Low-Elevation Wetlands (IMAGE) Virginia Institute of Marine Science Caption Low-elevation wetlands like this Spartina marsh in Massachusetts' Plum Island Estuary are frequently flooded by tides that deposit sediment and cause the marsh to build up at a fast rate (approximately 5-10 millimeters per year). Credit Photo by Matt Kirwan. Usage Restrictions One-time use only. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.