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.
Estuaries are some of the most productive ecosystems in the world. Many animal species rely on estuaries for food and as places to nest and breed. Humans communities also rely on estuaries for food, recreation, and jobs.
Of the 32 largest cities in the world, 22 are located on estuaries (Ross, 1995). Not surprisingly, human activities have led to a decline in the health of estuaries, making them one of the most threatened ecosystems on Earth. NOAA's National Estuarine Research Reserve System (NERRS), in partnership with coastal states, monitors the health of estuaries, educates the public about these ecosystems, and helps communities manage their coastal resources.
The Estuaries Tutorial is an overview of estuarine habitats, the threats facing them, and efforts to monitor and protect estuaries nationwide.
The Roadmap to Resources complements the information in the tutorial by directing you to specific online estuary-related materials from NOAA and other reliable resources.