Estuary

A partially enclosed body of water where saltwater from the sea mixes with freshwater from rivers, streams and creeks. These areas are subject to tidal forces, like the sea, but are sheltered from the full force of ocean winds and waves by the coastline, marshes, and wetlands. (Note: Estuary-like areas of the Great Lakes also are included in the national system based on a definition from the Coastal Zone Management Act.)

The thin zone along a coastline where freshwater systems and rivers meet and mix with a salty ocean (such as a bay, mouth of a river, salt marsh, lagoon).

A water body where salt and fresh water meet resulting in brackish water. These areas usually have associated marshlands and are critical nursery and feeding habitat for a variety of marine species.

In hydrologic terms, the thin zone along a coastline where freshwater systems and rivers meet and mix with a salty ocean (such as a bay, mouth of a river, salt marsh, lagoon).