Influence of Sediment Availability, Vegetation, and Sea Level Rise on the Development of Tidal Marshes in the Delaware Bay: A Review

Stammermann, Ramona; Piasecki, Michael

doi:10.2112/jcoastres-d-11-00143.1

Cited by 9 publications

(10 citation statements)

References 109 publications

(184 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The 20th century was characterized by a decrease of sediment export from the Delaware Estuary and Chesapeake Bay (14,22), which constitute the main sediment sources for the New Jersey and Virginia marshes. Sediment inventories suggest that sediment removed from the Delaware Estuary by periodic dredging is not replenished by the input from upstream tributaries (Fig.…”

Section: Discussionmentioning

confidence: 99%

Critical width of tidal flats triggers marsh collapse in the absence of sea-level rise

Mariotti

Fagherazzi

2013

Proc. Natl. Acad. Sci. U.S.A.

250

263

View full text Add to dashboard Cite

High rates of wave-induced erosion along salt marsh boundaries challenge the idea that marsh survival is dictated by the competition between vertical sediment accretion and relative sea-level rise. Because waves pounding marshes are often locally generated in enclosed basins, the depth and width of surrounding tidal flats have a pivoting control on marsh erosion. Here, we show the existence of a threshold width for tidal flats bordering salt marshes. Once this threshold is exceeded, irreversible marsh erosion takes place even in the absence of sea-level rise. This catastrophic collapse occurs because of the positive feedbacks among tidal flat widening by wave-induced marsh erosion, tidal flat deepening driven by wave bed shear stress, and local wind wave generation. The threshold width is determined by analyzing the 50-y evolution of 54 marsh basins along the US Atlantic Coast. The presence of a critical basin width is predicted by a dynamic model that accounts for both horizontal marsh migration and vertical adjustment of marshes and tidal flats. Variability in sediment supply, rather than in relative sea-level rise or wind regime, explains the different critical width, and hence erosion vulnerability, found at different sites. We conclude that sediment starvation of coastlines produced by river dredging and damming is a major anthropogenic driver of marsh loss at the study sites and generates effects at least comparable to the accelerating sea-level rise due to global warming.salt marsh boundary erosion | wave erosion W ave-induced boundary erosion is a leading process threatening salt marshes (1, 2), but it is remarkably unexplored compared with the vertical dynamics of the marsh platform (3, 4). Wave-induced boundary erosion is particularly relevant along coastlines with limited subsidence such as the Mid-Atlantic coast of the United States, where large marsh areas are deteriorating (5, 6) despite marsh accretion keeping pace with contemporary rates of sea-level rise (7,8). Here, we focus on the evolution of three salt marsh sites on the US Atlantic Coast, subjected to different rates of wave-induced boundary erosion: Cape May, NJ, Virginia Coast Reserve, VA, and Charleston Sound, SC (Fig. 1). All sites are characterized by barrier islands sheltering shallow bays with extensive salt marshes and tidal flats. The bays are connected to the open sea by multiple inlets, experience limited direct riverine inputs (9, 10), and are subject to similar wind conditions (SI Text). Relative sea-level rise (RSLR) is on the order of 2 mm/y and tidal range of ∼1.4 m (SI Text). These embayments are characterized by rounded tidal flats surrounded by salt marshes, which are referred to as marsh basins (11,12).Stevenson et al. (13) reported loss of brackish marshes driven by the enlargement of marsh basins, referred to by the authors as ponds. They suggested the existence of a pond threshold width that, once exceeded, leads to ponds widening by wave-induced boundary erosion. Here, we expand this idea by (i) developing a physical...

show abstract

Section: Discussionmentioning

confidence: 99%

Critical width of tidal flats triggers marsh collapse in the absence of sea-level rise

Mariotti

Fagherazzi

2013

Proc. Natl. Acad. Sci. U.S.A.

250

263

View full text Add to dashboard Cite

show abstract

“…From 1949From -1978, bald cypress (Taxodium distichum) transitioned to brackish marsh species including black needlerush (Juncus roemerianus) and chairmaker's bulrush (Scirpus olneyi) in Mott Creek [19]. Twelve sites were also studied from 2000-2009 and four of these experienced vegetation changes: (1) freshwater emergent vegetation transitioned to saltwater emergent vegetation, (2) forested wetlands transitioned to herbaceous, and (3) bald cypress showed salt stress [20].…”

Section: Study Areamentioning

confidence: 99%

“…Under natural conditions, coastal wetlands accrete sediment from these sources and transgress inland at the same rate as RSLR [1]. If RSLR surpasses the rate at which coastal wetlands accumulate sediment, wetlands will transition to intertidal mudflats or open water [2][3][4]. Additionally, the salt wedge dictates the freshwater/saltwater boundary while the tidal range, ground elevation, and topography influence the duration and extent of tidal inundation and salinity.…”

Section: Introductionmentioning

confidence: 99%

A Multi-Decadal Investigation of Tidal Creek Wetland Changes, Water Level Rise, and Ghost Forests

Magolan

Halls

2020

Remote Sensing

View full text Add to dashboard Cite

Coastal wetlands play a vital role in protecting coastlines, which makes the loss of forested and emergent wetlands devastating for vulnerable coastal communities. Tidal creeks are relatively small hydrologic areas that feed into larger estuaries, are on the front lines of the interface between saltwater and freshwater ecosystems, and are potentially the first areas to experience changes in sea level. The goal of this study was to investigate wetland changes through time at two tidal creeks (Smith Creek and Town Creek) of the Cape Fear River estuary in southeastern North Carolina, USA, to determine if there is a spatial relationship between habitat change, physical geography characteristics, and the rate of wetland migration upstream. Historic aerial photography and recent satellite imagery were used to map land cover and compute change through time and were compared with derived physical geography metrics (sinuosity, creek width, floodplain width, floodplain elevation, and creek slope). The primary results were: (1) there was a net gain in emergent wetlands even accounting for the area of wetlands that became water, (2) wetlands have migrated upstream at an increasing rate through time, (3) land cover change was significantly different between the two creeks (P = 0.01) where 14% (67.5 ha) of Smith Creek and 18% (272.3 ha) of Town Creek transitioned from forest to emergent wetland, and (4) the transition from emergent wetland to water was significantly related to average change in creek width, floodplain elevation, and average water level. In conclusion, this research correlated habitat change with rising water level and identified similarities and differences between neighboring tidal creeks. Future research could apply the methodologies developed here to other coastal locations to further explore the relationships between tides, sea level, land cover change, and physical geography characteristics.The coastal counties surrounding the Cape Fear River have experienced a large increase in urban population where, from 1970 to 2010, New Hanover County experienced a 144% increase in population and Brunswick County a 343% increase [24]. With population growth, and the potential loss of natural areas including forested wetlands, there is an increased coastal vulnerability to storm surge inundation and pluvial flooding. To investigate land cover change under increasing tidal range, relative sea-level rise, and urban development, two tidal creeks of the Cape Fear River estuary, Smith Creek (34.257029, -77.929373) and Town Creek (34.135822, -78.001620) were investigated in this study (Figure 1). Town Creek, 33 km from the mouth of the Cape Fear River, is characterized by expansive wetlands, and is very long for a tidal creek at 53 km [25]. Further upstream, 18 km from Town Creek, is Smith Creek which is much shorter in length (17 km) and is surrounded by urban development. While Smith Creek and Town Creek have notable differences, these creeks were chosen because: (1) they are in close proximity, which is good for compari...

show abstract

“…Exacerbated by local temperatures projected to increase 1.5-3.5 • F (winter) and 2.5-4 • F (summer), northeastern U.S. sea-level rise (SLR) is predicted to be greater than projected global averages, threatening long-term sustainability of the region's coastline and with the subsequent loss of existing estuarine wetlands (CCSP 2009;Gornitz, Couch, and Hartig 2002;Karl, Melillo, and Peterson 2009;Miller et al 2013;Strauss et al 2012). The HRE's urban wetlands are not accreting new sediment fast enough to match rising seas (Gornitz, Couch, and Hartig 2002;Kirshen et al 2007;Nicholls and Cazenave 2010;Scavia et al 2002;Stammermann and Piasecki 2012;Yin, Schlesinger, and Stouffer 2009) and the density of regional development precludes significant landward migration (Kennish 2001). Three HRE restoration projects (for detailed site history and descriptions see Ravit, Weis, and Rounds, in press) illustrate the three types of restoration activities described above.…”

Section: Hudson-raritan Estuary (Hre) Restorationsmentioning

confidence: 99%

Clean Water Act Section 404 and Coastal Marsh Sustainability

Ravit

Weis

2014

Coastal Management

View full text Add to dashboard Cite

The "no net wetland loss" goal has not been met in urban coastal regions where conditions continue to exacerbate wetland losses. Under the Clean Water Act (Section 404) the U.S. Army Corps of Engineers and U. S. Environmental Protection Agency share responsibility for regulating placement of fill material in wetlands. The 'no discharge of fill' rules threaten coastal wetlands with continuing losses due to effects of changing climate, including rising sea levels, higher storm surges, and flooding. Where inland migration is limited by development, or where sediment accretion rates are lower than the rate of sea level rise, urban wetlands will be lost unless marsh topography is elevated. We explored regulatory and design approaches in recent Hudson-Raritan Estuary (HRE), San Francisco Bay Estuary and coastal Louisiana restorations, including creation of new marshland using dredge material. Questions related to sea level rise, ecological position within the landscape, or potential effects of extreme storm events were not addressed in the HRE restoration designs; these concerns were taken into account in other regions. We suggest benefits of marsh 'replenishment' should be acknowledged in Federal regulatory policy and that consistent policies supportive of low-lying coastal marsh preservation in all regions should be enacted.

show abstract

Influence of Sediment Availability, Vegetation, and Sea Level Rise on the Development of Tidal Marshes in the Delaware Bay: A Review

Cited by 9 publications

References 109 publications

Critical width of tidal flats triggers marsh collapse in the absence of sea-level rise

Critical width of tidal flats triggers marsh collapse in the absence of sea-level rise

A Multi-Decadal Investigation of Tidal Creek Wetland Changes, Water Level Rise, and Ghost Forests

Clean Water Act Section 404 and Coastal Marsh Sustainability

Contact Info

Product

Resources

About