Estuaries: Where the River Meets the Sea. Estuaries. Where freshwater rivers meet the salty open sea. There is a lot to love in an estuary. A popular destination for fishing, boating, birding and hiking, estuaries are a beautiful place to be. Miles of beaches, flowing grasses, marshes, creeks, and streams. This salty freshwater mix is where life begins and is the nursing grounds for 75% of the fish we catch. Estuaries are lined with marshes and sea grasses that filter water flowing to the ocean and act as a buffer protecting us from coastal storms. NOAA works closely with coastal states to manage the National Estuarine Research Reserve System of 28 protected areas along the nation’s coasts. These valuable reserves are living laboratories for scientists and exciting, hands-on classrooms for students and teachers. At the reserves, scientists study sea level rise, water pollution, erosion, and impacts of human development. These studies provide strong scientific knowledge to help us create healthy, productive estuaries. (NOAA)