Salt marsh reportedly lost 7 mm of sediment after 21 hours of simulated storm waves

Wave-height-dependent attenuation and vegetation damage

According to ScienceAlert, researchers moved 306 square meters of salt marsh from the Wadden Sea coast into the Delta Flume in Delft and exposed it to waves rising from 0.75 to 2 meters. After 21 hours, the marsh reportedly had lost 7 millimeters of sediment. The report says wave power was reduced by up to 50 percent for waves up to 1 meter, but by no more than 10 percent for waves over 1 meter. Vegetation was heavily damaged: 20–25 percent of the original above-ground biomass remained, and stem lengths were reduced by 47 percent.

The report describes one full-scale wave-flume experiment; it does not provide a directly comparable prior measurement for this marsh under the same conditions.

The reported experiment newly measured how a transplanted wild salt marsh responded to 21 hours of increasingly high simulated storm waves, including both sediment loss and wave-power attenuation.

The test offers a reported large-scale measurement of a salt marsh functioning alongside coastal defenses under severe simulated waves, while also showing that its wave-reducing effect was much smaller above 1 meter and that vegetation sustained substantial damage.