Estuaries are partially enclosed, coastal water bodies where freshwater from rivers and streams mixes with salt water from the ocean. The United State’s largest estuary is the Chesapeake Bay along the mid-Atlantic coast. These transitional zones are among the most nutrient-rich and productive natural habitats in the world. Estuaries are valuable regions that are ideal places for tourism, fisheries, and recreational activities; they filter sediments and pollutants from water passing through them; and serve as important protective buffers for natural and built environments that absorb flood waters and dissipate ocean storm surges. 

NASA’s instruments and platforms keep watch over estuaries to supply researchers and coastal managers with the information they need to understand and protect their special benefits from human over-intrusion and climate change. To help preserve estuaries, NASA’s historical and current estuary imagery and related data provide unique, high-value perspectives on their processes and role as coastal landforms.