Observations of tidal and springtime sediment transport in the upper Delaware Estuary

Cook, Timothy L.; Sommerfield, Christopher K.; Wong, Kuo‐Chuin

doi:10.1016/j.ecss.2006.10.014

Cited by 51 publications

(48 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Gosnell et al (2015) conclude that sediment resuspension supplies particulates to the water column within the ETM. Previous studies also suggest that suspended particulates tend to get trapped in the upper estuary and not exported out of the ETM (Cook et al 2007; Sommerfield and Wong 2011). …”

Section: Discussionmentioning

confidence: 94%

Methylmercury Bioaccumulation in an Urban Estuary: Delaware River, USA

Buckman

Taylor

Broadley

et al. 2017

Estuaries and Coasts

View full text Add to dashboard Cite

Spatial variation in mercury (Hg) and methylmercury (MeHg) bioaccumulation in urban coastal watersheds reflects complex interactions between Hg sources, land use, and environmental gradients. We examined MeHg concentrations in fauna from the Delaware River estuary, and related these measurements to environmental parameters and human impacts on the waterway. The sampling sites followed a north to south gradient of increasing salinity, decreasing urban influence, and increasing marsh cover. Although mean total Hg in surface sediments (top 4cm) peaked in the urban estuarine turbidity maximum and generally decreased downstream, surface sediment MeHg concentrations showed no spatial patterns consistent with the examined environmental gradients, indicating urban influence on Hg loading to the sediment but not subsequent methylation. Surface water particulate MeHg concentration showed a positive correlation with marsh cover whereas dissolved MeHg concentrations were slightly elevated in the estuarine turbidity maximum region. Spatial patterns of MeHg bioaccumulation in resident fauna varied across taxa. Small fish showed increased MeHg concentrations in the more urban/industrial sites upstream, with concentrations generally decreasing farther downstream. Invertebrates either showed no clear spatial patterns in MeHg concentrations (blue crabs, fiddler crabs) or increasing concentrations further downstream (grass shrimp). Best-supported linear mixed models relating tissue concentration to environmental variables reflected these complex patterns, with species specific model results dominated by random site effects with a combination of particulate MeHg and landscape variables influencing bioaccumulation in some species. The data strengthen accumulating evidence that bioaccumulation in estuaries can be decoupled from sediment MeHg concentration, and that drivers of MeHg production and fate may vary within a small region.

show abstract

Section: Discussionmentioning

confidence: 94%

Methylmercury Bioaccumulation in an Urban Estuary: Delaware River, USA

Buckman

Taylor

Broadley

et al. 2017

Estuaries and Coasts

View full text Add to dashboard Cite

show abstract

“…In reality, accumulation and erosion may be localized on the shoals rather than laterally uniform across the estuary . Similarly, observations in the Delaware Estuary have shown that inter-annual storage of sediment in depositional regions can exceed the annual sediment input from the river (Cook et al 2007).…”

Section: Long-term Sediment Fluxmentioning

confidence: 96%

Episodic and Long-Term Sediment Transport Capacity in The Hudson River Estuary

Ralston

Geyer

2009

Estuaries and Coasts

View full text Add to dashboard Cite

A tidally averaged model of estuarine dynamics is used to estimate sediment transport in the Hudson River estuary over the period 1918 to 2005. In long-term and seasonal means, along-channel gradients in sediment flux depend on the estuarine salinity gradient and along-channel depth profile. Lateral depth variation across the estuary affects the near-bottom baroclinic circulation and consequently the direction of net sediment flux, with generally up-estuary transport in the channel and down-estuary transport on the shoals. Sediment transport capacity in the lower estuary depends largely on river discharge, but is modified by the timing of discharge events with respect to the spring-neap cycle and subtidal fluctuations in sea level. Sediment transport capacity also depends on the duration of high-discharge events relative to the estuarine response time, a factor that varies seasonally with discharge and estuarine length. Sediment fluxes are calculated with the assumption that over long periods, the system approaches morphological equilibrium and sediment accumulation equals sea level rise. The inferred across-and alongchannel distributions of sediment erodibility correspond with observations of bed properties. Equilibrium is assumed at long time scales, but at annual to decadal time scales the estuary can develop an excess or deficit of sediment relative to equilibrium. On average, sediment accumulates in the estuary during low-and high-discharge periods and is exported during moderate discharge. During high-discharge periods, maximum export coincides with maximum sediment supply from the watershed, but the nearly cubic discharge dependence of fluvial sediment supply overwhelms the roughly linear increase in estuarine transport capacity. Consequently, sediment accumulates in the estuary during the highest flow conditions. Uncertainty remains in the model, particularly with sediment properties and boundary conditions, but the results clearly indicate variability in the sediment mass balance over long time scales due to discharge events.

show abstract

“…Extensive sediment inventories have been made since the 1970s, including the determination of suspended loads from the tributaries (Biggs et al, 1983;Mansue and Commings, 1974), bottom sediment distribution (Biggs et al, 1983;Sommerfield and Madsen, 2003;Walsh, 2004;Wilson and Madsen, 2006), and investigations of the dynamics in the Delaware Bay turbidity maximum (Church et al, 2006;Cook, Sommerfield, and Wong, 2007;Sommerfield and Wong, 2011). It is assumed that presently more sediment is removed from the Delaware Estuary system by maintenance dredging than can be replenished by sediment transport from upstream tributaries.…”

Section: Research On Delaware Estuary Marshesmentioning

confidence: 99%