Estuaries are bodies of water and their surrounding coastal habitats typically found where rivers meet the sea. Estuaries harbor unique plant and animal communities because their waters are brackish—a mixture of fresh water draining from the land and salty seawater. Estuary, partly enclosed coastal body of water in which river water is mixed with seawater. In a general sense, the estuarine environment is defined by salinity boundaries rather than by geographic boundaries. Geography Estuary An estuary is a partially enclosed body of coastal water where fresh water from rivers and streams mixes with saltwater from the oceans. Estuaries and their surrounding lands are considered places of transition from land to sea. Although influenced by tides, they are also protected from the full force of ocean waves, winds and storms by landforms such as barrier islands or peninsulas. Estuarine environments are among the most productive on earth, creating more organic ... Learn about estuary, a brackish water body that is partly enclosed along the shore, with one or more rivers or streams flowing into it and a free access to the open sea. Explore the different types of estuaries based on geomorphological characteristics or water circulation patterns, and their history and impact on the environment.