The Cape Cod landscape is one of many estuaries and salt marshes. These ecosystems can be found along both the bay and ocean shores in what is known as the intertidal zone; any area that is regularly inundated by the tide.
The term estuary is a broad one used to describe an area where fresh water meets the sea. As freshwater flows into a marine environment, it carries with it nutrients from terrestrial run-off. Thus, estuaries are almost always associated with high biological productivity making them important ecological and economic systems. For many marine fishes and invertebrates estuaries serve as habitat in which they can find shelter, breed, and forage. Estuaries also have tremendous recreational value as they offer an ideal setting for fishing, kayaking, and photography.
Salt marshes are also located in the intertidal zone. In New England, they are marked by communities of salt-tolerant vegetation often found among a mosaic of meandering tidal creeks. Most often, salt marshes occur in low-energy locations where the land is some-what sheltered from the direct flow of the tide. Salt marshes are among the most biologically productive ecosystems on earth and play an important role in filtering out nutrients. Salt marshes serve as critical habitat for a host of important animals species including fishes, shellfish, and birds.
Due to the critical nature of these systems, the Cape Cod National Seashore has undertaken an ambitious program of estuarine monitoring and salt marsh restoration. You can learn much more about these by visiting the links below: