There are basically four naturally occurring components of a salt marsh: The tidal water, the pluff mud, the cordgrass and oysters. Each of these plays a crucial role and each is reliant on the stability of the others for the salt marsh environment to succeed. The tides push the salty waters into the far reaches of the salt marsh and then suck the water out. This constant filling and flushing of the marshes allows for the dynamic exchange of nutrients to and from the ocean. The salinity of the water in the marsh is nearly the same as the ocean. The cordgrass helps keep the pluff mud in place, the mud accumulates and supports the root system of the grasses and from it emerges the vast oyster beds.