Declining Sediments and Rising Seas: an Unfortunate Convergence for Tidal Wetlands

  title={Declining Sediments and Rising Seas: an Unfortunate Convergence for Tidal Wetlands},
  author={Nathaniel B. Weston},
  journal={Estuaries and Coasts},
The availability of suspended sediments will be a dominant factor influencing the stability of tidal wetlands as sea levels rise. Watershed-derived sediments are a critical source of material supporting accretion in many tidal wetlands, and recent declines in wetland extent in several large river delta systems have been attributed in part to declines in sediment delivery. Little attention has been given, however, to changes in sediment supply outside of large river deltas. In this study… 
Coastal sedimentation across North America doubled in the 20th century despite river dams
The proliferation of dams since 1950 promoted sediment deposition in reservoirs, which is thought to be starving the coast of sediment and decreasing the resilience of communities to storms and
Influence of Inundation and Suspended-Sediment Concentrations on Spatiotemporal Sedimentation Patterns in a Tidal Freshwater Marsh
Long-term marsh sustainability is threatened by environmental changes, especially accelerated rates of sea-level rise (SLR) and changing fluvial sediment supplies. Although direct observations of
Sediment Budget Estimates for a Highly Impacted Embayment with Extensive Wetland Loss
External sediment supply is an important control on wetland morphology and vulnerability to storms, sea-level rise, and land use change. Constraining sediment supply and net budgets is difficult due
Lateral Marsh Edge Erosion as a Source of Sediments for Vertical Marsh Accretion
With sea level rise accelerating and sediment inputs to the coast declining worldwide, there is concern that tidal wetlands will drown. To better understand this concern, sources of sediment
Controls on Sediment Accretion and Blue Carbon Burial in Tidal Saline Wetlands: Insights From the Oregon Coast, USA
Oregon estuaries provide important opportunities to assess controls on tidal saline wetland carbon burial and sediment accretion as both rates of relative sea level rise (RSLR; −1.4 ± 0.9 to 2.8 ±
Coastal wetland response to sea level rise in Connecticut and New York
Role of delta‐front erosion in sustaining salt marshes under sea‐level rise and fluvial sediment decline
Accelerating sea‐level rise and decreasing riverine sediment supply are widely considered to lead to global losses of deltaic marshes and their valuable ecosystem services. However, little is known


Salt marsh ecosystems are maintained by the dominant macrophytes that regulate the elevation of their habitat within a narrow portion of the intertidal zone by accumulating organic matter and
Rapid wetland expansion during European settlement and its implication for marsh survival under modern sediment delivery rates
Fluctuations in sea-level rise rates are thought to dominate the formation and evolution of coastal wetlands. Here we demonstrate a contrasting scenario in which land-use–related changes in sediment
Coastal Wetland Vulnerability to Relative Sea-Level Rise: Wetland Elevation Trends and Process Controls
The distribution of tidal saline wetlands (e.g., salt marshes and mangroves) is increasingly impacted by global environmental change, including human alteration of the world’s coasts and sea-level
The response of coastal marshes to sea‐level rise: Survival or submergence?
In order to maintain an elevation in the intertidal zone at which marsh vegetation can survive, vertical accretion of the marsh surface must take place at a rate at least equal to the rate of
Increased Terrestrial to Ocean Sediment and Carbon Fluxes in the Northern Chesapeake Bay Associated With Twentieth Century Land Alteration
We calculated Chesapeake Bay (CB) sediment and carbon fluxes before and after major anthropogenic land clearance using robust monitoring, modeling and sedimentary data. Four distinct fluxes in the
Watershed land use and river engineering drive wetland formation and loss in the Mississippi River birdfoot delta
The Mississippi River basin was developed for agriculture at an unprecedented scale and intensity within the last 200 yr. These changes favored erosion and sediment transport, which were subsequently
Linking land use, erosion and sediment yields in river basins
Results obtained from erosion plots and catchment experiments provide clear evidence of the sensitivity of erosion rates to land use change and related human activity. Evidence for the impact of land
Limits on the adaptability of coastal marshes to rising sea level
Assumptions of a static landscape inspire predictions that about half of the world's coastal wetlands will submerge during this century in response to sea‐level acceleration. In contrast, we use
A coupled geomorphic and ecological model of tidal marsh evolution
  • M. Kirwan, A. Murray
  • Environmental Science
    Proceedings of the National Academy of Sciences
  • 2007
A 3D model of tidal marsh accretion and channel network development that couples physical sediment transport processes with vegetation biomass productivity is developed that promotes a metastable equilibrium where the platform maintains elevation relative to a rapidly rising sea level.
Coastal eutrophication as a driver of salt marsh loss
It is shown that nutrient levels commonly associated with coastal eutrophication increased above-ground leaf biomass, decreased the dense, below-ground biomass of bank-stabilizing roots, and increased microbial decomposition of organic matter, demonstrating that nutrient enrichment can be a driver of salt marsh loss.