Seagrass impact on sediment exchange between tidal flats and salt Marsh, and the sediment budget of shallow bays

Geophysical Research Letters
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Abstract

Seagrasses are marine flowering plants that strongly impact their physical and biological surroundings and are therefore frequently referred to as ecological engineers. The effect of seagrasses on coastal bay resilience and sediment transport dynamics is understudied. Here we use six historical maps of seagrass distribution in Barnegat Bay, USA, to investigate the role of these vegetated surfaces on the sediment storage capacity of shallow bays. Analyses are carried out by means of the Coupled-Ocean-Atmosphere-Wave-Sediment Transport (COAWST) numerical modeling framework. Results show that a decline in the extent of seagrass meadows reduces the sediment mass potentially stored within bay systems. The presence of seagrass reduces shear stress values across the entire bay, including unvegetated areas, and promotes sediment deposition on tidal flats. On the other hand, the presence of seagrasses decreases suspended sediment concentrations, which in turn reduces the delivery of sediment to marsh platforms. Results highlight the relevance of seagrasses for the long-term survival of coastal ecosystems, and the complex dynamics regulating the interaction between subtidal and intertidal landscapes.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Seagrass impact on sediment exchange between tidal flats and salt Marsh, and the sediment budget of shallow bays
Series title Geophysical Research Letters
DOI 10.1029/2018GL078056
Volume 45
Issue 10
Year Published 2018
Language English
Publisher American Geophysical Union
Contributing office(s) Woods Hole Coastal and Marine Science Center
Description 11 p.
First page 4933
Last page 4943
Country United States
State New Jersey
Other Geospatial Barnegat Bay