too far dowore was extrthe core unt

wave attenuatio

the atmosphsure were sptracted in or

sing linear wspectrum w

ght was t

epth graphs

gh the plot.

every replicawere hammerh of 10 cm werved. The msturbed in orit was hamm

s pulled fromdiments insidany remaini

ayer of sedims on top of eawn in the coracted by metil the tube w

on plot.

heric pressureplit into five-rder to leave

wave theory, was integrated

then calcu

were then u

ate, from botred into the s

was considermain goal ofrder to obsermered into thm the groundde. ing water wament. A miniach other in

ores to simpleasuring the was in the co

e was subtra-minute only the wawas convertd to determin

ulated us

sed to determ

th IMS and sediment to red to be f taking the rve a changehe ground tod, a cap was

as sucked froi extraction torder to rea

ly reach in antube, markin

ore at 1 cm d

acted

ave ted ne

sing

mine

a

in

om tool ch nd ng it

depth.

This method was done multiple times for each core in order to obtain enough sediment to use in the CILAS grain size analyzer. The samples containing larger particles and shell hash were run through a 2 mm sieve to ensure that the entire sample was 2 mm or smaller in grain size - which is a requirement of sediments when using CILAS grain size analyzer. Each core had one sub-sample taken to run through the grain size analyzer. Average grain size in micrometers was recorded for each sub-sample from every core.

2.5.2 Nitrogen Flux Experiment and Sediment Organic Matter

Continuous flow experiments were used to determine the fluctuations of dissolved gases in the water . Intact sediment cores were taken at each plot using plastic tubes measuring 6cm in diameter and 55 cm in length with the sediment measuring approximately 15cm deep. These were filled with approximately 400 mL of water and were collected at each plot at low tide in late November, 2016. An additional 105 L of water were collected from Bogue Sound as a reservoir for the continuous flow experiment. The cores were incubated in an environmental chamber set to the temperature of the water at the time of collection (17�) and under dark conditions. The cores were capped with a plexiglass top equipped with two O-rings to maintain an air- and water-tight seal. Each cap contained two ports with plastic tubing - one for inflow and one for outflow to ensure a well-mixed water column within the tube. Inflow water from the reservoir was aerated, unfiltered, and passed over cores at a flow rate of 1 mL per minute. The cores were then left to stabilize overnight before measurements began. 5 mL samples of the outflow water from the cores were taken at 17 and 21 hours after capping. After the 21 hour collection, a spike of sodium nitrate (30 µmol/L NaNO3) was added in order to simulate a nutrient loading event, such as a rainstorm. Samples were taken again at 41 and 45 hours after capping. The concentrations of dissolved nitrogen, oxygen, and argon levels were measured using a Membrane Inlet Mass Spectrometer (MIMS). The concentrations of gases were compared to samples of the inwater that were pumped through the same tubing but not through a core to account for possible changes in water chemistry because of the tubing or the pump. After completion of the flux experiment, samples of the top 2 cm of sediment from the cores were taken to determine the percentage of carbonaceous, organic matter based on the amount lost on ignition (Heiri et al., 1999). Samples were dried overnight at 105�, weighed, combusted for 5 hours at 525�, and then weighed again.

2.5.3 Benthic and Epiphytic Chlorophyll a Levels To determine benthic algal growth, the top 1 cm of sediment was sampled at each plot using a modified syringe. These samples were diluted with 10 mL of a methanol, acetone, and DI water solution in 45:45:10 proportions. The samples were then sonicated for 5 minutes and allowed to sit overnight in the freezer to reduce any photosynthetic processes. The solutions were then filtered through a 2 mm filter to filter out any large particulates that could interfere with the

spectromthen dilu

Samounts pulled frocm abovesolution a

3. Result

3.1 Fish

3.1.1 MD

the UNCabundancutilizatioand 150 dbut lesserindicatinvariance between

meter. The chted with 10 amples of epbeing produom the groune that. Theseand sonicate

ts

Utilization

Minnow TraDistinct trendC IMS study ce at each pln was lowesdowels per mr than utilizag increased were presenany of the d

hlorophyll a cµL of 10% hpiphytic algauced by the end and cut ae were then ped. The same

aps- IMS Studs in fish utilsite using relot density rest in the 50 dm2 plots. Fisation of bothfish abundan

nt between pdiffering plot

Figure 6. Avat the UNC I(n=3) with 0

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udy Site

lization wereeplicates A, Bevealed diffedowels per mh utilization

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verage numberIMS study site

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e observed aB, and C. A erences in th

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r of fish for eac. Each plot den

m2 as the contro

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among differunivariate an

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dowel densitt-tests did no

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read using a

o measure thel rods. The ually by a dae same acetousing the sp

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ity plot (± 1 SEd three replica

a spectromete

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pectrometer.

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nt (Fig. 6). Fiin both the 1

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umber of fish pThe bulkhead cead plots (BH A2.

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he trial utilizised 77% of Interestingly

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age fish abune bulkhead stn the two plotical signific

per sampling pecontrol plot conA, BH B, and B

ials investigas revealed a sthe 50 versued the 100 dthe fish-cony, in the 100se t-tests, difficance dem

with specific

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Figure 8. Pcomparing

3.2 WaveB

get an ideover the and eachwater prethinner wfluctuatio

Figure 9. Waction.

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e AttenuationBefore examiea of what w48 hours of dip represenessure than twith less flucons.

Water pressure

pictures at eachdensities were

n

ining actual was occurringsensor deplonts a low tidhe second 24

ctuations and

e measured ove

h plot density ine performed.

wave heightg while the soyment(Fig. de. The first 24 hours. Thi

d the last two

er a period of tw

n which fish co

ts, it is imposensors were9). Each pea

24 hours of dis is shown ino peaks appe

wo days, inclu

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uding the effect

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lyze the raw Pressure vardepth represion saw fewehat the first twwith a higher

ts of varying w

k trials. Three t

pressure datried significasents a high ter changes inwo peaks se

r frequency o

water level and

trials

ta to antly tide n eem of

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Figure 10.

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. Mean wave h

Wave heightsts informatiofference in diod. This canld have been

heights over 5-m

s appear to bon from the 5dowel densityn be assumedn more drasti

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be more extre50 dowels/my, but is liked because thic if it was c

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ly caused byhe incline in waused by the

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Figure 11.

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3.3 Sedim

3.3.1A

among al

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4. Discussion

4.1 Fish Utilization

Analysis of the minnow trap data from the IMS site indicated an increased fish presence in the higher marsh density treatments, although the relationship was not significant. Higher numbers of fish in the 100 and 150 dowels/m2 treatments may indicate a preference for salt marsh habitat with higher stem density. In the field, confounding factors such as wave intensity and existing topographic complexity at the different replicates may influence fish presence in certain treatments; the data from the bulkhead site illustrate the extreme variability that is possible even among the same density treatments. Comparatively, an analysis of the mesocosm experiments indicated that fish have a significant preference to marsh with intermediate stem density (100 dowels/m2) when many of the confounding factors present in the natural environment have been removed. This may be because an intermediate density allows for more room to maneuver around stems while still providing protection from predators. Future field experiments should span the entire year to determine if seasonality has an effect on fish preference. The trials we conducted all occurred during the month of November, a time when fish populations are low due to cold water temperatures. Extending trials to warmer months may result in a better indication of fish preference. Since the minnow traps were observed to trap only certain fish species, seining should be done to supplement the data and ensure a more accurate representation of the fish that utilize the area. Future mesocosm experiments should include a distinct control treatment to better represent the density preference of fish. Additionally, trials should be conducted at a time of day where the tanks receive full sun for the duration of the picture collection to eliminate the effects of shadows on fish movement and water visibility. Ideally, greater numbers of fish in even species distributions should be used for each trial to standardize observed fish response.

4.2 Wave Attenuation

Although the results from the wave attenuation portion of the experiment did not indicate that wave attenuation occurred, several important conclusions can be drawn from general patterns in the data as well as from previous studies. Our pressure sensors showed an overall decrease in wave heights despite the fluctuations throughout the mimic marsh plot. This indicates that perhaps with more data collection, the outliers in our data may have a less significant impact on the overall pattern. With less impact from the outliers, the patterns of decrease in wave action may be stronger and more significant. We can also conclude that a plot 3 meters in depth (perpendicular to shoreline) does not provide enough friction against the water to cause wave attenuation. In a previous study, it was shown that a 30 m long plot reduced waves by 94% (Knutson et al. 1982). Therefore, in future studies, it would be beneficial to construct plots about thirty meters in depth perpendicular to shore in order to maximize wave attenuation. In some cases, it may not be necessary to reduce waves by as much as 94%, so studies could be conducted that examine a wide variety of plot lengths to choose the most effective and cost efficient length of plot.

Along with the insufficient size of the plot, our chosen densities of 100 dowels/m2 and 50 dowels/m2 appear too low to cause significant wave attenuation over the 3 m plot depth. In natural salt marshes, the average density of stems ranges from 179 stems/m2 to about 346 stems/m2 (Moller 1999). Since the two densities that we tested were both under the average natural density of Spartina shoots, adding several treatments to the experiment we conducted that include natural densities would help determine the most effective densities for attenuating waves. Also, waves tend to be more effectively attenuated with denser marshes (Anderson et al. 2013). Some factors that would also be useful to study in the future would be testing wave attenuation at various sites that differ in morphology, testing effectiveness of different dowel diameters, and length of the plot parallel to shore. All of these aspects could be tested and when an optimal value is found, could be recommended to customers who may want to utilize this shore-protecting mechanism.

4.3 Sediment and Nutrient Processes

While there were visual changes in grain size, there was no statistically significant difference in grain size between the treatments and the control. The trend, however, showed that the 50 dowels/ m2 had the smallest average grain size and thus accumulated the most sediment. Qualitatively, the sediment cores used for grain size analysis showed visual differences within the top centimeter of the sediment.

The sediment cores had a visual layer of deposited sediment that suggest an effective marsh mimic; these layers may have formed as fine particles settled out of the water from the time the cores were taken to the time they were opened for analysis. A repetition of this study using a larger sample size would be useful to determine whether this marsh mimic prototype would consistently trap fine particles in its water column that would eventually be deposited on the benthic substrate. Although there was no statistical significance, our visual observations gave indication that some smaller particles were being trapped by the dowel treatments. This means that our marsh mimic could have the potential to provide processes of sediment trapping from the water column, which is crucial if marsh recruitment and growth are to occur (add a ref here?).

Dowel density did not show a statistically significant effect between treatments on denitrification rates, neither before nor after a nitrate pulse was added. However, the denitrification rates were significantly enhanced by the presence of dowels in the system. There was almost no difference between ambient and nitrogen pulse rates in the control, but all plots with dowels showed a statistically significant increase in denitrification rates, with the greatest change occurring in the 100 dowels/m2 plots. This showed that the presence of dowels may augment the denitrification capacity of a system after a nitrogen loading event, like a rain storm.

Sediment organic matter had greater variance in values as the density increased with the highest variance being in the 150 dowel density treatment. This shows that dowel densities may have an effect on sediment organic matter, but it may simply be that, because of the short time they were in place or other environmental conditions, they were not able to affect all the plots

uniformly, giving us a wide variety of ranges. With more repetition of the treatments, a statistically significant pattern could emerge.

The chlorophyll a levels used to measure epiphytic algal growth were highest in the 100 dowels/m2 treatment and statistically significant from the other densities. Similar levels of chlorophyll were found at the bulkhead site which had all 100 dowels/m2 treatments. There were no statistically significant differences between benthic chlorophyll a levels between the treatments. The variance was highest in the control, but the medians were about the same until the 150 dowel density treatment. The lower level and variance may be due to shading caused the large amount of dowels, hinting there may be a max density of 100 dowels to promote benthic algal growth. Both epiphytic and benthic algae are important because they form the basis for a large part of the food web, in some ecosystems they make up 60% of the total benthic primary production (Moncreiff and Sullivan, 2001).

Our methods for this study could only include measuring the top centimeter of each of our cores for grain size; however, in the future we might suggest creating a method that would account for changes in grain size before and after the installation of the dowels at each site. We tried to measure the top 1 cm of sediment and then compare that to be subsequent 2 centimeters below that sediment, but we were not equipped with tools that allowed us to measure to 3 total centimeters of depth. In the future we would also recommend either more replicate sites and to take more cores per site in order to enlarge the sample size and reduce bias.

4.4 Product design

In light of the data we have gathered based on the mimic salt marsh, we have proposed a conceptual business plan and product model to reflect a potential nature-based product. Our framework for this product was organized and designed around readily-available, renewable natural resources that would help to protect customers’ shoreline property and its value. In doing this, we also hope to address environmental problems caused by gray infrastructure; for example, bulkheads cause scour that decreases the area of surrounding salt marsh and its ability to retreat naturally, while also facilitating harmful erosion downstream. Our mimic salt marsh is a nature-based product would protect property value while enhancing the natural viewscape, saving the customer money and time, and minimizing any negative effects on the environment. In addition, the cost of failure would be minimized using our product versus a bulkhead due to the differences in materials and construction. Bulkheads rely purely on retaining sediment, by drastically changing the landscape of the property, whereas our product builds and maintains new sediment deposits with negligible alteration to existing land while using much less construction material.

Our proposed product reflects the outcomes of our research in terms of which dowel density would provide the most overall ecosystem services. The materials used would be sustainable and non-invasive or intrusive to the environment. Bamboo became the material of choice because of its natural prevalence and classification as a pest species in North Carolina.

The structure of our nature-based product would be similar to our experiment but rather than wooden birch dowels, bamboo dowels would be used. To transform this science into a

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key resources would be bamboo lumber, used to construct the base of our product as well as the dowels. Key activities on the production side would be the assembly of the base and assurance that the dowels fit into the model; while, key activities on the customer’s side would be the actual installation of the product, which is fairly simple. The customer would insert the dowels into the base, dig out a four inch deep 1 m by 1 m plot where they want to place the unit, place the base and dowels into the sediment, and refill the box with sediment. Our value proposition is mainly comprised of the differences in cost of gray infrastructure, such as bulkheads and stone sills, compared to the potential halving of those costs by the cost of bamboo lumber. Another part of the value proposition is that this product would not need huge repairs should it fail like a bulkhead. Installing and repairing a bulkhead not only costs money, but also costs the customer a lot of time. That is something we hope to avoid with this product. Our customer relationships would be established and strengthened by the use of incentive programs, trial periods, and discounts. Channels of delivery were considered most in the design portion of our model. Creating an effective product that is stabilized yet is still light enough to have feasible shipping costs was the biggest part of the discussion, when it came to the “channel” portion of our business model. Lastly, we considered potential customers. Just like any business, they are the driving force behind the model. Our customers could have small-scale projects behind their homes, or a company could use our product to offset negative impacts of new development. Even conservation groups could use our product to facilitate the development of a living shoreline by providing a more hospitable environment for marsh grass growth and potentially the development of an oyster reef.

This capstone project faced many trials and tribulations throughout its duration. The sheer difficulty of installation of the dowels led us to change our dowel densities from literature values to a more physically and economically feasible level. Due to time constraints, we had little time to adjust our plots once they were installed. To our great relief, all of the plots survived Hurricane Matthew, a category 1 hurricane that passed over Morehead City in early October. Some damage was sustained in the form of broken dowels, but the plots remained stable. Another limitation is that we could only gather data during the fall, which is not the most productive season for many aspects that we studied. Nutrient cycles slow down and some organisms move to the upper estuary for the winter, both factors which could have been accounted for if we had the ability to continue our study over a few seasons. Moving forward with the wide breadth of data collected and a model in hand, we believe that in order to make a proper assessment of our hypothesis, the study would need to be continued across all seasons. This would allow the data to reflect any seasonal changes as well as solidify our base of knowledge necessary to create the most efficient product possible. We hope that this technology and product would lessen the dependence on harsher methods of shoreline hardening and reinforcement.

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