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

Thumbnail Image
Date
2018-05-20
Authors
Donatelli, Carmine
Ganju, Neil K.
Fagherazzi, Sergio
Leonardi, Nicoletta
Linked Authors
Alternative Title
Date Created
Location
DOI
10.1029/2018GL078056
Replaced By
Keywords
Seagrass
Sediment transport
COAWST
Salt marsh
Ecosystems
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.
Description
Author Posting. © American Geophysical Union, 2018. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 45 (2018): 4933-4943, doi:10.1029/2018GL078056.
Embargo Date
Citation
Geophysical Research Letters 45 (2018): 4933-4943
Cruises
Cruise ID
Cruise DOI
Vessel Name